/add-ons/pjmt/Photoshop_IRB.php

<?



/******************************************************************************

*

* Filename:     Photoshop_IRB.php

*

* Description:  Provides functions for reading and writing information to/from

*               the 'App 13' Photoshop Information Resource Block segment of

*               JPEG format files

*

* Author:       Evan Hunter

*

* Date:         23/7/2004

*

* Project:      PHP JPEG Metadata Toolkit

*

* Revision:     1.11

*

* Changes:      1.00 -> 1.02 : changed get_Photoshop_IRB to work with corrupted

*                              resource names which Photoshop can still read

*               1.02 -> 1.03 : Fixed put_Photoshop_IRB to output "Photoshop 3.0\x00"

*                              string with every APP13 segment, not just the first one

*               1.03 -> 1.10 : changed get_Photoshop_IRB to fix processing of embedded resource names,

*                              after discovering that Photoshop does not process

*                              resource names according to the standard :

*                              "Adobe Photoshop 6.0 File Formats Specification, Version 6.0, Release 2, November 2000"

*                              This is an update to the change 1.00 -> 1.02, which was not fully correct

*                              changed put_Photoshop_IRB to fix the writing of embedded resource name,

*                              to avoid creating blank resources, and to fix a problem

*                              causing the IRB block to be incorrectly positioned if no APP segments existed.

*                              changed get_Photoshop_IPTC to initialise the output array correctly.

*               1.10 -> 1.11 : Moved code out of get_Photoshop_IRB into new function unpack_Photoshop_IRB_Data

*                              to allow reading of IRB blocks embedded within EXIF (for TIFF Files)

*                              Moved code out of put_Photoshop_IRB into new function pack_Photoshop_IRB_Data

*                              to allow writing of IRB blocks embedded within EXIF (for TIFF Files)

*                              Enabled the usage of $GLOBALS['HIDE_UNKNOWN_TAGS'] to hide unknown resources

*                              changed Interpret_IRB_to_HTML to allow thumbnail links to work when

*                              toolkit is portable across directories

*

*

* URL:          http://electronics.ozhiker.com

*

* Copyright:    Copyright Evan Hunter 2004

*

* License:      This file is part of the PHP JPEG Metadata Toolkit.

*

*               The PHP JPEG Metadata Toolkit is free software; you can

*               redistribute it and/or modify it under the terms of the

*               GNU General Public License as published by the Free Software

*               Foundation; either version 2 of the License, or (at your

*               option) any later version.

*

*               The PHP JPEG Metadata Toolkit is distributed in the hope

*               that it will be useful, but WITHOUT ANY WARRANTY; without

*               even the implied warranty of MERCHANTABILITY or FITNESS

*               FOR A PARTICULAR PURPOSE.  See the GNU General Public License

*               for more details.

*

*               You should have received a copy of the GNU General Public

*               License along with the PHP JPEG Metadata Toolkit; if not,

*               write to the Free Software Foundation, Inc., 59 Temple

*               Place, Suite 330, Boston, MA  02111-1307  USA

*

*               If you require a different license for commercial or other

*               purposes, please contact the author: evan@ozhiker.com

*

******************************************************************************/



// Change: as of version 1.11 - added to ensure the HIDE_UNKNOWN_TAGS variable is set even if EXIF.php is not included

if ( !isset( $GLOBALS['HIDE_UNKNOWN_TAGS'] ) )     $GLOBALS['HIDE_UNKNOWN_TAGS']= FALSE;



include_once 'IPTC.php';

include_once 'Unicode.php';







// TODO: Many Photoshop IRB resources not interpeted

// TODO: Obtain a copy of the Photoshop CS File Format Specification

// TODO: Find out what Photoshop IRB resources 1061, 1062 & 1064 are

// TODO: Test get_Photoshop_IRB and put_Photoshop_IRB with multiple APP13 segments



/******************************************************************************

*

* Function:     get_Photoshop_IRB

*

* Description:  Retrieves the Photoshop Information Resource Block (IRB) information

*               from an App13 JPEG segment and returns it as an array. This may

*               include IPTC-NAA IIM Information. Uses information

*               supplied by the get_jpeg_header_data function

*

* Parameters:   jpeg_header_data - a JPEG header data array in the same format

*                                  as from get_jpeg_header_data

*

* Returns:      IRBdata - The array of Photoshop IRB records

*               FALSE - if an APP 13 Photoshop IRB segment could not be found,

*                       or if an error occured

*

******************************************************************************/



function get_Photoshop_IRB( $jpeg_header_data )

{

        // Photoshop Image Resource blocks can span several JPEG APP13 segments, so we need to join them up if there are more than one

        $joined_IRB = "";





        //Cycle through the header segments

        for( $i = 0; $i < count( $jpeg_header_data ); $i++ )

        {

                // If we find an APP13 header,

                if ( strcmp ( $jpeg_header_data[$i]['SegName'], "APP13" ) == 0 )

                {

                        // And if it has the photoshop label,

                        if( strncmp ( $jpeg_header_data[$i]['SegData'], "Photoshop 3.0\x00", 14) == 0 )

                        {

                                // join it to the other previous IRB data

                                $joined_IRB .= substr ( $jpeg_header_data[$i]['SegData'], 14 );

                        }

                }

        }



        // If there was some Photoshop IRB information found,

        if ( $joined_IRB != "" )

        {

                // Found a Photoshop Image Resource Block - extract it.

                // Change: Moved code into unpack_Photoshop_IRB_Data to allow TIFF reading as of 1.11

                return unpack_Photoshop_IRB_Data( $joined_IRB );



        }

        else

        {

                // No Photoshop IRB found

                return FALSE;

        }



}



/******************************************************************************

* End of Function:     get_Photoshop_IRB

******************************************************************************/





















/******************************************************************************

*

* Function:     put_Photoshop_IRB

*

* Description:  Adds or modifies the Photoshop Information Resource Block (IRB)

*               information from an App13 JPEG segment. If a Photoshop IRB already

*               exists, it is replaced, otherwise a new one is inserted, using the

*               supplied data. Uses information supplied by the get_jpeg_header_data

*               function

*

* Parameters:   jpeg_header_data - a JPEG header data array in the same format

*                                  as from get_jpeg_header_data

*               new_IRB_data - an array of the data to be stored in the Photoshop

*                              IRB segment. Should be in the same format as received

*                              from get_Photoshop_IRB

*

* Returns:      jpeg_header_data - the JPEG header data array with the

*                                  Photoshop IRB added.

