152 lines
4.6 KiB
PHP
152 lines
4.6 KiB
PHP
<?php namespace ProcessWire;
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// parsePng is a part of FPDF v1.81 - 2015-12-20
|
|
// Author: Olivier PLATHEY
|
|
// http://fpdf.org/
|
|
//
|
|
// Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
// of this software to use, copy, modify, distribute, sublicense, and/or sell
|
|
// copies of the software, and to permit persons to whom the software is furnished
|
|
// to do so.
|
|
//
|
|
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED.
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////
|
|
// PNG Inspector
|
|
// original code from FPDF modified in April 2016 by Horst Nogajski
|
|
// to be used for png image inspection in ProcessWire 3+ (http://processwire.com/)
|
|
///////////////////////////////////////////////////////////////////////////////////////////////////
|
|
class PWPNG {
|
|
public $info = array();
|
|
public $errors = array();
|
|
protected $extended;
|
|
public function __construct($extended = false) {
|
|
$this->extended = $extended;
|
|
}
|
|
public function loadFile($lpszFileName) {
|
|
// READ FILE
|
|
if(!($fh = @fopen($lpszFileName, 'rb'))) {
|
|
$this->Error('Can\'t open image file: '.basename($lpszFileName));
|
|
return false;
|
|
}
|
|
$ret = (false === $this->_parsepngstream($fh, basename($lpszFileName))) ? false : true;
|
|
fclose($fh);
|
|
return $ret;
|
|
}
|
|
protected function _parsepngstream($f, $file) {
|
|
// Check signature
|
|
if($this->_readstream($f, 8) != chr(137) . 'PNG' . chr(13) . chr(10) . chr(26) . chr(10)) {
|
|
$this->Error('Not a PNG file: '.$file);
|
|
return false;
|
|
}
|
|
// Read header chunk
|
|
$this->_readstream($f, 4);
|
|
if($this->_readstream($f, 4) != 'IHDR') {
|
|
$this->Error('Incorrect PNG file: '.$file);
|
|
return false;
|
|
}
|
|
$w = $this->_readint($f);
|
|
$h = $this->_readint($f);
|
|
$bpc = ord($this->_readstream($f, 1));
|
|
//if($bpc > 8) {
|
|
// $this->Error('16-bit depth not supported: '.$file);
|
|
//}
|
|
$ct = ord($this->_readstream($f, 1));
|
|
if($ct == 0 || $ct == 4) {
|
|
$colspace = 'DeviceGray';
|
|
} else if($ct == 2 || $ct == 6) {
|
|
$colspace = 'DeviceRGB';
|
|
} else if($ct == 3) {
|
|
$colspace = 'Indexed';
|
|
} else {
|
|
$this->Error('Unknown color type: '.$file);
|
|
$colspace = '';
|
|
}
|
|
if(ord($this->_readstream($f, 1)) != 0) $this->Error('Unknown compression method: '.$file);
|
|
if(ord($this->_readstream($f, 1)) != 0) $this->Error('Unknown filter method: '.$file);
|
|
$interlaced = ord($this->_readstream($f, 1)) != 0 ? true : false;
|
|
$this->_readstream($f, 4);
|
|
$dp = '/Predictor 15 /Colors '.($colspace=='DeviceRGB' ? 3 : 1).' /BitsPerComponent '.$bpc.' /Columns '.$w;
|
|
// Scan chunks looking for palette, transparency and image data
|
|
// http://www.w3.org/TR/2003/REC-PNG-20031110/#table53
|
|
// http://www.libpng.org/pub/png/book/chapter11.html#png.ch11.div.6
|
|
$pal = '';
|
|
$trns = '';
|
|
$counter = 0;
|
|
do {
|
|
$n = $this->_readint($f);
|
|
$counter += $n;
|
|
$type = $this->_readstream($f,4);
|
|
|
|
if($type=='PLTE') {
|
|
|
|
// Read palette
|
|
$pal = $this->_readstream($f, $n);
|
|
$this->_readstream($f,4);
|
|
|
|
} else if($type == 'tRNS') {
|
|
|
|
// Read transparency info
|
|
$t = $this->_readstream($f,$n);
|
|
if($ct == 0) {
|
|
$trns = array(ord(substr($t,1,1)));
|
|
} else if($ct == 2) {
|
|
$trns = array(ord(substr($t, 1, 1)), ord(substr($t, 3, 1)), ord(substr($t, 5, 1)));
|
|
} else {
|
|
$pos = strpos($t, chr(0));
|
|
if($pos !== false) $trns = array($pos);
|
|
}
|
|
$this->_readstream($f, 4);
|
|
|
|
} else if($type == 'IEND' || $type == 'IDAT' || $counter >= 2048) {
|
|
|
|
break;
|
|
|
|
} else {
|
|
|
|
$this->_readstream($f,$n+4);
|
|
}
|
|
} while($n);
|
|
if($colspace == 'Indexed' && empty($pal)) $this->Error('Missing palette in '.$file);
|
|
|
|
$this->info = array(
|
|
'width' => $w,
|
|
'height' => $h,
|
|
'colspace' => $colspace,
|
|
'channels' => $ct,
|
|
'bits' => $bpc,
|
|
'dp' => $dp,
|
|
'palette' => (function_exists('mb_convert_encoding') ? mb_convert_encoding($pal, 'UTF-8', 'ISO-8859-1') : $pal),
|
|
'trans' => $trns,
|
|
'alpha' => $ct >= 4 ? true : false,
|
|
'interlace' => $interlaced,
|
|
'errors' => $this->errors
|
|
);
|
|
|
|
return true;
|
|
}
|
|
|
|
protected function _readstream($f, $n) {
|
|
// Read n bytes from stream
|
|
$res = '';
|
|
while($n > 0 && !feof($f)) {
|
|
$s = fread($f, $n);
|
|
if($s === false) {
|
|
$this->Error('Error while reading stream');
|
|
return '';
|
|
}
|
|
$n -= strlen($s);
|
|
$res .= $s;
|
|
}
|
|
if($n > 0) $this->Error('Unexpected end of stream');
|
|
return $res;
|
|
}
|
|
protected function _readint($f) {
|
|
// Read a 4-byte integer from stream
|
|
$a = unpack('Ni',$this->_readstream($f,4));
|
|
return $a['i'];
|
|
}
|
|
protected function Error($msg) {
|
|
$this->errors[] = $msg;
|
|
}
|
|
|
|
}
|