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/library/Zend/Pdf/Resource/Image/Png.php

https://bitbucket.org/fabiancarlos/feature_seguimentos
PHP | 380 lines | 247 code | 52 blank | 81 comment | 23 complexity | 7e6055c78748d5dfa990a49d7faed360 MD5 | raw file
  1<?php
  2/**
  3 * Zend Framework
  4 *
  5 * LICENSE
  6 *
  7 * This source file is subject to the new BSD license that is bundled
  8 * with this package in the file LICENSE.txt.
  9 * It is also available through the world-wide-web at this URL:
 10 * http://framework.zend.com/license/new-bsd
 11 * If you did not receive a copy of the license and are unable to
 12 * obtain it through the world-wide-web, please send an email
 13 * to license@zend.com so we can send you a copy immediately.
 14 *
 15 * @category   Zend
 16 * @package    Zend_Pdf
 17 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 18 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 19 * @version    $Id: Png.php 23775 2011-03-01 17:25:24Z ralph $
 20 */
 21
 22
 23/** Internally used classes */
 24require_once 'Zend/Pdf/Element/Array.php';
 25require_once 'Zend/Pdf/Element/Dictionary.php';
 26require_once 'Zend/Pdf/Element/Name.php';
 27require_once 'Zend/Pdf/Element/Numeric.php';
 28require_once 'Zend/Pdf/Element/String/Binary.php';
 29
 30
 31/** Zend_Pdf_Resource_Image */
 32require_once 'Zend/Pdf/Resource/Image.php';
 33
 34/**
 35 * PNG image
 36 *
 37 * @package    Zend_Pdf
 38 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 39 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 40 */
 41class Zend_Pdf_Resource_Image_Png extends Zend_Pdf_Resource_Image
 42{
 43    const PNG_COMPRESSION_DEFAULT_STRATEGY = 0;
 44    const PNG_COMPRESSION_FILTERED = 1;
 45    const PNG_COMPRESSION_HUFFMAN_ONLY = 2;
 46    const PNG_COMPRESSION_RLE = 3;
 47
 48    const PNG_FILTER_NONE = 0;
 49    const PNG_FILTER_SUB = 1;
 50    const PNG_FILTER_UP = 2;
 51    const PNG_FILTER_AVERAGE = 3;
 52    const PNG_FILTER_PAETH = 4;
 53
 54    const PNG_INTERLACING_DISABLED = 0;
 55    const PNG_INTERLACING_ENABLED = 1;
 56
 57    const PNG_CHANNEL_GRAY = 0;
 58    const PNG_CHANNEL_RGB = 2;
 59    const PNG_CHANNEL_INDEXED = 3;
 60    const PNG_CHANNEL_GRAY_ALPHA = 4;
 61    const PNG_CHANNEL_RGB_ALPHA = 6;
 62
 63    protected $_width;
 64    protected $_height;
 65    protected $_imageProperties;
 66
 67    /**
 68     * Object constructor
 69     *
 70     * @param string $imageFileName
 71     * @throws Zend_Pdf_Exception
 72     * @todo Add compression conversions to support compression strategys other than PNG_COMPRESSION_DEFAULT_STRATEGY.
 73     * @todo Add pre-compression filtering.
 74     * @todo Add interlaced image handling.
 75     * @todo Add support for 16-bit images. Requires PDF version bump to 1.5 at least.
 76     * @todo Add processing for all PNG chunks defined in the spec. gAMA etc.
 77     * @todo Fix tRNS chunk support for Indexed Images to a SMask.
 78     */
 79    public function __construct($imageFileName)
 80    {
 81        if (($imageFile = @fopen($imageFileName, 'rb')) === false ) {
 82            require_once 'Zend/Pdf/Exception.php';
 83            throw new Zend_Pdf_Exception( "Can not open '$imageFileName' file for reading." );
 84        }
 85
 86        parent::__construct();
 87
 88        //Check if the file is a PNG
 89        fseek($imageFile, 1, SEEK_CUR); //First signature byte (%)
 90        if ('PNG' != fread($imageFile, 3)) {
 91            require_once 'Zend/Pdf/Exception.php';
 92            throw new Zend_Pdf_Exception('Image is not a PNG');
 93        }
 94        fseek($imageFile, 12, SEEK_CUR); //Signature bytes (Includes the IHDR chunk) IHDR processed linerarly because it doesnt contain a variable chunk length
 95        $wtmp = unpack('Ni',fread($imageFile, 4)); //Unpack a 4-Byte Long
 96        $width = $wtmp['i'];
 97        $htmp = unpack('Ni',fread($imageFile, 4));
 98        $height = $htmp['i'];
 99        $bits = ord(fread($imageFile, 1)); //Higher than 8 bit depths are only supported in later versions of PDF.