*               FALSE - if an error occured

*

******************************************************************************/



function put_Photoshop_IRB( $jpeg_header_data, $new_IRB_data )

{

        // Delete all existing Photoshop IRB blocks - the new one will replace them



        //Cycle through the header segments

        for( $i = 0; $i < count( $jpeg_header_data ) ; $i++ )

        {

                // If we find an APP13 header,

                if ( strcmp ( $jpeg_header_data[$i]['SegName'], "APP13" ) == 0 )

                {

                        // And if it has the photoshop label,

                        if( strncmp ( $jpeg_header_data[$i]['SegData'], "Photoshop 3.0\x00", 14) == 0 )

                        {

                                // Delete the block information - it needs to be rebuilt

                                array_splice( $jpeg_header_data, $i, 1 );

                        }

                }

        }





        // Now we have deleted the pre-existing blocks





        // Retrieve the Packed Photoshop IRB Data

        // Change: Moved code into pack_Photoshop_IRB_Data to allow TIFF writing as of 1.11

        $packed_IRB_data = pack_Photoshop_IRB_Data( $new_IRB_data );



        // Change : This section changed to fix incorrect positioning of IRB segment, as of revision 1.10

        //          when there are no APP segments present



        //Cycle through the header segments in reverse order (to find where to put the APP13 block - after any APP0 to APP12 blocks)

        $i = count( $jpeg_header_data ) - 1;

        while (( $i >= 0 ) && ( ( $jpeg_header_data[$i]['SegType'] > 0xED ) || ( $jpeg_header_data[$i]['SegType'] < 0xE0 ) ) )

        {

                $i--;

        }







        // Cycle through the packed output data until it's size is less than 32000 bytes, outputting each 32000 byte block to an APP13 segment

        while ( strlen( $packed_IRB_data ) > 32000 )

        {

                // Change: Fixed put_Photoshop_IRB to output "Photoshop 3.0\x00" string with every APP13 segment, not just the first one, as of 1.03



                // Write a 32000 byte APP13 segment

                array_splice($jpeg_header_data, $i +1  , 0, array(  "SegType" => 0xED,

                                                                "SegName" => "APP13",

                                                                "SegDesc" => $GLOBALS[ "JPEG_Segment_Descriptions" ][ 0xED ],

                                                                "SegData" => "Photoshop 3.0\x00" . substr( $packed_IRB_data,0,32000) ) );



                // Delete the 32000 bytes from the packed output data, that were just output

                $packed_IRB_data = substr_replace($packed_IRB_data, '', 0, 32000);

                $i++;

        }



        // Write the last block of packed output data to an APP13 segment - Note array_splice doesn't work with multidimensional arrays, hence inserting a blank string

        array_splice($jpeg_header_data, $i + 1 , 0, "" );

        $jpeg_header_data[$i + 1] =  array( "SegType" => 0xED,

                                        "SegName" => "APP13",

                                        "SegDesc" => $GLOBALS[ "JPEG_Segment_Descriptions" ][ 0xED ],

                                        "SegData" => "Photoshop 3.0\x00" . $packed_IRB_data );



        return $jpeg_header_data;

}



/******************************************************************************

* End of Function:     put_Photoshop_IRB

******************************************************************************/

















/******************************************************************************

*

* Function:     get_Photoshop_IPTC

*

* Description:  Retrieves IPTC-NAA IIM information from within a Photoshop

*               IRB (if it is present) and returns it in an array. Uses

*               information supplied by the get_jpeg_header_data function

*

* Parameters:   Photoshop_IRB_data - an array of Photoshop IRB records, as

*                                    returned from get_Photoshop_IRB

*

* Returns:      IPTC_Data_Out - The array of IPTC-NAA IIM records

*               FALSE - if an IPTC-NAA IIM record could not be found, or if

*                       an error occured

*

******************************************************************************/



function get_Photoshop_IPTC( $Photoshop_IRB_data )

{



        // Change: Initialise array correctly, as of revision 1.10

        $IPTC_Data_Out = array();



        //Cycle through the Photoshop 8BIM records looking for the IPTC-NAA record

        for( $i = 0; $i < count( $Photoshop_IRB_data ); $i++ )

        {

                // Check if each record is a IPTC record (which has id 0x0404)

                if ( $Photoshop_IRB_data[$i]['ResID']  == 0x0404 )

                {

                        // We've found an IPTC block - Decode it

                        $IPTC_Data_Out = get_IPTC( $Photoshop_IRB_data[$i]['ResData'] );

                }

        }



        // If there was no records put into the output array,

        if ( count( $IPTC_Data_Out ) == 0 )

        {

                // Then return false

                return FALSE;

        }

        else

        {

                // Otherwise return the array

                return $IPTC_Data_Out;

        }



}

/******************************************************************************

* End of Function:     get_Photoshop_IPTC

******************************************************************************/













/******************************************************************************

*

* Function:     put_Photoshop_IPTC

*

* Description:  Inserts a new IPTC-NAA IIM resource into a Photoshop

*               IRB, or replaces an the existing resource if one is present.

*               Uses information supplied by the get_Photoshop_IRB function

*

* Parameters:   Photoshop_IRB_data - an array of Photoshop IRB records, as

*                                    returned from get_Photoshop_IRB, into

*                                    which the IPTC-NAA IIM record will be inserted

*               new_IPTC_block - an array of IPTC-NAA records in the same format

*                                as those returned by get_Photoshop_IPTC

*

* Returns:      Photoshop_IRB_data - The Photoshop IRB array with the

*                                     IPTC-NAA IIM resource inserted

*

******************************************************************************/



function put_Photoshop_IPTC( $Photoshop_IRB_data, $new_IPTC_block )

{

        $iptc_block_pos = -1;



        //Cycle through the 8BIM records looking for the IPTC-NAA record

        for( $i = 0; $i < count( $Photoshop_IRB_data ); $i++ )

        {

                // Check if each record is a IPTC record (which has id 0x0404)

                if ( $Photoshop_IRB_data[$i]['ResID']  == 0x0404 )

                {

                        // We've found an IPTC block - save the position

                        $iptc_block_pos = $i;

                }

        }



        // If no IPTC block was found, create a new one

        if ( $iptc_block_pos == -1 )

        {

                // New block position will be at the end of the array

                $iptc_block_pos = count( $Photoshop_IRB_data );

        }





        // Write the new IRB resource to the Photoshop IRB array with no data

        $Photoshop_IRB_data[$iptc_block_pos] = array(   "ResID" =>   0x0404,

                                                        "ResName" => $GLOBALS['Photoshop_ID_Names'][ 0x0404 ],

                                                        "ResDesc" => $GLOBALS[ "Photoshop_ID_Descriptions" ][ 0x0404 ],

                                                        "ResEmbeddedName" => "\x00\x00",

                                                        "ResData" => put_IPTC( $new_IPTC_block ) );





        // Return the modified IRB

        return $Photoshop_IRB_data;

}



/******************************************************************************

* End of Function:     put_Photoshop_IPTC

******************************************************************************/

















/******************************************************************************

*

* Function:     Interpret_IRB_to_HTML

*

* Description:  Generates html showing the information contained in a Photoshop

*               IRB data array, as retrieved with get_Photoshop_IRB, including

*               any IPTC-NAA IIM records found.

