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<?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) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
* @version $Id: Compression.php 18993 2009-11-15 17:09:16Z alexander $
*/
/** Zend_Pdf_Filter_Interface */
require_once 'Zend/Pdf/Filter/Interface.php';
/**
* ASCII85 stream filter
*
* @package Zend_Pdf
* @copyright Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
* @license http://framework.zend.com/license/new-bsd New BSD License
*/
abstract class Zend_Pdf_Filter_Compression implements Zend_Pdf_Filter_Interface
{
/**
* Paeth prediction function
*
* @param integer $a
* @param integer $b
* @param integer $c
* @return integer
*/
private static function _paeth($a, $b, $c)
{
// $a - left, $b - above, $c - upper left
$p = $a + $b - $c; // initial estimate
$pa = abs($p - $a); // distances to a, b, c
$pb = abs($p - $b);
$pc = abs($p - $c);
// return nearest of a,b,c,
// breaking ties in order a,b,c.
if ($pa <= $pb && $pa <= $pc) {
return $a;
} else if ($pb <= $pc) {
return $b;
} else {
return $c;
}
}
/**
* Get Predictor decode param value
*
* @param array $params
* @return integer
* @throws Zend_Pdf_Exception
*/
private static function _getPredictorValue(&$params)
{
if (isset($params['Predictor'])) {
$predictor = $params['Predictor'];
if ($predictor != 1 && $predictor != 2 &&
$predictor != 10 && $predictor != 11 && $predictor != 12 &&
$predictor != 13 && $predictor != 14 && $predictor != 15) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Invalid value of \'Predictor\' decode param - ' . $predictor . '.' );
}
return $predictor;
} else {
return 1;
}
}
/**
* Get Colors decode param value
*
* @param array $params
* @return integer
* @throws Zend_Pdf_Exception
*/
private static function _getColorsValue(&$params)
{
if (isset($params['Colors'])) {
$colors = $params['Colors'];
if ($colors != 1 && $colors != 2 && $colors != 3 && $colors != 4) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Invalid value of \'Color\' decode param - ' . $colors . '.' );
}
return $colors;
} else {
return 1;
}
}
/**
* Get BitsPerComponent decode param value
*
* @param array $params
* @return integer
* @throws Zend_Pdf_Exception
*/
private static function _getBitsPerComponentValue(&$params)
{
if (isset($params['BitsPerComponent'])) {
$bitsPerComponent = $params['BitsPerComponent'];
if ($bitsPerComponent != 1 && $bitsPerComponent != 2 &&
$bitsPerComponent != 4 && $bitsPerComponent != 8 &&
$bitsPerComponent != 16 ) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Invalid value of \'BitsPerComponent\' decode param - ' . $bitsPerComponent . '.' );
}
return $bitsPerComponent;
} else {
return 8;
}
}
/**
* Get Columns decode param value
*
* @param array $params
* @return integer
*/
private static function _getColumnsValue(&$params)
{
if (isset($params['Columns'])) {
return $params['Columns'];
} else {
return 1;
}
}
/**
* Convert stream data according to the filter params set before encoding.
*
* @param string $data
* @param array $params
* @return string
* @throws Zend_Pdf_Exception
*/
protected static function _applyEncodeParams($data, $params) {
$predictor = self::_getPredictorValue($params);
$colors = self::_getColorsValue($params);
$bitsPerComponent = self::_getBitsPerComponentValue($params);
$columns = self::_getColumnsValue($params);
/** None of prediction */
if ($predictor == 1) {
return $data;
}
/** TIFF Predictor 2 */
if ($predictor == 2) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Not implemented yet' );
}
/** Optimal PNG prediction */
if ($predictor == 15) {
/** Use Paeth prediction as optimal */
$predictor = 14;
}
/** PNG prediction */
if ($predictor == 10 || /** None of prediction */
$predictor == 11 || /** Sub prediction */
$predictor == 12 || /** Up prediction */
$predictor == 13 || /** Average prediction */
$predictor == 14 /** Paeth prediction */
) {
$predictor -= 10;
if($bitsPerComponent == 16) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception("PNG Prediction with bit depth greater than 8 not yet supported.");
}
$bitsPerSample = $bitsPerComponent*$colors;
$bytesPerSample = (int)(($bitsPerSample + 7)/8); // (int)ceil(...) emulation
$bytesPerRow = (int)(($bitsPerSample*$columns + 7)/8); // (int)ceil(...) emulation
$rows = strlen($data)/$bytesPerRow;
$output = '';
$offset = 0;
if (!is_integer($rows)) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Wrong data length.');
}
switch ($predictor) {
case 0: // None of prediction
for ($count = 0; $count < $rows; $count++) {
$output .= chr($predictor);
$output .= substr($data, $offset, $bytesPerRow);
$offset += $bytesPerRow;
}
break;
case 1: // Sub prediction
for ($count = 0; $count < $rows; $count++) {
$output .= chr($predictor);
$lastSample = array_fill(0, $bytesPerSample, 0);
for ($count2 = 0; $count2 < $bytesPerRow; $count2++) {
$newByte = ord($data[$offset++]);
// Note. chr() automatically cuts input to 8 bit
$output .= chr($newByte - $lastSample[$count2 % $bytesPerSample]);
$lastSample[$count2 % $bytesPerSample] = $newByte;
}
}
break;
case 2: // Up prediction
$lastRow = array_fill(0, $bytesPerRow, 0);
for ($count = 0; $count < $rows; $count++) {
$output .= chr($predictor);
for ($count2 = 0; $count2 < $bytesPerRow; $count2++) {
$newByte = ord($data[$offset++]);
// Note. chr() automatically cuts input to 8 bit
$output .= chr($newByte - $lastRow[$count2]);
$lastRow[$count2] = $newByte;
}
}
break;
case 3: // Average prediction
$lastRow = array_fill(0, $bytesPerRow, 0);
for ($count = 0; $count < $rows; $count++) {
$output .= chr($predictor);
$lastSample = array_fill(0, $bytesPerSample, 0);
for ($count2 = 0; $count2 < $bytesPerRow; $count2++) {
$newByte = ord($data[$offset++]);
// Note. chr() automatically cuts input to 8 bit
$output .= chr($newByte - floor(( $lastSample[$count2 % $bytesPerSample] + $lastRow[$count2])/2));
$lastSample[$count2 % $bytesPerSample] = $lastRow[$count2] = $newByte;
}
}
break;
case 4: // Paeth prediction
$lastRow = array_fill(0, $bytesPerRow, 0);
$currentRow = array();
for ($count = 0; $count < $rows; $count++) {
$output .= chr($predictor);
$lastSample = array_fill(0, $bytesPerSample, 0);
for ($count2 = 0; $count2 < $bytesPerRow; $count2++) {
$newByte = ord($data[$offset++]);
// Note. chr() automatically cuts input to 8 bit
$output .= chr($newByte - self::_paeth( $lastSample[$count2 % $bytesPerSample],
$lastRow[$count2],
($count2 - $bytesPerSample < 0)?
