<?php /** * Zend Framework * * LICENSE * * This source file is subject to the new BSD license that is bundled * with this package in the file LICENSE.txt. * It is also available through the world-wide-web at this URL: * http://framework.zend.com/license/new-bsd * If you did not receive a copy of the license and are unable to * obtain it through the world-wide-web, please send an email * to license@zend.com so we can send you a copy immediately. * * @category Zend * @package Zend_Pdf * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com) * @license http://framework.zend.com/license/new-bsd New BSD License * @version $Id: Png.php 24593 2012-01-05 20:35:02Z matthew $ */ /** Internally used classes */ require_once 'Zend/Pdf/Element/Array.php'; require_once 'Zend/Pdf/Element/Dictionary.php'; require_once 'Zend/Pdf/Element/Name.php'; require_once 'Zend/Pdf/Element/Numeric.php'; require_once 'Zend/Pdf/Element/String/Binary.php'; /** Zend_Pdf_Resource_Image */ require_once 'Zend/Pdf/Resource/Image.php'; /** * PNG image * * @package Zend_Pdf * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com) * @license http://framework.zend.com/license/new-bsd New BSD License */ class Zend_Pdf_Resource_Image_Png extends Zend_Pdf_Resource_Image { const PNG_COMPRESSION_DEFAULT_STRATEGY = 0; const PNG_COMPRESSION_FILTERED = 1; const PNG_COMPRESSION_HUFFMAN_ONLY = 2; const PNG_COMPRESSION_RLE = 3; const PNG_FILTER_NONE = 0; const PNG_FILTER_SUB = 1; const PNG_FILTER_UP = 2; const PNG_FILTER_AVERAGE = 3; const PNG_FILTER_PAETH = 4; const PNG_INTERLACING_DISABLED = 0; const PNG_INTERLACING_ENABLED = 1; const PNG_CHANNEL_GRAY = 0; const PNG_CHANNEL_RGB = 2; const PNG_CHANNEL_INDEXED = 3; const PNG_CHANNEL_GRAY_ALPHA = 4; const PNG_CHANNEL_RGB_ALPHA = 6; protected $_width; protected $_height; protected $_imageProperties; /** * Object constructor * * @param string $imageFileName * @throws Zend_Pdf_Exception * @todo Add compression conversions to support compression strategys other than PNG_COMPRESSION_DEFAULT_STRATEGY. * @todo Add pre-compression filtering. * @todo Add interlaced image handling. * @todo Add support for 16-bit images. Requires PDF version bump to 1.5 at least. * @todo Add processing for all PNG chunks defined in the spec. gAMA etc. * @todo Fix tRNS chunk support for Indexed Images to a SMask. */ public function __construct($imageFileName) { if (($imageFile = @fopen($imageFileName, 'rb')) === false ) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "Can not open '$imageFileName' file for reading." ); } parent::__construct(); //Check if the file is a PNG fseek($imageFile, 1, SEEK_CUR); //First signature byte (%) if ('PNG' != fread($imageFile, 3)) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception('Image is not a PNG'); } fseek($imageFile, 12, SEEK_CUR); //Signature bytes (Includes the IHDR chunk) IHDR processed linerarly because it doesnt contain a variable chunk length $wtmp = unpack('Ni',fread($imageFile, 4)); //Unpack a 4-Byte Long $width = $wtmp['i']; $htmp = unpack('Ni',fread($imageFile, 4)); $height = $htmp['i']; $bits = ord(fread($imageFile, 1)); //Higher than 8 bit depths are only supported in later versions of PDF. $color = ord(fread($imageFile, 1)); $compression = ord(fread($imageFile, 1)); $prefilter = ord(fread($imageFile,1)); if (($interlacing = ord(fread($imageFile,1))) != Zend_Pdf_Resource_Image_Png::PNG_INTERLACING_DISABLED) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "Only non-interlaced images are currently supported." ); } $this->_width = $width; $this->_height = $height; $this->_imageProperties = array(); $this->_imageProperties['bitDepth'] = $bits; $this->_imageProperties['pngColorType'] = $color; $this->_imageProperties['pngFilterType'] = $prefilter; $this->_imageProperties['pngCompressionType'] = $compression; $this->_imageProperties['pngInterlacingType'] = $interlacing; fseek($imageFile, 4, SEEK_CUR); //4 Byte Ending Sequence $imageData = ''; /* * The following loop processes PNG chunks. 4 Byte Longs are packed first give the chunk length * followed by the chunk signature, a four byte code. IDAT and IEND are manditory in any PNG. */ while (!feof($imageFile)) { $chunkLengthBytes = fread($imageFile, 4); if ($chunkLengthBytes === false) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception('Error ocuured while image file reading.'); } $chunkLengthtmp = unpack('Ni', $chunkLengthBytes); $chunkLength = $chunkLengthtmp['i']; $chunkType = fread($imageFile, 4); switch($chunkType) { case 'IDAT': //Image Data /* * Reads the actual image data from the PNG file. Since we know at this point that the compression * strategy is the default strategy, we also know that this data is Zip compressed. We will either copy * the data directly to the PDF and provide the correct FlateDecode predictor, or decompress the data * decode the filters and output the data as a raw pixel map. */ $imageData .