*

*               Please note that the following resource numbers are not currently

*               decoded: ( Many of these do not apply to JPEG images)

*               0x03E9, 0x03EE, 0x03EF, 0x03F0, 0x03F1, 0x03F2, 0x03F6, 0x03F9,

*               0x03FA, 0x03FB, 0x03FD, 0x03FE, 0x0400, 0x0401, 0x0402, 0x0405,

*               0x040E, 0x040F, 0x0410, 0x0412, 0x0413, 0x0415, 0x0416, 0x0417,

*               0x041B, 0x041C, 0x041D, 0x0BB7

*

*               ( Also these Obsolete resource numbers)

*               0x03E8, 0x03EB, 0x03FC, 0x03FF, 0x0403

*

*

* Parameters:   IRB_array - a Photoshop IRB data array as from get_Photoshop_IRB

*               filename - the name of the JPEG file being processed ( used

*                          by the script which displays the Photoshop thumbnail)

*

*

* Returns:      output_str - the HTML string

*

******************************************************************************/



function Interpret_IRB_to_HTML( $IRB_array, $filename )

{

        // Create a string to receive the HTML

        $output_str = "";



        // Check if the Photoshop IRB array is valid

        if ( $IRB_array !== FALSE )

        {



                // Create another string to receive secondary HTML to be appended at the end

                $secondary_output_str = "";



                // Add the Heading to the HTML

                $output_str .= "<h2 class=\"Photoshop_Main_Heading\">Contains Photoshop Information Resource Block (IRB)</h2>";



                // Add Table to the HTML

                $output_str .= "<table class=\"Photoshop_Table\" border=1>\n";



                // Cycle through each of the Photoshop IRB records, creating HTML for each

                foreach( $IRB_array as $IRB_Resource )

                {

                        // Check if the entry is a known Photoshop IRB resource



                        // Get the Name of the Resource

                        if ( array_key_exists( $IRB_Resource['ResID'], $GLOBALS[ "Photoshop_ID_Names" ] ) )

                        {

                                $Resource_Name = $GLOBALS['Photoshop_ID_Names'][ $IRB_Resource['ResID'] ];

                        }

                        else

                        {

                                // Change: Added check for $GLOBALS['HIDE_UNKNOWN_TAGS'] to allow hiding of unknown resources as of 1.11

                                if ( $GLOBALS['HIDE_UNKNOWN_TAGS'] == TRUE )

                                {

                                        continue;

                                }

                                else

                                {

                                        // Unknown Resource - Make appropriate name

                                        $Resource_Name = "Unknown Resource (". $IRB_Resource['ResID'] .")";

                                }

                        }



                        // Add HTML for the resource as appropriate

                        switch ( $IRB_Resource['ResID'] )

                        {



                                case 0x0404 : // IPTC-NAA IIM Record

                                        $secondary_output_str .= Interpret_IPTC_to_HTML( get_IPTC( $IRB_Resource['ResData'] ) );

                                        break;



                                case 0x040B : // URL

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><a href=\"" . $IRB_Resource['ResData'] . "\">" . htmlentities( $IRB_Resource['ResData'] ) ."</a></td></tr>\n";

                                        break;



                                case 0x040A : // Copyright Marked

                                        if ( hexdec( bin2hex( $IRB_Resource['ResData'] ) ) == 1 )

                                        {

                                                $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Image is Copyrighted Material</pre></td></tr>\n";

                                        }

                                        else

                                        {

                                                $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Image is Not Copyrighted Material</pre></td></tr>\n";

                                        }

                                        break;



                                case 0x040D : // Global Lighting Angle

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Global lighting angle for effects layer = " . hexdec( bin2hex( $IRB_Resource['ResData'] ) ) . " degrees</pre></td></tr>\n";

                                        break;



                                case 0x0419 : // Global Altitude

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Global Altitude = " . hexdec( bin2hex( $IRB_Resource['ResData'] ) ) . "</pre></td></tr>\n";

                                        break;



                                case 0x0421 : // Version Info

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Version = " . hexdec( bin2hex( substr( $IRB_Resource['ResData'], 0, 4 ) ) ) . "\n";

                                        $output_str .= "Has Real Merged Data = " . ord( $IRB_Resource['ResData']{4} ) . "\n";

                                        $writer_size = hexdec( bin2hex( substr( $IRB_Resource['ResData'], 5, 4 ) ) ) * 2;



                                        $output_str .= "Writer Name = " . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], 9, $writer_size ), TRUE ) . "\n";

                                        $reader_size = hexdec( bin2hex( substr( $IRB_Resource['ResData'], 9 + $writer_size , 4 ) ) ) * 2;

                                        $output_str .= "Reader Name = " . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], 13 + $writer_size, $reader_size ), TRUE ) . "\n";

                                        $output_str .= "File Version = " . hexdec( bin2hex( substr( $IRB_Resource['ResData'], 13 + $writer_size + $reader_size, 4 ) ) ) . "\n";

                                        $output_str .=  "</pre></td></tr>\n";

                                        break;



                                case 0x0411 : // ICC Untagged

                                        if ( $IRB_Resource['ResData'] == "\x01" )

                                        {

                                                $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Intentionally untagged - any assumed ICC profile handling disabled</pre></td></tr>\n";

                                        }

                                        else

                                        {

                                                $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>Unknown value (0x" .bin2hex( $IRB_Resource['ResData'] ). ")</pre></td></tr>\n";

                                        }

                                        break;



                                case 0x041A : // Slices

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\">";



                                        // Unpack the first 24 bytes

                                        $Slices_Info = unpack("NVersion/NBound_top/NBound_left/NBound_bottom/NBound_right/NStringlen", $IRB_Resource['ResData'] );

                                        $output_str .= "Version = " . $Slices_Info['Version'] . "<br>\n";

                                        $output_str .= "Bounding Rectangle =  Top:" . $Slices_Info['Bound_top'] . ", Left:" . $Slices_Info['Bound_left'] . ", Bottom:" . $Slices_Info['Bound_bottom'] . ", Right:" . $Slices_Info['Bound_right'] . " (Pixels)<br>\n";

                                        $Slicepos = 24;



                                        // Extract a Unicode String

                                        $output_str .= "Text = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], 24, $Slices_Info['Stringlen']*2), TRUE ) . "'<br>\n";

                                        $Slicepos += $Slices_Info['Stringlen'] * 2;



                                        // Unpack the number of Slices

                                        $Num_Slices = hexdec( bin2hex( substr( $IRB_Resource['ResData'], $Slicepos, 4 ) ) );

                                        $output_str .= "Number of Slices = " . $Num_Slices . "\n";

                                        $Slicepos += 4;



                                        // Cycle through the slices

                                        for( $i = 1; $i <= $Num_Slices; $i++ )

                                        {

                                                $output_str .= "<br><br>Slice $i:<br>\n";



                                                // Unpack the first 16 bytes of the slice

                                                $SliceA = unpack("NID/NGroupID/NOrigin/NStringlen", substr($IRB_Resource['ResData'], $Slicepos ) );

                                                $Slicepos += 16;

                                                $output_str .= "ID = " . $SliceA['ID'] . "<br>\n";

                                                $output_str .= "Group ID = " . $SliceA['GroupID'] . "<br>\n";

                                                $output_str .= "Origin = " . $SliceA['Origin'] . "<br>\n";



                                                // Extract a Unicode String

                                                $output_str .= "Text = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $SliceA['Stringlen']*2), TRUE ) . "'<br>\n";

                                                $Slicepos += $SliceA['Stringlen'] * 2;



                                                // Unpack the next 24 bytes of the slice

                                                $SliceB = unpack("NType/NLeftPos/NTopPos/NRightPos/NBottomPos/NURLlen", substr($IRB_Resource['ResData'], $Slicepos )  );

                                                $Slicepos += 24;

                                                $output_str .= "Type = " . $SliceB['Type'] . "<br>\n";

                                                $output_str .= "Position =  Top:" . $SliceB['TopPos'] . ", Left:" . $SliceB['LeftPos'] . ", Bottom:" . $SliceB['BottomPos'] . ", Right:" . $SliceB['RightPos'] . " (Pixels)<br>\n";



