{

use PsrLogAwareTrait;

/**

private $mpdf;

/**

private $otl;

/**

private $cssManager;

/**

private $sizeConverter;

/**

private $colorConverter;

/**

private $colorModeConverter;

/**

private $cache;

/**

private $guesser;

/**

private $failedImages;

/**

private $bmp;

/**

private $wmf;

/**

private $languageToFont;

/**

public $scriptToLanguage;

/**

private $assetFetcher;

public function __construct(

Mpdf $mpdf,

Otl $otl,

CssManager $cssManager,

SizeConverter $sizeConverter,

ColorConverter $colorConverter,

ColorModeConverter $colorModeConverter,

Cache $cache,

LanguageToFontInterface $languageToFont,

ScriptToLanguageInterface $scriptToLanguage,

AssetFetcher $assetFetcher,

LoggerInterface $logger

) {

$this->mpdf = $mpdf;

$this->otl = $otl;

$this->cssManager = $cssManager;

$this->sizeConverter = $sizeConverter;

$this->colorConverter = $colorConverter;

$this->colorModeConverter = $colorModeConverter;

$this->cache = $cache;

$this->languageToFont = $languageToFont;

$this->scriptToLanguage = $scriptToLanguage;

$this->assetFetcher = $assetFetcher;

$this->logger = $logger;

$this->guesser = new ImageTypeGuesser();

$this->failedImages = [];

}

public function getImage(&$file, $firstTime = true, $allowvector = true, $orig_srcpath = false, $interpolation = false)

{

// mPDF 6

// firsttime i.e. whether to add to this->images - use false when calling iteratively

// Image Data passed directly as var:varname

$type = null;

$data = '';

if (preg_match('/var:\s*(.*)/', $file, $v)) {

if (!isset($this->mpdf->imageVars[$v[1]])) {

return $this->imageError($file, $firstTime, 'Unknown image variable');

}

$data = $this->mpdf->imageVars[$v[1]];

$file = md5($data);

}

if (preg_match('/data:image\/(gif|jpe?g|png|webp|svg\+xml);base64,(.*)/', $file, $v)) {

$type = $v[1];

$data = base64_decode($v[2]);

$file = md5($data);

}

// mPDF 5.7.4 URLs

if ($firstTime && $file && strpos($file, 'data:') !== 0) {

$file = str_replace(' ', '%20', $file);

}

if ($firstTime && $orig_srcpath) {

// If orig_srcpath is a relative file path (and not a URL), then it needs to be URL decoded

if (strpos($orig_srcpath, 'data:') !== 0) {

$orig_srcpath = str_replace(' ', '%20', $orig_srcpath);

}

if (!preg_match('/^(http|ftp)/', $orig_srcpath)) {

$orig_srcpath = $this->urldecodeParts($orig_srcpath);

}

}

if ($orig_srcpath && isset($this->mpdf->images[$orig_srcpath])) {

$file = $orig_srcpath;

return $this->mpdf->images[$orig_srcpath];

}

if (isset($this->mpdf->images[$file])) {

return $this->mpdf->images[$file];

}

if ($orig_srcpath && isset($this->mpdf->formobjects[$orig_srcpath])) {

$file = $orig_srcpath;

return $this->mpdf->formobjects[$file];

}

if (isset($this->mpdf->formobjects[$file])) {

return $this->mpdf->formobjects[$file];

}

if ($firstTime && isset($this->failedImages[$file])) { // Save re-trying image URL's which have already failed

return $this->imageError($file, $firstTime, '');

}

if (!$data) {

try {

$data = $this->assetFetcher->fetchDataFromPath($file, $orig_srcpath);

} catch (\Mpdf\Exception\AssetFetchingException $e) {

return $this->imageError($orig_srcpath, $firstTime, $e->getMessage());

}

}

if (!$data) {

return $this->imageError($file, $firstTime, 'Could not find image file');

}

if ($type === null) {

$type = $this->guesser->guess($data);

}

if ($type === 'svg' || $type === 'svg+xml') {

if (!$allowvector) {

return $this->imageError($file, $firstTime, 'SVG image file not supported in this context');

}

return $this->processSvg($data, $file, $firstTime);

}

if ($type === 'wmf') {

if (!$allowvector) {

return $this->imageError($file, $firstTime, 'WMF image file not supported in this context');

}

return $this->processWmf($data, $file, $firstTime);

}

if ($type === 'webp') {

// Convert webp images to JPG and treat them as such

$data = $this->processWebp($data, $file, $firstTime);

$type = 'jpeg';

}

// JPEG

if ($type === 'jpeg' || $type === 'jpg') {

return $this->processJpg($data, $file, $firstTime, $interpolation);

}

if ($type === 'png') {

return $this->processPng($data, $file, $firstTime, $interpolation);

}

if ($type === 'gif') { // GIF

return $this->processGif($data, $file, $firstTime, $interpolation);

}

if ($type === 'bmp') {

return $this->processBmp($data, $file, $firstTime, $interpolation);