= fread($imageFile, $chunkLength); fseek($imageFile, 4, SEEK_CUR); break; case 'PLTE': //Palette $paletteData = fread($imageFile, $chunkLength); fseek($imageFile, 4, SEEK_CUR); break; case 'tRNS': //Basic (non-alpha channel) transparency. $trnsData = fread($imageFile, $chunkLength); switch ($color) { case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY: $baseColor = ord(substr($trnsData, 1, 1)); $transparencyData = array(new Zend_Pdf_Element_Numeric($baseColor), new Zend_Pdf_Element_Numeric($baseColor)); break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB: $red = ord(substr($trnsData,1,1)); $green = ord(substr($trnsData,3,1)); $blue = ord(substr($trnsData,5,1)); $transparencyData = array(new Zend_Pdf_Element_Numeric($red), new Zend_Pdf_Element_Numeric($red), new Zend_Pdf_Element_Numeric($green), new Zend_Pdf_Element_Numeric($green), new Zend_Pdf_Element_Numeric($blue), new Zend_Pdf_Element_Numeric($blue)); break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_INDEXED: //Find the first transparent color in the index, we will mask that. (This is a bit of a hack. This should be a SMask and mask all entries values). if(($trnsIdx = strpos($trnsData, "\0")) !== false) { $transparencyData = array(new Zend_Pdf_Element_Numeric($trnsIdx), new Zend_Pdf_Element_Numeric($trnsIdx)); } break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY_ALPHA: // Fall through to the next case case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA: require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "tRNS chunk illegal for Alpha Channel Images" ); break; } fseek($imageFile, 4, SEEK_CUR); //4 Byte Ending Sequence break; case 'IEND'; break 2; //End the loop too default: fseek($imageFile, $chunkLength + 4, SEEK_CUR); //Skip the section break; } } fclose($imageFile); $compressed = true; $imageDataTmp = ''; $smaskData = ''; switch ($color) { case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB: $colorSpace = new Zend_Pdf_Element_Name('DeviceRGB'); break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY: $colorSpace = new Zend_Pdf_Element_Name('DeviceGray'); break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_INDEXED: if(empty($paletteData)) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "PNG Corruption: No palette data read for indexed type PNG." ); } $colorSpace = new Zend_Pdf_Element_Array(); $colorSpace->items[] = new Zend_Pdf_Element_Name('Indexed'); $colorSpace->items[] = new Zend_Pdf_Element_Name('DeviceRGB'); $colorSpace->items[] = new Zend_Pdf_Element_Numeric((strlen($paletteData)/3-1)); $paletteObject = $this->_objectFactory->newObject(new Zend_Pdf_Element_String_Binary($paletteData)); $colorSpace->items[] = $paletteObject; break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_GRAY_ALPHA: /* * To decode PNG's with alpha data we must create two images from one. One image will contain the Gray data * the other will contain the Gray transparency overlay data. The former will become the object data and the latter * will become the Shadow Mask (SMask). */ if($bits > 8) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception("Alpha PNGs with bit depth > 8 are not yet supported"); } $colorSpace = new Zend_Pdf_Element_Name('DeviceGray'); require_once 'Zend/Pdf/ElementFactory.php'; $decodingObjFactory = Zend_Pdf_ElementFactory::createFactory(1); $decodingStream = $decodingObjFactory->newStreamObject($imageData); $decodingStream->dictionary->Filter = new Zend_Pdf_Element_Name('FlateDecode'); $decodingStream->dictionary->DecodeParms = new Zend_Pdf_Element_Dictionary(); $decodingStream->dictionary->DecodeParms->Predictor = new Zend_Pdf_Element_Numeric(15); $decodingStream->dictionary->DecodeParms->Columns = new Zend_Pdf_Element_Numeric($width); $decodingStream->dictionary->DecodeParms->Colors = new Zend_Pdf_Element_Numeric(2); //GreyAlpha $decodingStream->dictionary->DecodeParms->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits); $decodingStream->skipFilters(); $pngDataRawDecoded = $decodingStream->value; //Iterate every pixel and copy out gray data and alpha channel (this will be slow) for($pixel = 0, $pixelcount = ($width * $height); $pixel < $pixelcount; $pixel++) { $imageDataTmp .= $pngDataRawDecoded[($pixel*2)]; $smaskData .