                                                // Extract a Unicode String

                                                $output_str .= "URL = <a href='" . substr( $IRB_Resource['ResData'], $Slicepos, $SliceB['URLlen']*2) . "'>" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $SliceB['URLlen']*2), TRUE ) . "</a><br>\n";

                                                $Slicepos += $SliceB['URLlen'] * 2;



                                                // Unpack the length of a Unicode String

                                                $Targetlen = hexdec( bin2hex( substr( $IRB_Resource['ResData'], $Slicepos, 4 ) ) );

                                                $Slicepos += 4;

                                                // Extract a Unicode String

                                                $output_str .= "Target = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $Targetlen*2), TRUE ) . "'<br>\n";

                                                $Slicepos += $Targetlen * 2;



                                                // Unpack the length of a Unicode String

                                                $Messagelen = hexdec( bin2hex( substr( $IRB_Resource['ResData'], $Slicepos, 4 ) ) );

                                                $Slicepos += 4;

                                                // Extract a Unicode String

                                                $output_str .= "Message = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $Messagelen*2), TRUE ) . "'<br>\n";

                                                $Slicepos += $Messagelen * 2;



                                                // Unpack the length of a Unicode String

                                                $AltTaglen = hexdec( bin2hex( substr( $IRB_Resource['ResData'], $Slicepos, 4 ) ) );

                                                $Slicepos += 4;

                                                // Extract a Unicode String

                                                $output_str .= "Alt Tag = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $AltTaglen*2), TRUE ) . "'<br>\n";

                                                $Slicepos += $AltTaglen * 2;



                                                // Unpack the HTML flag

                                                if ( ord( $IRB_Resource['ResData']{ $Slicepos } ) === 0x01 )

                                                {

                                                        $output_str .= "Cell Text is HTML<br>\n";

                                                }

                                                else

                                                {

                                                        $output_str .= "Cell Text is NOT HTML<br>\n";

                                                }

                                                $Slicepos++;



                                                // Unpack the length of a Unicode String

                                                $CellTextlen = hexdec( bin2hex( substr( $IRB_Resource['ResData'], $Slicepos, 4 ) ) );

                                                $Slicepos += 4;

                                                // Extract a Unicode String

                                                $output_str .= "Cell Text = '" . HTML_UTF16_Escape( substr( $IRB_Resource['ResData'], $Slicepos, $CellTextlen*2), TRUE ) . "'<br>\n";

                                                $Slicepos += $CellTextlen * 2;





                                                // Unpack the last 12 bytes of the slice

                                                $SliceC = unpack("NAlignH/NAlignV/CAlpha/CRed/CGreen/CBlue", substr($IRB_Resource['ResData'], $Slicepos )  );

                                                $Slicepos += 12;

                                                $output_str .= "Alignment =  Horizontal:" . $SliceC['AlignH'] . ", Vertical:" . $SliceC['AlignV'] . "<br>\n";

                                                $output_str .= "Alpha Colour = " . $SliceC['Alpha'] . "<br>\n";

                                                $output_str .= "Red = " . $SliceC['Red'] . "<br>\n";

                                                $output_str .= "Green = " . $SliceC['Green'] . "<br>\n";

                                                $output_str .= "Blue = " . $SliceC['Blue'] . "\n";

                                        }



                                        $output_str .= "</td></tr>\n";



                                        break;





                                case 0x0408 : // Grid and Guides information

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\">";



                                        // Unpack the Grids info

                                        $Grid_Info = unpack("NVersion/NGridCycleH/NGridCycleV/NGuideCount", $IRB_Resource['ResData'] );

                                        $output_str .= "Version = " . $Grid_Info['Version'] . "<br>\n";

                                        $output_str .= "Grid Cycle = " . $Grid_Info['GridCycleH']/32 . " Pixel(s)  x  " . $Grid_Info['GridCycleV']/32 . " Pixel(s)<br>\n";

                                        $output_str .= "Number of Guides = " . $Grid_Info['GuideCount'] . "\n";



                                        // Cycle through the Guides

                                        for( $i = 0; $i < $Grid_Info['GuideCount']; $i++ )

                                        {

                                                // Unpack the info for this guide

                                                $Guide_Info = unpack("NLocation/CDirection", substr($IRB_Resource['ResData'],16+$i*5,5) );

                                                $output_str .= "<br>Guide $i : Location = " . $Guide_Info['Location']/32 . " Pixel(s) from edge";

                                                if ( $Guide_Info['Direction'] === 0 )

                                                {

                                                        $output_str .= ", Vertical\n";

                                                }

                                                else

                                                {

                                                        $output_str .= ", Horizontal\n";

                                                }

                                        }

                                        break;

                                        $output_str .= "</td></tr>\n";



                                case 0x0406 : // JPEG Quality

                                        $Qual_Info = unpack("nQuality/nFormat/nScans/Cconst", $IRB_Resource['ResData'] );

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\">";

                                        switch ( $Qual_Info['Quality'] )

                                        {

                                                case 0xFFFD:

                                                        $output_str .= "Quality 1 (Low)<br>\n";

                                                        break;

                                                case 0xFFFE:

                                                        $output_str .= "Quality 2 (Low)<br>\n";

                                                        break;

                                                case 0xFFFF:

                                                        $output_str .= "Quality 3 (Low)<br>\n";

                                                        break;

                                                case 0x0000:

                                                        $output_str .= "Quality 4 (Low)<br>\n";

                                                        break;

                                                case 0x0001:

                                                        $output_str .= "Quality 5 (Medium)<br>\n";

                                                        break;

                                                case 0x0002:

                                                        $output_str .= "Quality 6 (Medium)<br>\n";

                                                        break;

                                                case 0x0003:

                                                        $output_str .= "Quality 7 (Medium)<br>\n";

                                                        break;

                                                case 0x0004:

                                                        $output_str .= "Quality 8 (High)<br>\n";

                                                        break;

                                                case 0x0005:

                                                        $output_str .= "Quality 9 (High)<br>\n";

                                                        break;

                                                case 0x0006:

                                                        $output_str .= "Quality 10 (Maximum)<br>\n";

                                                        break;

                                                case 0x0007:

                                                        $output_str .= "Quality 11 (Maximum)<br>\n";

                                                        break;

                                                case 0x0008:

                                                        $output_str .= "Quality 12 (Maximum)<br>\n";

                                                        break;

                                                default:

                                                        $output_str .= "Unknown Quality (" . $Qual_Info['Quality'] . ")<br>\n";

                                                        break;

                                        }



                                        switch ( $Qual_Info['Format'] )

                                        {

                                                case 0x0000:

                                                        $output_str .= "Standard Format\n";

                                                        break;

                                                case 0x0001:

                                                        $output_str .= "Optimised Format\n";

                                                        break;

                                                case 0x0101:

                                                        $output_str .= "Progressive Format<br>\n";

                                                        break;

                                                default:

                                                        $output_str .= "Unknown Format (" . $Qual_Info['Format'] .")\n";

                                                        break;

                                        }

                                        if ( $Qual_Info['Format'] == 0x0101 )

                                        {

                                                switch ( $Qual_Info['Scans'] )

                                                {

                                                        case 0x0001:

                                                                $output_str .= "3 Scans\n";

                                                                break;

                                                        case 0x0002:

                                                                $output_str .= "4 Scans\n";

                                                                break;

                                                        case 0x0003:

                                                                $output_str .= "5 Scans\n";

                                                                break;

                                                        default:

