8398c9048d
code was modified slightly, so the code differs from the original downloadable 1.9.5 version
326 lines
11 KiB
PHP
326 lines
11 KiB
PHP
<?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
|
|
* @subpackage FileParser
|
|
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
|
|
* @license http://framework.zend.com/license/new-bsd New BSD License
|
|
* @version $Id: Png.php 16971 2009-07-22 18:05:45Z mikaelkael $
|
|
*/
|
|
|
|
/** Zend_Pdf_FileParser_Image */
|
|
require_once 'Zend/Pdf/FileParser/Image.php';
|
|
|
|
|
|
/**
|
|
* Abstract base class for Image file parsers.
|
|
*
|
|
* @package Zend_Pdf
|
|
* @subpackage FileParser
|
|
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
|
|
* @license http://framework.zend.com/license/new-bsd New BSD License
|
|
*/
|
|
class Zend_Pdf_FileParser_Image_Png extends Zend_Pdf_FileParser_Image
|
|
{
|
|
protected $_isPNG;
|
|
protected $_width;
|
|
protected $_height;
|
|
protected $_bits;
|
|
protected $_color;
|
|
protected $_compression;
|
|
protected $_preFilter;
|
|
protected $_interlacing;
|
|
|
|
protected $_imageData;
|
|
protected $_paletteData;
|
|
protected $_transparencyData;
|
|
|
|
/**** Public Interface ****/
|
|
|
|
public function getWidth() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_width;
|
|
}
|
|
|
|
public function getHeight() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_width;
|
|
}
|
|
|
|
public function getBitDepth() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_bits;
|
|
}
|
|
|
|
public function getColorSpace() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_color;
|
|
}
|
|
|
|
public function getCompressionStrategy() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_compression;
|
|
}
|
|
|
|
public function getPaethFilter() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_preFilter;
|
|
}
|
|
|
|
public function getInterlacingMode() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_interlacing;
|
|
}
|
|
|
|
public function getRawImageData() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_imageData;
|
|
}
|
|
|
|
public function getRawPaletteData() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_paletteData;
|
|
}
|
|
|
|
public function getRawTransparencyData() {
|
|
if(!$this->_isParsed) {
|
|
$this->parse();
|
|
}
|
|
return $this->_transparencyData;
|
|
}
|
|
|
|
/* Semi-Concrete Class Implementation */
|
|
|
|
/**
|
|
* Verifies that the image file is in the expected format.
|
|
*
|
|
* @throws Zend_Pdf_Exception
|
|
*/
|
|
public function screen()
|
|
{
|
|
if ($this->_isScreened) {
|
|
return;
|
|
}
|
|
return $this->_checkSignature();
|
|
}
|
|
|
|
/**
|
|
* Reads and parses the image data from the file on disk.
|
|
*
|
|
* @throws Zend_Pdf_Exception
|
|
*/
|
|
public function parse()
|
|
{
|
|
if ($this->_isParsed) {
|
|
return;
|
|
}
|
|
|
|
/* Screen the font file first, if it hasn't been done yet.
|
|
*/
|
|
$this->screen();
|
|
|
|
$this->_parseIHDRChunk();
|
|
$this->_parseChunks();
|
|
}
|
|
|
|
|
|
protected function _parseSignature() {
|
|
$this->moveToOffset(1); //Skip the first byte (%)
|
|
if('PNG' != $this->readBytes(3)) {
|
|
$this->_isPNG = false;
|
|
} else {
|
|
$this->_isPNG = true;
|
|
}
|
|
}
|
|
|
|
protected function _checkSignature() {
|
|
if(!isset($this->_isPNG)) {
|
|
$this->_parseSignature();
|
|
}
|
|
return $this->_isPNG;
|
|
}
|
|
|
|
protected function _parseChunks() {
|
|
$this->moveToOffset(33); //Variable chunks start at the end of IHDR
|
|
|
|
//Start processing chunks. If there are no more bytes to read parsing is complete.
|
|
$size = $this->getSize();
|
|
while($size - $this->getOffset() >= 8) {
|
|
$chunkLength = $this->readUInt(4);
|
|
if($chunkLength < 0 || ($chunkLength + $this->getOffset() + 4) > $size) {
|
|
throw new Zend_Pdf_Exception("PNG Corrupt: Invalid Chunk Size In File.");
|
|
}
|
|
|
|
$chunkType = $this->readBytes(4);
|
|
$offset = $this->getOffset();
|
|
|
|
//If we know how to process the chunk, do it here, else ignore the chunk and move on to the next
|
|
switch($chunkType) {
|
|
case 'IDAT': // This chunk may appear more than once. It contains the actual image data.
|
|
$this->_parseIDATChunk($offset, $chunkLength);
|
|
break;
|
|
|
|
case 'PLTE': // This chunk contains the image palette.
