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Update script to fit the newest version of the initial python script
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<?php | |
class iOSPNGNormalizer | |
{ | |
public static function fix($filename, $destfilename = null) | |
{ | |
try { | |
$handle = fopen($filename, "rb"); | |
$oldPNG = fread($handle, filesize($filename)); | |
fclose($handle); | |
$newPng = self::getNormalizedPNG($oldPNG); | |
if (is_null($destfilename)) | |
$destfilename = $filename; | |
file_put_contents($destfilename, $newPng); | |
} catch (Exception $exc) { | |
return $exc->getMessage(); | |
} | |
return true; | |
} | |
public static function getNormalizedPNG($oldPNG) | |
{ | |
// Check if the orginal png needs to be processed | |
$im = @imagecreatefromstring($oldPNG); | |
if($im !== false) | |
return $oldPNG; | |
$pngheader = "\x89PNG\r\n\x1a\n"; | |
if (substr($oldPNG, 0, 8) != $pngheader) | |
return; | |
$newPNG = substr($oldPNG, 0, 8); | |
$chunkPos = 8; | |
$idatAcc = ""; | |
$breakLoop = false; | |
while ($chunkPos < strlen($oldPNG)) { | |
$skip = false; | |
// Reading chunk | |
$chunkLength = unpack("N", substr($oldPNG, $chunkPos, $chunkPos + 4)); | |
$chunkLength = array_shift($chunkLength); | |
$chunkType = substr($oldPNG, $chunkPos + 4, 4); | |
$chunkData = substr($oldPNG, $chunkPos + 8, $chunkLength); | |
$chunkCRC = unpack("N", substr($oldPNG, $chunkPos + $chunkLength + 8, 4)); | |
$chunkCRC = array_shift($chunkCRC); | |
$chunkPos += $chunkLength + 12; | |
// Reading header chunk | |
if ($chunkType == 'IHDR') { | |
$width = unpack("N", substr($chunkData, 0, 4)); | |
$width = array_shift($width); | |
$height = unpack("N", substr($chunkData, 4, 8)); | |
$height = array_shift($height); | |
} | |
// Parsing the image chunk | |
if ($chunkType == "IDAT") { | |
// Store the chunk data for later decompression | |
$idatAcc .= $chunkData; | |
$skip = true; | |
} | |
// Removing CgBI chunk | |
if ($chunkType == "CgBI") { | |
$skip = true; | |
} | |
// Add all accumulated IDATA chunks | |
if ($chunkType == 'IEND') { | |
try { | |
// Uncompressing the image chunk | |
$bufSize = $width * $height * 4 + $height; | |
$chunkData = zlib_decode($idatAcc, $bufSize); | |
} catch (Exception $exc) { | |
return $oldPNG; // already optimized | |
} | |
$chunkType = "IDAT"; | |
// Swapping red & blue bytes for each pixel | |
$newdata = ""; | |
for ($y = 0; $y < $height; $y++) { | |
$i = strlen($newdata); | |
$newdata .= $chunkData[$i]; | |
for ($x = 0; $x < $width; $x++) { | |
$i = strlen($newdata); | |
$newdata .= $chunkData[$i + 2]; | |
$newdata .= $chunkData[$i + 1]; | |
$newdata .= $chunkData[$i + 0]; | |
$newdata .= $chunkData[$i + 3]; | |
} | |
} | |
// Compressing the image chunk | |
$chunkData = $newdata; | |
$chunkData = zlib_encode($chunkData, ZLIB_ENCODING_DEFLATE); | |
$chunkLength = strlen($chunkData); | |
$chunkCRC = crc32($chunkType . $chunkData); | |
$chunkCRC = ($chunkCRC + 0x100000000) % 0x100000000; | |
$breakLoop = true; | |
} | |
if (!$skip) { | |
$newPNG .= pack("N", $chunkLength); | |
$newPNG .= $chunkType; | |
if ($chunkLength > 0) { | |
$newPNG .= $chunkData; | |
$newPNG .= pack("N", $chunkCRC); | |
} | |
} | |
if ($breakLoop) break; | |
} | |
return $newPNG; | |
} | |
} |
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Thanks ! I almost forget that I write this 😄