                                                                $output_str .= "Unknown number of scans (" . $Qual_Info['Scans'] .")\n";

                                                                break;

                                                }

                                        }

                                        $output_str .= "</td></tr>\n";

                                        break;



                                case 0x0409 : // Thumbnail Resource

                                case 0x040C : // Thumbnail Resource

                                        $thumb_data = unpack("NFormat/NWidth/NHeight/NWidthBytes/NSize/NCompressedSize/nBitsPixel/nPlanes", $IRB_Resource['ResData'] );

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Format = " . (( $thumb_data['Format'] == 1 ) ? "JPEG RGB\n" :  "Raw RGB\n");

                                        $output_str .= "Width = " . $thumb_data['Width'] . "\n";

                                        $output_str .= "Height = " . $thumb_data['Height'] . "\n";

                                        $output_str .= "Padded Row Bytes = " . $thumb_data['WidthBytes'] . " bytes\n";

                                        $output_str .= "Total Size = " . $thumb_data['Size'] . " bytes\n";

                                        $output_str .= "Compressed Size = " . $thumb_data['CompressedSize'] . " bytes\n";

                                        $output_str .= "Bits per Pixel = " . $thumb_data['BitsPixel'] . " bits\n";

                                        $output_str .= "Number of planes = " . $thumb_data['Planes'] . " bytes\n";



                                        // Change: as of version 1.11 - Changed to make thumbnail link portable across directories

                                        // Build the path of the thumbnail script and its filename parameter to put in a url

                                        $link_str = get_relative_path( dirname(__FILE__) . "/get_ps_thumb.php" , getcwd ( ) );

                                        $link_str .= "?filename=";

                                        $link_str .= get_relative_path( $filename, dirname(__FILE__) );



                                        // Add thumbnail link to html

                                        $output_str .= "Thumbnail Data:</pre><a class=\"Photoshop_Thumbnail_Link\" href=\"$link_str\"><img class=\"Photoshop_Thumbnail_Link\" src=\"$link_str\"></a>\n";



                                        $output_str .=  "</td></tr>\n";

                                        break;



                                case 0x0414 : // Document Specific ID's

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>" . hexdec( bin2hex( $IRB_Resource['ResData'] ) ) . "</pre></td></tr>\n";

                                        break;



                                case 0x041E : // URL List

                                        $URL_count = hexdec( bin2hex( substr( $IRB_Resource['ResData'], 0, 4 ) ) );

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\">\n";

                                        $output_str .= "$URL_count URL's in list<br>\n";

                                        $urlstr = substr( $IRB_Resource['ResData'], 4 );

                                        // TODO: Check if URL List in Photoshop IRB works

                                        for( $i = 0; $i < $URL_count; $i++ )

                                        {

                                                $url_data = unpack( "NLong/NID/NURLSize", $urlstr );

                                                $output_str .= "URL $i info: long = " . $url_data['Long'] .", ";

                                                $output_str .= "ID = " . $url_data['ID'] . ", ";

                                                $urlstr = substr( $urlstr, 12 );

                                                $url = substr( $urlstr, 0, $url_data['URLSize'] );

                                                $output_str .= "URL = <a href=\"" . xml_UTF16_clean( $url, TRUE ) . "\">" . HTML_UTF16_Escape( $url, TRUE ) . "</a><br>\n";

                                        }

                                        $output_str .= "</td></tr>\n";

                                        break;

                                case 0x03F4 : // Grayscale and multichannel halftoning information.

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= Interpret_Halftone( $IRB_Resource['ResData'] );

                                        $output_str .= "</pre></td></tr>\n";

                                        break;

                                case 0x03F5 : // Color halftoning information

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Cyan Halftoning Info:\n" . Interpret_Halftone( substr( $IRB_Resource['ResData'], 0, 18 ) ) . "\n\n";

                                        $output_str .= "Magenta Halftoning Info:\n" . Interpret_Halftone( substr( $IRB_Resource['ResData'], 18, 18 ) ) . "\n\n";

                                        $output_str .= "Yellow Halftoning Info:\n" . Interpret_Halftone( substr( $IRB_Resource['ResData'], 36, 18 ) ) . "\n";

                                        $output_str .= "Black Halftoning Info:\n" . Interpret_Halftone( substr( $IRB_Resource['ResData'], 54, 18 ) ) . "\n";

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                case 0x03F7 : // Grayscale and multichannel transfer function.

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= Interpret_Transfer_Function( substr( $IRB_Resource['ResData'], 0, 28 ) ) ;

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                case 0x03F8 : // Color transfer functions

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Red Transfer Function:   \n" . Interpret_Transfer_Function( substr( $IRB_Resource['ResData'], 0, 28 ) ) . "\n\n";

                                        $output_str .= "Green Transfer Function: \n" . Interpret_Transfer_Function( substr( $IRB_Resource['ResData'], 28, 28 ) ) . "\n\n";

                                        $output_str .= "Blue Transfer Function:  \n" . Interpret_Transfer_Function( substr( $IRB_Resource['ResData'], 56, 28 ) ) . "\n";

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                case 0x03F3 : // Print Flags

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        if ( $IRB_Resource['ResData']{0} == "\x01" )

                                        {

                                                $output_str .= "Labels Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Labels Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{1} == "\x01" )

                                        {

                                                $output_str .= "Crop Marks Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Crop Marks Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{2} == "\x01" )

                                        {

                                                $output_str .= "Color Bars Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Color Bars Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{3} == "\x01" )

                                        {

                                                $output_str .= "Registration Marks Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Registration Marks Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{4} == "\x01" )

                                        {

                                                $output_str .= "Negative Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Negative Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{5} == "\x01" )

                                        {

                                                $output_str .= "Flip Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Flip Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{6} == "\x01" )

                                        {

                                                $output_str .= "Interpolate Selected\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Interpolate Not Selected\n";

                                        }

                                        if ( $IRB_Resource['ResData']{7} == "\x01" )

                                        {

                                                $output_str .= "Caption Selected";

                                        }

                                        else

                                        {

                                                $output_str .= "Caption Not Selected";

                                        }

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                case 0x2710 : // Print Flags Information

                                        $PrintFlags = unpack( "nVersion/CCentCrop/Cjunk/NBleedWidth/nBleedWidthScale", $IRB_Resource['ResData'] );

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Version = " . $PrintFlags['Version'] . "\n";

                                        $output_str .= "Centre Crop Marks = " . $PrintFlags['CentCrop'] . "\n";

                                        $output_str .= "Bleed Width = " . $PrintFlags['BleedWidth'] . "\n";

                                        $output_str .= "Bleed Width Scale = " . $PrintFlags['BleedWidthScale'];

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                case 0x03ED : // Resolution Info

                                        $ResInfo = unpack( "nhRes_int/nhResdec/nhResUnit/nwidthUnit/nvRes_int/nvResdec/nvResUnit/nheightUnit", $IRB_Resource['ResData'] );

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\"><pre>\n";

                                        $output_str .= "Horizontal Resolution = " . ($ResInfo['hRes_int'] + $ResInfo['hResdec']/65536) . " pixels per Inch\n";

                                        $output_str .= "Vertical Resolution = " . ($ResInfo['vRes_int'] + $ResInfo['vResdec']/65536) . " pixels per Inch\n";

                                        if ( $ResInfo['hResUnit'] == 1 )