100        $color = ord(fread($imageFile, 1));
101
102        $compression = ord(fread($imageFile, 1));
103        $prefilter = ord(fread($imageFile,1));
104
105        if (($interlacing = ord(fread($imageFile,1))) != Zend_Pdf_Resource_Image_Png::PNG_INTERLACING_DISABLED) {
106            require_once 'Zend/Pdf/Exception.php';
107            throw new Zend_Pdf_Exception( "Only non-interlaced images are currently supported." );
108        }
109
110        $this->_width = $width;
111        $this->_height = $height;
112        $this->_imageProperties = array();
113        $this->_imageProperties['bitDepth'] = $bits;
114        $this->_imageProperties['pngColorType'] = $color;
115        $this->_imageProperties['pngFilterType'] = $prefilter;
116        $this->_imageProperties['pngCompressionType'] = $compression;
117        $this->_imageProperties['pngInterlacingType'] = $interlacing;
118
119        fseek($imageFile, 4, SEEK_CUR); //4 Byte Ending Sequence
120        $imageData = '';
121
122        /*
123         * The following loop processes PNG chunks. 4 Byte Longs are packed first give the chunk length
124         * followed by the chunk signature, a four byte code. IDAT and IEND are manditory in any PNG.
125         */
126        while (!feof($imageFile)) {
127            $chunkLengthBytes = fread($imageFile, 4);
128            if ($chunkLengthBytes === false) {
129                require_once 'Zend/Pdf/Exception.php';
130                throw new Zend_Pdf_Exception('Error ocuured while image file reading.');
131            }
132
133            $chunkLengthtmp = unpack('Ni', $chunkLengthBytes);
134            $chunkLength    = $chunkLengthtmp['i'];
135            $chunkType      = fread($imageFile, 4);
136            switch($chunkType) {
137                case 'IDAT': //Image Data
138                    /*
139                     * Reads the actual image data from the PNG file. Since we know at this point that the compression
140                     * strategy is the default strategy, we also know that this data is Zip compressed. We will either copy
141                     * the data directly to the PDF and provide the correct FlateDecode predictor, or decompress the data
142                     * decode the filters and output the data as a raw pixel map.
143                     */
144                    $imageData .= fread($imageFile, $chunkLength);
145                    fseek($imageFile, 4, SEEK_CUR);
146                    break;
147
148                case 'PLTE': //Palette
149                    $paletteData = fread($imageFile, $chunkLength);
150                    fseek($imageFile, 4, SEEK_CUR);
151                    break;
152
153                case 'tRNS': //Basic (non-alpha channel) transparency.
154                    $trnsData = fread($imageFile, $chunkLength);
155                    switch ($color) {
156                        case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY:
157                            $baseColor = ord(substr($trnsData, 1, 1));
158                            $transparencyData = array(new Zend_Pdf_Element_Numeric($baseColor),
159                                                      new Zend_Pdf_Element_Numeric($baseColor));
160                            break;
161
162                        case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB:
163                            $red = ord(substr($trnsData,1,1));
164                            $green = ord(substr($trnsData,3,1));
165                            $blue = ord(substr($trnsData,5,1));
166                            $transparencyData = array(new Zend_Pdf_Element_Numeric($red),
167                                                      new Zend_Pdf_Element_Numeric($red),
168                                                      new Zend_Pdf_Element_Numeric($green),
169                                                      new Zend_Pdf_Element_Numeric($green),
170                                                      new Zend_Pdf_Element_Numeric($blue),
171                                                      new Zend_Pdf_Element_Numeric($blue));
172                            break;
173
174                        case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_INDEXED:
175                            //Find the first transparent color in the index, we will mask that. (This is a bit of a hack. This should be a SMask and mask all entries values).