0 : $lastRow[$count2 - $bytesPerSample] ));
$lastSample[$count2 % $bytesPerSample] = $currentRow[$count2] = $newByte;
}
$lastRow = $currentRow;
}
break;
}
return $output;
}
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Unknown prediction algorithm - ' . $predictor . '.' );
}
/**
* Convert stream data according to the filter params set after decoding.
*
* @param string $data
* @param array $params
* @return string
*/
protected static function _applyDecodeParams($data, $params) {
$predictor = self::_getPredictorValue($params);
$colors = self::_getColorsValue($params);
$bitsPerComponent = self::_getBitsPerComponentValue($params);
$columns = self::_getColumnsValue($params);
/** None of prediction */
if ($predictor == 1) {
return $data;
}
/** TIFF Predictor 2 */
if ($predictor == 2) {
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Not implemented yet' );
}
/**
* PNG prediction
* Prediction code is duplicated on each row.
* Thus all cases can be brought to one
*/
if ($predictor == 10 || /** None of prediction */
$predictor == 11 || /** Sub prediction */
$predictor == 12 || /** Up prediction */
$predictor == 13 || /** Average prediction */
$predictor == 14 || /** Paeth prediction */
$predictor == 15 /** Optimal prediction */) {
$bitsPerSample = $bitsPerComponent*$colors;
$bytesPerSample = ceil($bitsPerSample/8);
$bytesPerRow = ceil($bitsPerSample*$columns/8);
$rows = ceil(strlen($data)/($bytesPerRow + 1));
$output = '';
$offset = 0;
$lastRow = array_fill(0, $bytesPerRow, 0);
for ($count = 0; $count < $rows; $count++) {
$lastSample = array_fill(0, $bytesPerSample, 0);
switch (ord($data[$offset++])) {
case 0: // None of prediction
$output .= substr($data, $offset, $bytesPerRow);
for ($count2 = 0; $count2 < $bytesPerRow && $offset < strlen($data); $count2++) {
$lastSample[$count2 % $bytesPerSample] = $lastRow[$count2] = ord($data[$offset++]);
}
break;
case 1: // Sub prediction
for ($count2 = 0; $count2 < $bytesPerRow && $offset < strlen($data); $count2++) {
$decodedByte = (ord($data[$offset++]) + $lastSample[$count2 % $bytesPerSample]) & 0xFF;
$lastSample[$count2 % $bytesPerSample] = $lastRow[$count2] = $decodedByte;
$output .= chr($decodedByte);
}
break;
case 2: // Up prediction
for ($count2 = 0; $count2 < $bytesPerRow && $offset < strlen($data); $count2++) {
$decodedByte = (ord($data[$offset++]) + $lastRow[$count2]) & 0xFF;
$lastSample[$count2 % $bytesPerSample] = $lastRow[$count2] = $decodedByte;
$output .= chr($decodedByte);
}
break;
case 3: // Average prediction
for ($count2 = 0; $count2 < $bytesPerRow && $offset < strlen($data); $count2++) {
$decodedByte = (ord($data[$offset++]) +
floor(( $lastSample[$count2 % $bytesPerSample] + $lastRow[$count2])/2)
) & 0xFF;
$lastSample[$count2 % $bytesPerSample] = $lastRow[$count2] = $decodedByte;
$output .= chr($decodedByte);
}
break;
case 4: // Paeth prediction
$currentRow = array();
for ($count2 = 0; $count2 < $bytesPerRow && $offset < strlen($data); $count2++) {
$decodedByte = (ord($data[$offset++]) +
self::_paeth($lastSample[$count2 % $bytesPerSample],
$lastRow[$count2],
($count2 - $bytesPerSample < 0)?
0 : $lastRow[$count2 - $bytesPerSample])
) & 0xFF;
$lastSample[$count2 % $bytesPerSample] = $currentRow[$count2] = $decodedByte;
$output .= chr($decodedByte);
}
$lastRow = $currentRow;
break;
default:
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Unknown prediction tag.');
}
}
return $output;
}
require_once 'Zend/Pdf/Exception.php';
throw new Zend_Pdf_Exception('Unknown prediction algorithm - ' . $predictor . '.' );
}
}
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