                                        {

                                                $output_str .= "Display units for Horizontal Resolution = Pixels per Inch\n";

                                        }

                                        elseif ( $ResInfo['hResUnit'] == 2 )

                                        {

                                                $output_str .= "Display units for Horizontal Resolution = Pixels per Centimetre\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Display units for Horizontal Resolution = Unknown Value (". $ResInfo['hResUnit'] .")\n";

                                        }



                                        if ( $ResInfo['vResUnit'] == 1 )

                                        {

                                                $output_str .= "Display units for Vertical Resolution = Pixels per Inch\n";

                                        }

                                        elseif ( $ResInfo['vResUnit'] == 2 )

                                        {

                                                $output_str .= "Display units for Vertical Resolution = Pixels per Centimetre\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Display units for Vertical Resolution = Unknown Value (". $ResInfo['vResUnit'] .")\n";

                                        }



                                        if ( $ResInfo['widthUnit'] == 1 )

                                        {

                                                $output_str .= "Display units for Image Width = Inches\n";

                                        }

                                        elseif ( $ResInfo['widthUnit'] == 2 )

                                        {

                                                $output_str .= "Display units for Image Width = Centimetres\n";

                                        }

                                        elseif ( $ResInfo['widthUnit'] == 3 )

                                        {

                                                $output_str .= "Display units for Image Width = Points\n";

                                        }

                                        elseif ( $ResInfo['widthUnit'] == 4 )

                                        {

                                                $output_str .= "Display units for Image Width = Picas\n";

                                        }

                                        elseif ( $ResInfo['widthUnit'] == 5 )

                                        {

                                                $output_str .= "Display units for Image Width = Columns\n";

                                        }

                                        else

                                        {

                                                $output_str .= "Display units for Image Width = Unknown Value (". $ResInfo['widthUnit'] .")\n";

                                        }



                                        if ( $ResInfo['heightUnit'] == 1 )

                                        {

                                                $output_str .= "Display units for Image Height = Inches";

                                        }

                                        elseif ( $ResInfo['heightUnit'] == 2 )

                                        {

                                                $output_str .= "Display units for Image Height = Centimetres";

                                        }

                                        elseif ( $ResInfo['heightUnit'] == 3 )

                                        {

                                                $output_str .= "Display units for Image Height = Points";

                                        }

                                        elseif ( $ResInfo['heightUnit'] == 4 )

                                        {

                                                $output_str .= "Display units for Image Height = Picas";

                                        }

                                        elseif ( $ResInfo['heightUnit'] == 5 )

                                        {

                                                $output_str .= "Display units for Image Height = Columns";

                                        }

                                        else

                                        {

                                                $output_str .= "Display units for Image Height = Unknown Value (". $ResInfo['heightUnit'] .")";

                                        }

                                        $output_str .= "</pre></td></tr>\n";

                                        break;



                                default : // All other records

                                        $output_str .= "<tr class=\"Photoshop_Table_Row\"><td class=\"Photoshop_Caption_Cell\">$Resource_Name</td><td class=\"Photoshop_Value_Cell\">RESOURCE DECODING NOT IMPLEMENTED YET<BR>" . strlen( $IRB_Resource['ResData'] ) . " bytes</td></tr>\n";



                        }



                }



                // Add the table end to the HTML

                $output_str .= "</table>\n";



                // Add any secondary output to the HTML

                $output_str .= $secondary_output_str;



        }



        // Return the HTML

        return $output_str;

}



/******************************************************************************

* End of Function:     Interpret_IRB_to_HTML

******************************************************************************/













/******************************************************************************

*

*         INTERNAL FUNCTIONS

*

******************************************************************************/















/******************************************************************************

*

* Function:     unpack_Photoshop_IRB_Data

*

* Description:  Extracts Photoshop Information Resource Block (IRB) information

*               from a binary string containing the IRB, as read from a file

*

* Parameters:   IRB_Data - The binary string containing the IRB

*

* Returns:      IRBdata - The array of Photoshop IRB records

*

******************************************************************************/



function unpack_Photoshop_IRB_Data( $IRB_Data )

{

        $pos = 0;



        // Cycle through the IRB and extract its records - Records are started with 8BIM, so cycle until no more instances of 8BIM can be found

        while ( ( $pos < strlen( $IRB_Data ) ) && ( ($pos = strpos( $IRB_Data, "8BIM", $pos) ) !== FALSE ) )

        {

                // Skip the position over the 8BIM characters

                $pos += 4;



                // Next two characters are the record ID - denoting what type of record it is.

                $ID = ord( $IRB_Data{ $pos } ) * 256 + ord( $IRB_Data{ $pos +1 } );



                // Skip the positionover the two record ID characters

                $pos += 2;



                // Next comes a Record Name - usually not used, but it should be a null terminated string, padded with 0x00 to be an even length

                $namestartpos = $pos;



                // Change: Fixed processing of embedded resource names, as of revision 1.10



                // NOTE: Photoshop does not process resource names according to the standard :

                // "Adobe Photoshop 6.0 File Formats Specification, Version 6.0, Release 2, November 2000"

                //

                // The resource name is actually formatted as follows:

                // One byte name length, followed by the null terminated ascii name string.

                // The field is then padded with a Null character if required, to ensure that the

                // total length of the name length and name is even.



                // Name - process it

                // Get the length

                $namelen = ord ( $IRB_Data{ $namestartpos } );



                // Total length of name and length info must be even, hence name length must be odd

                // Check if the name length is even,

                if ( $namelen % 2 == 0 )

                {

                        // add one to length to make it odd

                        $namelen ++;

                }

                // Extract the name

                $resembeddedname = trim( substr ( $IRB_Data, $namestartpos+1,  $namelen) );

                $pos += $namelen + 1;





                // Next is a four byte size field indicating the size in bytes of the record's data  - MSB first

                $datasize =     ord( $IRB_Data{ $pos } ) * 16777216 + ord( $IRB_Data{ $pos + 1 } ) * 65536 +

                                ord( $IRB_Data{ $pos + 2 } ) * 256 + ord( $IRB_Data{ $pos + 3 } );

                $pos += 4;



                // The record is stored padded with 0x00 characters to make the size even, so we need to calculate the stored size

                $storedsize =  $datasize + ($datasize % 2);



                $resdata = substr ( $IRB_Data, $pos, $datasize );



                // Get the description for this resource

                // Check if this is a Path information Resource, since they have a range of ID's

                if ( ( $ID >= 0x07D0 ) && ( $ID <= 0x0BB6 ) )

                {

                        $ResDesc = "ID Info : Path Information (saved paths).";

                }

                else

                {

                        if ( array_key_exists( $ID, $GLOBALS[ "Photoshop_ID_Descriptions" ] ) )

                        {

                                $ResDesc = $GLOBALS[ "Photoshop_ID_Descriptions" ][ $ID ];

                        }

                        else

                        {

                                $ResDesc = "";

                        }

                }



                // Get the Name of the Resource

                if ( array_key_exists( $ID, $GLOBALS[ "Photoshop_ID_Names" ] ) )

                {

                        $ResName = $GLOBALS['Photoshop_ID_Names'][ $ID ];

                }

                else

                {

                        $ResName = "";

                }





                // Store the Resource in the array to be returned



                $IRB_Array[] = array(     "ResID" => $ID,

                                        "ResName" => $ResName,

                                        "ResDesc" => $ResDesc,

                                        "ResEmbeddedName" => $resembeddedname,

                                        "ResData" => $resdata );