176                            if(($trnsIdx = strpos($trnsData, "\0")) !== false) {
177                                $transparencyData = array(new Zend_Pdf_Element_Numeric($trnsIdx),
178                                                          new Zend_Pdf_Element_Numeric($trnsIdx));
179                            }
180                            break;
181
182                        case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY_ALPHA:
183                            // Fall through to the next case
184
185                        case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA:
186                            require_once 'Zend/Pdf/Exception.php';
187                            throw new Zend_Pdf_Exception( "tRNS chunk illegal for Alpha Channel Images" );
188                            break;
189                    }
190                    fseek($imageFile, 4, SEEK_CUR); //4 Byte Ending Sequence
191                    break;
192
193                case 'IEND';
194                    break 2; //End the loop too
195
196                default:
197                    fseek($imageFile, $chunkLength + 4, SEEK_CUR); //Skip the section
198                    break;
199            }
200        }
201        fclose($imageFile);
202
203        $compressed = true;
204        $imageDataTmp = '';
205        $smaskData = '';
206        switch ($color) {
207            case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB:
208                $colorSpace = new Zend_Pdf_Element_Name('DeviceRGB');
209                break;
210
211            case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY:
212                $colorSpace = new Zend_Pdf_Element_Name('DeviceGray');
213                break;
214
215            case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_INDEXED:
216                if(empty($paletteData)) {
217                    require_once 'Zend/Pdf/Exception.php';
218                    throw new Zend_Pdf_Exception( "PNG Corruption: No palette data read for indexed type PNG." );
219                }
220                $colorSpace = new Zend_Pdf_Element_Array();
221                $colorSpace->items[] = new Zend_Pdf_Element_Name('Indexed');
222                $colorSpace->items[] = new Zend_Pdf_Element_Name('DeviceRGB');
223                $colorSpace->items[] = new Zend_Pdf_Element_Numeric((strlen($paletteData)/3-1));
224                $paletteObject = $this->_objectFactory->newObject(new Zend_Pdf_Element_String_Binary($paletteData));
225                $colorSpace->items[] = $paletteObject;
226                break;
227
228            case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY_ALPHA:
229                /*
230                 * To decode PNG's with alpha data we must create two images from one. One image will contain the Gray data
231                 * the other will contain the Gray transparency overlay data. The former will become the object data and the latter
232                 * will become the Shadow Mask (SMask).
233                 */
234                if($bits > 8) {
235                    require_once 'Zend/Pdf/Exception.php';
236                    throw new Zend_Pdf_Exception("Alpha PNGs with bit depth > 8 are not yet supported");
237                }
238
239                $colorSpace = new Zend_Pdf_Element_Name('DeviceGray');
240
241                require_once 'Zend/Pdf/ElementFactory.php';
242                $decodingObjFactory = Zend_Pdf_ElementFactory::createFactory(1);
243                $decodingStream = $decodingObjFactory->newStreamObject($imageData);
244                $decodingStream->dictionary->Filter      = new Zend_Pdf_Element_Name('FlateDecode');
245                $decodingStream->dictionary->DecodeParms = new Zend_Pdf_Element_Dictionary();
246                $decodingStream->dictionary->DecodeParms->Predictor        = new Zend_Pdf_Element_Numeric(15);
247                $decodingStream->dictionary->DecodeParms->Columns          = new Zend_Pdf_Element_Numeric($width);
248                $decodingStream->dictionary->DecodeParms->Colors           = new Zend_Pdf_Element_Numeric(2);   //GreyAlpha
249                $decodingStream->dictionary->DecodeParms->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits);
250                $decodingStream->skipFilters();
251
252                $pngDataRawDecoded = $decodingStream->value;
253
254                //Iterate every pixel and copy out gray data and alpha channel (this will be slow)
255                for($pixel = 0, $pixelcount = ($width * $height); $pixel < $pixelcount; $pixel++) {
256                    $imageDataTmp .= $pngDataRawDecoded[($pixel*2)];
257                    $smaskData .= $pngDataRawDecoded[($pixel*2)+1];
258                }
259                $compressed = false;
260                $imageData  = $imageDataTmp; //Overwrite image data with the gray channel without alpha
261                break;
262
263            case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA:
264                /*
265                 * To decode PNG's with alpha data we must create two images from one. One image will contain the RGB data
266                 * the other will contain the Gray transparency overlay data. The former will become the object data and the latter
267                 * will become the Shadow Mask (SMask).