= $pngDataRawDecoded[($pixel*2)+1]; } $compressed = false; $imageData = $imageDataTmp; //Overwrite image data with the gray channel without alpha break; case Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA: /* * To decode PNG's with alpha data we must create two images from one. One image will contain the RGB data * the other will contain the Gray transparency overlay data. The former will become the object data and the latter * will become the Shadow Mask (SMask). */ if($bits > 8) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception("Alpha PNGs with bit depth > 8 are not yet supported"); } $colorSpace = new Zend_Pdf_Element_Name('DeviceRGB'); require_once 'Zend/Pdf/ElementFactory.php'; $decodingObjFactory = Zend_Pdf_ElementFactory::createFactory(1); $decodingStream = $decodingObjFactory->newStreamObject($imageData); $decodingStream->dictionary->Filter = new Zend_Pdf_Element_Name('FlateDecode'); $decodingStream->dictionary->DecodeParms = new Zend_Pdf_Element_Dictionary(); $decodingStream->dictionary->DecodeParms->Predictor = new Zend_Pdf_Element_Numeric(15); $decodingStream->dictionary->DecodeParms->Columns = new Zend_Pdf_Element_Numeric($width); $decodingStream->dictionary->DecodeParms->Colors = new Zend_Pdf_Element_Numeric(4); //RGBA $decodingStream->dictionary->DecodeParms->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits); $decodingStream->skipFilters(); $pngDataRawDecoded = $decodingStream->value; //Iterate every pixel and copy out rgb data and alpha channel (this will be slow) for($pixel = 0, $pixelcount = ($width * $height); $pixel < $pixelcount; $pixel++) { $imageDataTmp .= $pngDataRawDecoded[($pixel*4)+0] . $pngDataRawDecoded[($pixel*4)+1] . $pngDataRawDecoded[($pixel*4)+2]; $smaskData .= $pngDataRawDecoded[($pixel*4)+3]; } $compressed = false; $imageData = $imageDataTmp; //Overwrite image data with the RGB channel without alpha break; default: require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "PNG Corruption: Invalid color space." ); } if(empty($imageData)) { require_once 'Zend/Pdf/Exception.php'; throw new Zend_Pdf_Exception( "Corrupt PNG Image. Mandatory IDAT chunk not found." ); } $imageDictionary = $this->_resource->dictionary; if(!empty($smaskData)) { /* * Includes the Alpha transparency data as a Gray Image, then assigns the image as the Shadow Mask for the main image data. */ $smaskStream = $this->_objectFactory->newStreamObject($smaskData); $smaskStream->dictionary->Type = new Zend_Pdf_Element_Name('XObject'); $smaskStream->dictionary->Subtype = new Zend_Pdf_Element_Name('Image'); $smaskStream->dictionary->Width = new Zend_Pdf_Element_Numeric($width); $smaskStream->dictionary->Height = new Zend_Pdf_Element_Numeric($height); $smaskStream->dictionary->ColorSpace = new Zend_Pdf_Element_Name('DeviceGray'); $smaskStream->dictionary->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits); $imageDictionary->SMask = $smaskStream; // Encode stream with FlateDecode filter $smaskStreamDecodeParms = array(); $smaskStreamDecodeParms['Predictor'] = new Zend_Pdf_Element_Numeric(15); $smaskStreamDecodeParms['Columns'] = new Zend_Pdf_Element_Numeric($width); $smaskStreamDecodeParms['Colors'] = new Zend_Pdf_Element_Numeric(1); $smaskStreamDecodeParms['BitsPerComponent'] = new Zend_Pdf_Element_Numeric(8); $smaskStream->dictionary->DecodeParms = new Zend_Pdf_Element_Dictionary($smaskStreamDecodeParms); $smaskStream->dictionary->Filter = new Zend_Pdf_Element_Name('FlateDecode'); } if(!empty($transparencyData)) { //This is experimental and not properly tested. $imageDictionary->Mask = new Zend_Pdf_Element_Array($transparencyData); } $imageDictionary->Width = new Zend_Pdf_Element_Numeric($width); $imageDictionary->Height = new Zend_Pdf_Element_Numeric($height); $imageDictionary->ColorSpace = $colorSpace; $imageDictionary->BitsPerComponent = new Zend_Pdf_Element_Numeric($bits); $imageDictionary->Filter = new Zend_Pdf_Element_Name('FlateDecode'); $decodeParms = array(); $decodeParms['Predictor'] = new Zend_Pdf_Element_Numeric(15); // Optimal prediction $decodeParms['Columns'] = new Zend_Pdf_Element_Numeric($width); $decodeParms['Colors'] = new Zend_Pdf_Element_Numeric((($color==Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB || $color==Zend_Pdf_Resource_Image_Png::PNG_CHANNEL_RGB_ALPHA)?(3):(1))); $decodeParms['BitsPerComponent'] = new Zend_Pdf_Element_Numeric($bits); $imageDictionary->DecodeParms = new Zend_Pdf_Element_Dictionary($decodeParms); //Include only the image IDAT section data. $this->_resource->value = $imageData; //Skip double compression if ($compressed) { $this->_resource->skipFilters(); } } /** * Image width */ public function getPixelWidth() { return $this->_width; } /** * Image height */ public function getPixelHeight() { return $this->_height; } /** * Image properties */ public function getProperties() { return $this->_imageProperties; } }