                // Jump over the data to the next record

                $pos += $storedsize;

        }



        // Return the array created

        return $IRB_Array;

}



/******************************************************************************

* End of Function:     unpack_Photoshop_IRB_Data

******************************************************************************/























/******************************************************************************

*

* Function:     pack_Photoshop_IRB_Data

*

* Description:  Packs a Photoshop Information Resource Block (IRB) array into it's

*               binary form, which can be written to a file

*

* Parameters:   IRB_data - an Photoshop IRB array to be converted. Should be in

*                          the same format as received from get_Photoshop_IRB

*

* Returns:      packed_IRB_data - the binary string of packed IRB data

*

******************************************************************************/



function pack_Photoshop_IRB_Data( $IRB_data )

{

        $packed_IRB_data = "";



        // Cycle through each resource in the IRB,

        foreach ($IRB_data as $resource)

        {



                // Change: Fix to avoid creating blank resources, as of revision 1.10



                // Check if there is actually any data for this resource

                if( strlen( $resource['ResData'] ) == 0 )

                {

                        // No data for resource - skip it

                        continue;

                }



                // Append the 8BIM tag, and resource ID to the packed output data

                $packed_IRB_data .= pack("a4n", "8BIM", $resource['ResID'] );





                // Change: Fixed processing of embedded resource names, as of revision 1.10



                // NOTE: Photoshop does not process resource names according to the standard :

                // "Adobe Photoshop 6.0 File Formats Specification, Version 6.0, Release 2, November 2000"

                //

                // The resource name is actually formatted as follows:

                // One byte name length, followed by the null terminated ascii name string.

                // The field is then padded with a Null character if required, to ensure that the

                // total length of the name length and name is even.



                // Append Name Size

                $packed_IRB_data .= pack( "c", strlen(trim($resource['ResEmbeddedName'])));



                // Append the Resource Name to the packed output data

                $packed_IRB_data .= trim($resource['ResEmbeddedName']);



                // If the resource name is even length, then with the addition of

                // the size it becomes odd and needs to be padded to an even number

                if ( strlen( trim($resource['ResEmbeddedName']) ) % 2 == 0 )

                {

                        // then it needs to be evened up by appending another null

                        $packed_IRB_data .= "\x00";

                }



                // Append the resource data size to the packed output data

                $packed_IRB_data .= pack("N", strlen( $resource['ResData'] ) );



                // Append the resource data to the packed output data

                $packed_IRB_data .= $resource['ResData'];



                // If the resource data is odd length,

                if ( strlen( $resource['ResData'] ) % 2 == 1 )

                {

                        // then it needs to be evened up by appending another null

                        $packed_IRB_data .= "\x00";

                }

        }



        // Return the packed data string

        return $packed_IRB_data;

}



/******************************************************************************

* End of Function:     pack_Photoshop_IRB_Data

******************************************************************************/

















/******************************************************************************

*

* Internal Function:     Interpret_Transfer_Function

*

* Description:  Used by Interpret_IRB_to_HTML to interpret Color transfer functions

*               for Photoshop IRB resource 0x03F8. Converts the transfer function

*               information to a human readable version.

*

* Parameters:   Transfer_Function_Binary - a 28 byte Ink curves structure string

*

* Returns:      output_str - the text string containing the transfer function

*                            information

*

******************************************************************************/



function Interpret_Transfer_Function( $Transfer_Function_Binary )

{

        // Unpack the Transfer function information

        $Trans_vals = unpack ( "n13Curve/nOverride",  $Transfer_Function_Binary );



        $output_str = "Transfer Function Points: ";



        // Cycle through each of the Transfer function array values

        foreach ( $Trans_vals as $Key => $val )

        {

                // Check if the value should be negative

                if ($val > 32768 )

                {

                        // Value should be negative - make it so

                        $val = $val - 65536;

                }

                // Check that the Override item is not getting in this list, and

                // that the value is not -1, which means ignored

                if ( ( $Key != "Override" ) && ( $val != -1 ) )

                {

                        // This is a valid transfer function point, output it

                        $output_str .= $val/10 . "%, ";

                }

        }



        // Output the override info

        if ( $Trans_vals['Override'] == 0 )

        {

                $output_str .= "\nOverride: Let printer supply curve";

        }

        else

        {

                $output_str .= "\nOverride: Override printer’s default transfer curve";

        }



        // Return the result

        return $output_str;

}



/******************************************************************************

* End of Function:     Interpret_Transfer_Function

******************************************************************************/











/******************************************************************************

*

* Internal Function:     Interpret_Halftone

*

* Description:  Used by Interpret_IRB_to_HTML to interpret Color halftoning information

*               for Photoshop IRB resource 0x03F5. Converts the halftoning info

*               to a human readable version.

*

* Parameters:   Transfer_Function_Binary - a 18 byte Halftone screen parameter

&                                          structure string

*

* Returns:      output_str - the text string containing the transfer function

*                            information

*

******************************************************************************/



function Interpret_Halftone( $Halftone_Binary )

{

        // Create a string to receive the output

        $output_str = "";



        // Unpack the binary data into an array

        $HalftoneInfo = unpack( "nFreqVal_int/nFreqVal_dec/nFreqScale/nAngle_int/nAngle_dec/nShapeCode/NMisc/CAccurate/CDefault", $Halftone_Binary );



        // Interpret Ink Screen Frequency

        $output_str .= "Ink Screen Frequency = " . ($HalftoneInfo['FreqVal_int'] + $HalftoneInfo['FreqVal_dec']/65536) . " lines per Inch\n";

        if ( $HalftoneInfo['FreqScale'] == 1 )

        {

                $output_str .= "Display units for Ink Screen Frequency = Inches\n";

        }

        else

        {

                $output_str .= "Display units for Ink Screen Frequency = Centimetres\n";

        }



        // Interpret Angle for screen

        $output_str .= "Angle for screen = " . ($HalftoneInfo['Angle_int'] + $HalftoneInfo['Angle_dec']/65536) . " degrees\n";



        // Interpret Shape of Halftone Dots

        if ($HalftoneInfo['ShapeCode'] > 32768 )

        {

                $HalftoneInfo['ShapeCode'] = $HalftoneInfo['ShapeCode'] - 65536;

        }

        if ( $HalftoneInfo['ShapeCode'] == 0 )

        {

                $output_str .= "Shape of Halftone Dots = Round\n";

        }

        elseif ( $HalftoneInfo['ShapeCode'] == 1 )

        {

                $output_str .= "Shape of Halftone Dots = Ellipse\n";

        }

        elseif ( $HalftoneInfo['ShapeCode'] == 2 )

        {

                $output_str .= "Shape of Halftone Dots = Line\n";

        }

        elseif ( $HalftoneInfo['ShapeCode'] == 3 )

        {

                $output_str .= "Shape of Halftone Dots = Square\n";

        }

        elseif ( $HalftoneInfo['ShapeCode'] == 4 )

        {

                $output_str .= "Shape of Halftone Dots = Cross\n";

        }

        elseif ( $HalftoneInfo['ShapeCode'] == 6 )

        {

                $output_str .= "Shape of Halftone Dots = Diamond\n";

        }

        else

        {

                $output_str .= "Shape of Halftone Dots = Unknown shape (" . $HalftoneInfo['ShapeCode'] . ")\n";

