/php/lib/Gloo/Image/Helper.php

<?php

/**
 *
 * @author rajeevj
 */
class Gloo_Image_Helper {

    function __construct() {

    }

    /**
     *
     * @param <type> $imageURI - The URI on internet where this image is available
     * @return <type>  - image binary data fetched from this URI
     *
     */
    static function getDataFromURI($imageURI) {
        //use curl to pull image data
        $ch = curl_init($imageURI);
        curl_setopt($ch, CURLOPT_HEADER, 0);
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
        curl_setopt($ch, CURLOPT_BINARYTRANSFER, 1);
        $imageData = curl_exec($ch);
        curl_close($ch);

        return $imageData;
    }

    /**
     *
     * @param <type> $imageData - image binary data, stored as a string
     * @return <type> - Dimensions of this image binary
     *
     */
    static function getDimensions($imageData) {


        //created an image from raw data using GD2 library
        $oSourceImage = imagecreatefromstring($imageData);
        if ($oSourceImage == false) {
            //unrecoverable error
            $errorMsg = "GD2 : Not able to create source image from supplied file data ";
            trigger_error($errorMsg, E_USER_ERROR);
        }


        //original image dimensions
        $nWidth = imagesx($oSourceImage);
        $nHeight = imagesy($oSourceImage);
        $dimensions = array('height' => $nHeight, 'width' => $nWidth);
        return $dimensions;
    }

    /**
     *
     * @param <type> $width original image width
     * @param <type> $height original image height
     * @param <type> $frameWidth scale original image width to this width
     * @return <type> new dimensions
     *
     *
     */
    static function getScaledDimensions($width, $height, $frameWidth, $frameHeight=NULL) {

        if (empty($frameHeight)) {
            //Determine frame height from original aspect ratio
            $frameHeight = ($height / $width) * ($frameWidth);
        }

        //first try original dimensions for frame
        $newHeight = $height;
        $newWidth = $width;

        //calculate new height/ width using aspect-ratio
        if ($newHeight > $frameHeight) {
            $aspectRatio = ($frameHeight / $newHeight);
            $newHeight = $aspectRatio * $newHeight;
            $newWidth = $aspectRatio * $newWidth;
        }

        if ($newWidth > $frameWidth) {
            $aspectRatio = ($frameWidth / $newWidth);
            $newHeight = $aspectRatio * $newHeight;
            $newWidth = $aspectRatio * $newWidth;
        }

        //Round up to nearest integer
        $newWidth = floor($newWidth);
        $newHeight = floor($newHeight);
        $dimensions = array('width' => $newWidth, 'height' => $newHeight);
        return $dimensions;
    }

    /**
     *
     *  Take an image binary and resize it to fit frame width and height
     *
     * @param <type> $sImageData source Image file binary data
     * @param <type> $frameWidth  frame width to resize
     * @param <type> $frameHeight frame height to resize
     * @return <type> - New resized image binary
     *
     */
    static function getResizedImage($sImageData, $frameWidth, $frameHeight) {

        $oSourceImage = imagecreatefromstring($sImageData);
        if ($oSourceImage == false) {
            //unrecoverable error
            $errorMsg = "GD2 : Not able to create source image from supplied file data ";
            trigger_error($errorMsg, E_USER_ERROR);
        }
        //original width and height
        $nWidth = imagesx($oSourceImage);
        $nHeight = imagesy($oSourceImage);
        //we try original dimensions for frame
        $nDestinationHeight = $nHeight;
        $nDestinationWidth = $nWidth;
        //calculate new height/ width using aspect-ratio
        if ($nDestinationHeight > $frameHeight) {
            $aspectRatio = ($frameHeight / $nDestinationHeight);
            $nDestinationHeight = $aspectRatio * $nDestinationHeight;
            $nDestinationWidth = $aspectRatio * $nDestinationWidth;
        }

        if ($nDestinationWidth > $frameWidth) {
            $aspectRatio = ($frameWidth / $nDestinationWidth);
            $nDestinationHeight = $aspectRatio * $nDestinationHeight;
            $nDestinationWidth = $aspectRatio * $nDestinationWidth;
        }
        //Round up to nearest integer
        $nDestinationWidth = floor($nDestinationWidth);
        $nDestinationHeight = floor($nDestinationHeight);

        //an image identifier representing a blank image of specified size
        $oDestinationImage = imagecreatetruecolor($nDestinationWidth, $nDestinationHeight);
        //http://in2.php.net/manual/en/function.imagecopyresized.php
        // resize the image
        imagecopyresized($oDestinationImage,
                $oSourceImage, 0, 0, 0, 0,
                $nDestinationWidth, $nDestinationHeight,
                $nWidth, $nHeight);

        ob_start();
        //default is 75. is Quality 75 good enough for us?
        imageJPEG($oDestinationImage, NULL, 75);
        $sNewImage = ob_get_contents();
        ob_end_clean();
        // Free up memory
        imagedestroy($oDestinationImage);
        return $sNewImage;
    }

}

?>