268                 */
269                if($bits > 8) {
270                    require_once 'Zend/Pdf/Exception.php';
271                    throw new Zend_Pdf_Exception("Alpha PNGs with bit depth > 8 are not yet supported");
272                }
273
274                $colorSpace = new Zend_Pdf_Element_Name('DeviceRGB');
275
276                require_once 'Zend/Pdf/ElementFactory.php';
277                $decodingObjFactory = Zend_Pdf_ElementFactory::createFactory(1);
278                $decodingStream = $decodingObjFactory->newStreamObject($imageData);
279                $decodingStream->dictionary->Filter      = new Zend_Pdf_Element_Name('FlateDecode');
280                $decodingStream->dictionary->DecodeParms = new Zend_Pdf_Element_Dictionary();
281                $decodingStream->dictionary->DecodeParms->Predictor        = new Zend_Pdf_Element_Numeric(15);
282                $decodingStream->dictionary->DecodeParms->Columns          = new Zend_Pdf_Element_Numeric($width);
283                $decodingStream->dictionary->DecodeParms->Colors           = new Zend_Pdf_Element_Numeric(4);   //RGBA
284                $decodingStream->dictionary->DecodeParms->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits);
285                $decodingStream->skipFilters();
286
287                $pngDataRawDecoded = $decodingStream->value;
288
289                //Iterate every pixel and copy out rgb data and alpha channel (this will be slow)
290                for($pixel = 0, $pixelcount = ($width * $height); $pixel < $pixelcount; $pixel++) {
291                    $imageDataTmp .= $pngDataRawDecoded[($pixel*4)+0] . $pngDataRawDecoded[($pixel*4)+1] . $pngDataRawDecoded[($pixel*4)+2];
292                    $smaskData .= $pngDataRawDecoded[($pixel*4)+3];
293                }
294
295                $compressed = false;
296                $imageData  = $imageDataTmp; //Overwrite image data with the RGB channel without alpha
297                break;
298
299            default:
300                require_once 'Zend/Pdf/Exception.php';
301                throw new Zend_Pdf_Exception( "PNG Corruption: Invalid color space." );
302        }
303
304        if(empty($imageData)) {
305            require_once 'Zend/Pdf/Exception.php';
306            throw new Zend_Pdf_Exception( "Corrupt PNG Image. Mandatory IDAT chunk not found." );
307        }
308
309        $imageDictionary = $this->_resource->dictionary;
310        if(!empty($smaskData)) {
311            /*
312             * Includes the Alpha transparency data as a Gray Image, then assigns the image as the Shadow Mask for the main image data.
313             */
314            $smaskStream = $this->_objectFactory->newStreamObject($smaskData);
315            $smaskStream->dictionary->Type             = new Zend_Pdf_Element_Name('XObject');
316            $smaskStream->dictionary->Subtype          = new Zend_Pdf_Element_Name('Image');
317            $smaskStream->dictionary->Width            = new Zend_Pdf_Element_Numeric($width);
318            $smaskStream->dictionary->Height           = new Zend_Pdf_Element_Numeric($height);
319            $smaskStream->dictionary->ColorSpace       = new Zend_Pdf_Element_Name('DeviceGray');
320            $smaskStream->dictionary->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits);
321            $imageDictionary->SMask = $smaskStream;
322
323            // Encode stream with FlateDecode filter
324            $smaskStreamDecodeParms = array();
325            $smaskStreamDecodeParms['Predictor']        = new Zend_Pdf_Element_Numeric(15);
326            $smaskStreamDecodeParms['Columns']          = new Zend_Pdf_Element_Numeric($width);
327            $smaskStreamDecodeParms['Colors']           = new Zend_Pdf_Element_Numeric(1);
328            $smaskStreamDecodeParms['BitsPerComponent'] = new Zend_Pdf_Element_Numeric(8);
329            $smaskStream->dictionary->DecodeParms  = new Zend_Pdf_Element_Dictionary($smaskStreamDecodeParms);
330            $smaskStream->dictionary->Filter       = new Zend_Pdf_Element_Name('FlateDecode');
331        }
332
333        if(!empty($transparencyData)) {
334            //This is experimental and not properly tested.
335            $imageDictionary->Mask = new Zend_Pdf_Element_Array($transparencyData);
336        }
337
338        $imageDictionary->Width            = new Zend_Pdf_Element_Numeric($width);
339        $imageDictionary->Height           = new Zend_Pdf_Element_Numeric($height);
340        $imageDictionary->ColorSpace       = $colorSpace;
341        $imageDictionary->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits);
342        $imageDictionary->Filter       = new Zend_Pdf_Element_Name('FlateDecode');
343
344        $decodeParms = array();
345        $decodeParms['Predictor']        = new Zend_Pdf_Element_Numeric(15); // Optimal prediction
346        $decodeParms['Columns']          = new Zend_Pdf_Element_Numeric($width);
347        $decodeParms['Colors']           = new Zend_Pdf_Element_Numeric((($color==Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB || $color==Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA)?(3):(1)));
348        $decodeParms['BitsPerComponent'] = new Zend_Pdf_Element_Numeric($bits);
349        $imageDictionary->DecodeParms  = new Zend_Pdf_Element_Dictionary($decodeParms);
350
351        //Include only the image IDAT section data.
352        $this->_resource->value = $imageData;
353
354        //Skip double compression
355        if ($compressed) {
356            $this->_resource->skipFilters();
357        }
358    }
359
360    /**
361     * Image width
362     */
363    public function getPixelWidth() {
364    return $this->_width;
365    }
366
367    /**
368     * Image height
369     */
370    public function getPixelHeight() {
371        return $this->_height;
372    }
373
374    /**
375     * Image properties
376     */
377    public function getProperties() {
378        return $this->_imageProperties;
379    }
380}