}

return $this->processUnknownType($data, $file, $firstTime, $interpolation);

}

private function convertImage(&$data, $colspace, $targetcs, $w, $h, $dpi, $mask, $gamma_correction = false, $pngcolortype = false)

{

if (!function_exists('gd_info')) {

return $this->imageError('', false, 'GD library needed to parse image files');

}

if ($this->mpdf->PDFA || $this->mpdf->PDFX) {

$mask = false;

}

$im = @imagecreatefromstring($data);

$info = [];

$bpc = ord(substr($data, 24, 1));

if ($im) {

$imgdata = '';

$mimgdata = '';

$minfo = [];

// mPDF 6 Gamma correction

// Need to extract alpha channel info before imagegammacorrect (which loses the data)

if ($mask) { // i.e. $pngalpha for PNG

// mPDF 6

if ($colspace === 'Indexed') { // generate Alpha channel values from tRNS - only from PNG

//Read transparency info

$transparency = '';

$p = strpos($data, 'tRNS');

if ($p) {

$n = $this->fourBytesToInt(substr($data, $p - 4, 4));

$transparency = substr($data, $p + 4, $n);

// ord($transparency[$index]) = the alpha value for that index

// generate alpha channel

for ($ypx = 0; $ypx < $h; ++$ypx) {

for ($xpx = 0; $xpx < $w; ++$xpx) {

$colorindex = imagecolorat($im, $xpx, $ypx);

if ($colorindex >= $n) {

$alpha = 255;

} else {

$alpha = ord($transparency[$colorindex]);

} // 0-255

$mimgdata .= chr($alpha);

}

}

}

} elseif ($pngcolortype === 0 || $pngcolortype === 2) { // generate Alpha channel values from tRNS

// Get transparency as array of RGB

$p = strpos($data, 'tRNS');

if ($p) {

$trns = '';

$n = $this->fourBytesToInt(substr($data, $p - 4, 4));

$t = substr($data, $p + 4, $n);

if ($colspace === 'DeviceGray') { // ct===0

$trns = [$this->translateValue(substr($t, 0, 2), $bpc)];

} else /* $colspace=='DeviceRGB' */ { // ct==2

$trns = [];

$trns[0] = $this->translateValue(substr($t, 0, 2), $bpc);

$trns[1] = $this->translateValue(substr($t, 2, 2), $bpc);

$trns[2] = $this->translateValue(substr($t, 4, 2), $bpc);

}

// generate alpha channel

for ($ypx = 0; $ypx < $h; ++$ypx) {

for ($xpx = 0; $xpx < $w; ++$xpx) {

$rgb = imagecolorat($im, $xpx, $ypx);

$r = ($rgb >> 16) & 0xFF;

$g = ($rgb >> 8) & 0xFF;

$b = $rgb & 0xFF;

if ($colspace === 'DeviceGray' && $b == $trns[0]) {

$alpha = 0;

} elseif ($r == $trns[0] && $g == $trns[1] && $b == $trns[2]) {

$alpha = 0;

} // ct==2

else {

$alpha = 255;

}

$mimgdata .= chr($alpha);

}

}

}

} else {

for ($i = 0; $i < $h; $i++) {

for ($j = 0; $j < $w; $j++) {

$rgb = imagecolorat($im, $j, $i);

$alpha = ($rgb & 0x7F000000) >> 24;

if ($alpha < 127) {

$mimgdata .= chr(255 - ($alpha * 2));

} else {

$mimgdata .= chr(0);

}

}

}

}

}

// mPDF 6 Gamma correction

if ($gamma_correction) {

imagegammacorrect($im, $gamma_correction, 2.2);

}

// Read transparency info

$trns = [];

$trnsrgb = false;

if (!$this->mpdf->PDFA && !$this->mpdf->PDFX && !$mask) { // mPDF 6 added NOT mask

$p = strpos($data, 'tRNS');

if ($p) {

$n = $this->fourBytesToInt(substr($data, ($p - 4), 4));

$t = substr($data, $p + 4, $n);

if ($colspace === 'DeviceGray') { // ct===0

$trns = [$this->translateValue(substr($t, 0, 2), $bpc)];

} elseif ($colspace === 'DeviceRGB') { // ct==2

$trns[0] = $this->translateValue(substr($t, 0, 2), $bpc);

$trns[1] = $this->translateValue(substr($t, 2, 2), $bpc);

$trns[2] = $this->translateValue(substr($t, 4, 2), $bpc);

$trnsrgb = $trns;

if ($targetcs === 'DeviceCMYK') {

$col = $this->colorModeConverter->rgb2cmyk([3, $trns[0], $trns[1], $trns[2]]);

$c1 = (int) ($col[1] * 2.55);

$c2 = (int) ($col[2] * 2.55);

$c3 = (int) ($col[3] * 2.55);

$c4 = (int) ($col[4] * 2.55);

$trns = [$c1, $c2, $c3, $c4];