|
|
$this->_parsePLTEChunk($offset, $chunkLength);
|
|
break;
|
|
|
|
case 'tRNS': // This chunk contains non-alpha channel transparency data
|
|
$this->_parseTRNSChunk($offset, $chunkLength);
|
|
break;
|
|
|
|
case 'IEND':
|
|
break 2; //End the loop too
|
|
|
|
//@TODO Implement the rest of the PNG chunks. (There are many not implemented here)
|
|
}
|
|
if($offset + $chunkLength + 4 < $size) {
|
|
$this->moveToOffset($offset + $chunkLength + 4); //Skip past the data finalizer. (Don't rely on the parse to leave the offsets correct)
|
|
}
|
|
}
|
|
if(empty($this->_imageData)) {
|
|
throw new Zend_Pdf_Exception ( "This PNG is corrupt. All png must contain IDAT chunks." );
|
|
}
|
|
}
|
|
|
|
protected function _parseIHDRChunk() {
|
|
$this->moveToOffset(12); //IHDR must always start at offset 12 and run for 17 bytes
|
|
if(!$this->readBytes(4) == 'IHDR') {
|
|
throw new Zend_Pdf_Exception( "This PNG is corrupt. The first chunk in a PNG file must be IHDR." );
|
|
}
|
|
$this->_width = $this->readUInt(4);
|
|
$this->_height = $this->readUInt(4);
|
|
$this->_bits = $this->readInt(1);
|
|
$this->_color = $this->readInt(1);
|
|
$this->_compression = $this->readInt(1);
|
|
$this->_preFilter = $this->readInt(1);
|
|
$this->_interlacing = $this->readInt(1);
|
|
if($this->_interlacing != Zend_Pdf_Image::PNG_INTERLACING_DISABLED) {
|
|
throw new Zend_Pdf_Exception( "Only non-interlaced images are currently supported." );
|
|
}
|
|
}
|
|
|
|
protected function _parseIDATChunk($chunkOffset, $chunkLength) {
|
|
$this->moveToOffset($chunkOffset);
|
|
if(!isset($this->_imageData)) {
|
|
$this->_imageData = $this->readBytes($chunkLength);
|
|
} else {
|
|
$this->_imageData .= $this->readBytes($chunkLength);
|
|
}
|
|
}
|
|
|
|
protected function _parsePLTEChunk($chunkOffset, $chunkLength) {
|
|
$this->moveToOffset($chunkOffset);
|
|
$this->_paletteData = $this->readBytes($chunkLength);
|
|
}
|
|
|
|
protected function _parseTRNSChunk($chunkOffset, $chunkLength) {
|
|
$this->moveToOffset($chunkOffset);
|
|
|
|
//Processing of tRNS data varies dependending on the color depth
|
|
|
|
switch($this->_color) {
|
|
case Zend_Pdf_Image::PNG_CHANNEL_GRAY:
|
|
$baseColor = $this->readInt(1);
|
|
$this->_transparencyData = array($baseColor, $baseColor);
|
|
break;
|
|
|
|
case Zend_Pdf_Image::PNG_CHANNEL_RGB:
|
|
|
|
//@TODO Fix this hack.
|
|
//This parser cheats and only uses the lsb's (and only works with < 16 bit depth images)
|
|
|
|
/*
|
|
From the standard:
|
|
|
|
For color type 2 (truecolor), the tRNS chunk contains a single RGB color value, stored in the format:
|
|
|
|
Red: 2 bytes, range 0 .. (2^bitdepth)-1
|
|
Green: 2 bytes, range 0 .. (2^bitdepth)-1
|
|
Blue: 2 bytes, range 0 .. (2^bitdepth)-1
|
|
|
|
(If the image bit depth is less than 16, the least significant bits are used and the others are 0.)
|
|
Pixels of the specified color value are to be treated as transparent (equivalent to alpha value 0);
|
|
all other pixels are to be treated as fully opaque (alpha value 2bitdepth-1).
|
|
|
|
*/
|
|
|
|
$red = $this->readInt(1);
|
|
$this->skipBytes(1);
|
|
$green = $this->readInt(1);
|
|
$this->skipBytes(1);
|
|
$blue = $this->readInt(1);
|
|
|
|
$this->_transparencyData = array($red, $red, $green, $green, $blue, $blue);
|
|
|
|
break;
|
|
|
|
case Zend_Pdf_Image::PNG_CHANNEL_INDEXED:
|
|
|
|
//@TODO Fix this hack.
|
|
//This parser cheats too. It only masks the first color in the palette.
|
|
|
|
/*
|
|
From the standard:
|
|
|
|
For color type 3 (indexed color), the tRNS chunk contains a series of one-byte alpha values, corresponding to entries in the PLTE chunk:
|
|
|
|
Alpha for palette index 0: 1 byte
|
|
Alpha for palette index 1: 1 byte
|
|
...etc...
|
|
|
|
Each entry indicates that pixels of the corresponding palette index must be treated as having the specified alpha value.
|
|
Alpha values have the same interpretation as in an 8-bit full alpha channel: 0 is fully transparent, 255 is fully opaque,
|
|
regardless of image bit depth. The tRNS chunk must not contain more alpha values than there are palette entries,
|
|
but tRNS can contain fewer values than there are palette entries. In this case, the alpha value for all remaining palette
|
|
entries is assumed to be 255. In the common case in which only palette index 0 need be made transparent, only a one-byte
|
|
tRNS chunk is needed.
|
|
|
|
*/
|
|
|
|
$tmpData = $this->readBytes($chunkLength);
|
|
if(($trnsIdx = strpos($tmpData, chr(0))) !== false) {
|
|
$this->_transparencyData = array($trnsIdx, $trnsIdx);
|
|
}
|
|
|
|
break;
|
|
|
|
case Zend_Pdf_Image::PNG_CHANNEL_GRAY_ALPHA:
|
|
//Fall through to the next case
|
|
case Zend_Pdf_Image::PING_CHANNEL_RGB_ALPHA:
|
|
throw new Zend_Pdf_Exception( "tRNS chunk illegal for Alpha Channel Images" );
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
|