        }



        // Interpret Accurate Screens

        if ( $HalftoneInfo['Accurate'] == 1 )

        {

                $output_str .= "Use Accurate Screens Selected\n";

        }

        else

        {

                $output_str .= "Use Other (not Accurate) Screens Selected\n";

        }



        // Interpret Printer Default Screens

        if ( $HalftoneInfo['Default'] == 1 )

        {

                $output_str .= "Use printer’s default screens\n";

        }

        else

        {

                $output_str .= "Use Other (not Printer Default) Screens Selected\n";

        }



        // Return Text

        return $output_str;



}



/******************************************************************************

* End of Global Variable:     Interpret_Halftone

******************************************************************************/

























/******************************************************************************

* Global Variable:      Photoshop_ID_Names

*

* Contents:     The Names of the Photoshop IRB resources, indexed by their

*               resource number

*

******************************************************************************/



$GLOBALS[ "Photoshop_ID_Names" ] = array(

0x03E8 => "Number of channels, rows, columns, depth, and mode. (Obsolete)",

0x03E9 => "Macintosh print manager info ",

0x03EB => "Indexed color table (Obsolete)",

0x03ED => "Resolution Info",

0x03EE => "Alpha Channel Names",

0x03EF => "Display Info",

0x03F0 => "Caption String",

0x03F1 => "Border information",

0x03F2 => "Background color",

0x03F3 => "Print flags",

0x03F4 => "Grayscale and multichannel halftoning information",

0x03F5 => "Color halftoning information",

0x03F6 => "Duotone halftoning information",

0x03F7 => "Grayscale and multichannel transfer function",

0x03F8 => "Color transfer functions",

0x03F9 => "Duotone transfer functions",

0x03FA => "Duotone image information",

0x03FB => "Black and white values",

0x03FC => "Obsolete Resource.",

0x03FD => "EPS options",

0x03FE => "Quick Mask information",

0x03FF => "Obsolete Resource",

0x0400 => "Layer state information",

0x0401 => "Working path (not saved)",

0x0402 => "Layers group information",

0x0403 => "Obsolete Resource",

0x0404 => "IPTC-NAA record",

0x0405 => "Raw Format Image mode",

0x0406 => "JPEG quality",

0x0408 => "Grid and guides information",

0x0409 => "Thumbnail resource",

0x040A => "Copyright flag",

0x040B => "URL",

0x040C => "Thumbnail resource",

0x040D => "Global Angle",

0x040E => "Color samplers resource",

0x040F => "ICC Profile",

0x0410 => "Watermark",

0x0411 => "ICC Untagged",

0x0412 => "Effects visible",

0x0413 => "Spot Halftone",

0x0414 => "Document Specific IDs",

0x0415 => "Unicode Alpha Names",

0x0416 => "Indexed Color Table Count",

0x0417 => "Tansparent Index. Index of transparent color, if any.",

0x0419 => "Global Altitude",

0x041A => "Slices",

0x041B => "Workflow URL",

0x041C => "Jump To XPEP",

0x041D => "Alpha Identifiers",

0x041E => "URL List",

0x0421 => "Version Info",

0x0BB7 => "Name of clipping path.",

0x2710 => "Print flags information"

);



/******************************************************************************

* End of Global Variable:     Photoshop_ID_Names

******************************************************************************/











/******************************************************************************

* Global Variable:      Photoshop_ID_Descriptions

*

* Contents:     The Descriptions of the Photoshop IRB resources, indexed by their

*               resource number

*

******************************************************************************/



$GLOBALS[ "Photoshop_ID_Descriptions" ] = array(

0x03E8 => "Obsolete—Photoshop 2.0 only. number of channels, rows, columns, depth, and mode.",

0x03E9 => "Optional. Macintosh print manager print info record.",

0x03EB => "Obsolete—Photoshop 2.0 only. Contains the indexed color table.",

0x03ED => "ResolutionInfo structure. See Appendix A in Photoshop SDK Guide.pdf",

0x03EE => "Names of the alpha channels as a series of Pascal strings.",

0x03EF => "DisplayInfo structure. See Appendix A in Photoshop SDK Guide.pdf",

0x03F0 => "Optional. The caption as a Pascal string.",

0x03F1 => "Border information. border width, border units",

0x03F2 => "Background color.",

0x03F3 => "Print flags. labels, crop marks, color bars, registration marks, negative, flip, interpolate, caption.",

0x03F4 => "Grayscale and multichannel halftoning information.",

0x03F5 => "Color halftoning information.",

0x03F6 => "Duotone halftoning information.",

0x03F7 => "Grayscale and multichannel transfer function.",

0x03F8 => "Color transfer functions.",

0x03F9 => "Duotone transfer functions.",

0x03FA => "Duotone image information.",

0x03FB => "Effective black and white values for the dot range.",

0x03FC => "Obsolete Resource.",

0x03FD => "EPS options.",

0x03FE => "Quick Mask information. Quick Mask channel ID, Mask initially empty.",

0x03FF => "Obsolete Resource.",

0x0400 => "Layer state information. Index of target layer.",

0x0401 => "Working path (not saved).",

0x0402 => "Layers group information. Group ID for the dragging groups. Layers in a group have the same group ID.",

0x0403 => "Obsolete Resource.",

0x0404 => "IPTC-NAA record. This contains the File Info... information. See the IIMV4.pdf document.",

0x0405 => "Image mode for raw format files.",

0x0406 => "JPEG quality. Private.",

0x0408 => "Grid and guides information.",

0x0409 => "Thumbnail resource.",

0x040A => "Copyright flag. Boolean indicating whether image is copyrighted. Can be set via Property suite or by user in File Info...",

0x040B => "URL. Handle of a text string with uniform resource locator. Can be set via Property suite or by user in File Info...",

0x040C => "Thumbnail resource.",

0x040D => "Global Angle. Global lighting angle for effects layer.",

0x040E => "Color samplers resource.",

0x040F => "ICC Profile. The raw bytes of an ICC format profile, see the ICC34.pdf and ICC34.h files from the Internation Color Consortium.",

0x0410 => "Watermark.",

0x0411 => "ICC Untagged. Disables any assumed profile handling when opening the file. 1 = intentionally untagged.",

0x0412 => "Effects visible. Show/hide all the effects layer.",

0x0413 => "Spot Halftone. Version, length, variable length data.",

0x0414 => "Document specific IDs for layer identification",

0x0415 => "Unicode Alpha Names. Length and the string",

0x0416 => "Indexed Color Table Count. Number of colors in table that are actually defined",

0x0417 => "Transparent Index. Index of transparent color, if any.",

0x0419 => "Global Altitude.",

0x041A => "Slices.",

0x041B => "Workflow URL. Length, string.",

0x041C => "Jump To XPEP. Major version, Minor version, Count. Table which can include: Dirty flag, Mod date.",

0x041D => "Alpha Identifiers.",

0x041E => "URL List. Count of URLs, IDs, and strings",

0x0421 => "Version Info. Version, HasRealMergedData, string of writer name, string of reader name, file version.",

0x0BB7 => "Name of clipping path.",

0x2710 => "Print flags information. Version, Center crop marks, Bleed width value, Bleed width scale."

);



/******************************************************************************

* End of Global Variable:     Photoshop_ID_Descriptions

******************************************************************************/













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