} elseif ($targetcs === 'DeviceGray') {

$c = (int) (($trns[0] * .21) + ($trns[1] * .71) + ($trns[2] * .07));

$trns = [$c];

}

} else { // Indexed

$pos = strpos($t, chr(0));

if (is_int($pos)) {

$pal = imagecolorsforindex($im, $pos);

$r = $pal['red'];

$g = $pal['green'];

$b = $pal['blue'];

$trns = [$r, $g, $b]; // ****

$trnsrgb = $trns;

if ($targetcs === 'DeviceCMYK') {

$col = $this->colorModeConverter->rgb2cmyk([3, $r, $g, $b]);

$c1 = (int) ($col[1] * 2.55);

$c2 = (int) ($col[2] * 2.55);

$c3 = (int) ($col[3] * 2.55);

$c4 = (int) ($col[4] * 2.55);

$trns = [$c1, $c2, $c3, $c4];

} elseif ($targetcs === 'DeviceGray') {

$c = (int) (($r * .21) + ($g * .71) + ($b * .07));

$trns = [$c];

}

}

}

}

}

for ($i = 0; $i < $h; $i++) {

for ($j = 0; $j < $w; $j++) {

$rgb = imagecolorat($im, $j, $i);

$r = ($rgb >> 16) & 0xFF;

$g = ($rgb >> 8) & 0xFF;

$b = $rgb & 0xFF;

if ($colspace === 'Indexed') {

$pal = imagecolorsforindex($im, $rgb);

$r = $pal['red'];

$g = $pal['green'];

$b = $pal['blue'];

}

if ($targetcs === 'DeviceCMYK') {

$col = $this->colorModeConverter->rgb2cmyk([3, $r, $g, $b]);

$c1 = (int) ($col[1] * 2.55);

$c2 = (int) ($col[2] * 2.55);

$c3 = (int) ($col[3] * 2.55);

$c4 = (int) ($col[4] * 2.55);

if ($trnsrgb) {

// original pixel was not set as transparent but processed color does match

if ($trnsrgb !== [$r, $g, $b] && $trns === [$c1, $c2, $c3, $c4]) {

if ($c4 === 0) {

$c4 = 1;

} else {

$c4--;

}

}

}

$imgdata .= chr($c1) . chr($c2) . chr($c3) . chr($c4);

} elseif ($targetcs === 'DeviceGray') {

$c = (int) (($r * .21) + ($g * .71) + ($b * .07));

if ($trnsrgb) {

// original pixel was not set as transparent but processed color does match

if ($trnsrgb !== [$r, $g, $b] && $trns === [$c]) {

if ($c === 0) {

$c = 1;

} else {

$c--;

}

}

}

$imgdata .= chr($c);

} elseif ($targetcs === 'DeviceRGB') {

$imgdata .= chr($r) . chr($g) . chr($b);

}

}

}

if ($targetcs === 'DeviceGray') {

$ncols = 1;

} elseif ($targetcs === 'DeviceRGB') {

$ncols = 3;

} elseif ($targetcs === 'DeviceCMYK') {

$ncols = 4;

}

$imgdata = $this->gzCompress($imgdata);

$info = ['w' => $w, 'h' => $h, 'cs' => $targetcs, 'bpc' => 8, 'f' => 'FlateDecode', 'data' => $imgdata, 'type' => 'png',

'parms' => '/DecodeParms <</Colors ' . $ncols . ' /BitsPerComponent 8 /Columns ' . $w . '>>'];

if ($dpi) {

$info['set-dpi'] = $dpi;

}

if ($mask) {

$mimgdata = $this->gzCompress($mimgdata);

$minfo = ['w' => $w, 'h' => $h, 'cs' => 'DeviceGray', 'bpc' => 8, 'f' => 'FlateDecode', 'data' => $mimgdata, 'type' => 'png',

'parms' => '/DecodeParms <</Colors ' . $ncols . ' /BitsPerComponent 8 /Columns ' . $w . '>>'];

if ($dpi) {

$minfo['set-dpi'] = $dpi;

}

$tempfile = '_tempImgPNG' . md5($data) . random_int(1, 10000) . '.png';

$imgmask = count($this->mpdf->images) + 1;

$minfo['i'] = $imgmask;

$this->mpdf->images[$tempfile] = $minfo;

$info['masked'] = $imgmask;

} elseif ($trns) {

$info['trns'] = $trns;

}

$this->destroyImage($im);

}

return $info;

}

private function jpgHeaderFromString(&$data)

{

$p = 4;

$p += $this->twoBytesToInt(substr($data, $p, 2)); // Length of initial marker block

$marker = substr($data, $p, 2);

while ($marker !== chr(255) . chr(192) && $marker !== chr(255) . chr(194) && $marker !== chr(255) . chr(193) && $p < strlen($data)) {

// Start of frame marker (FFC0) (FFC1) or (FFC2)

$p += $this->twoBytesToInt(substr($data, $p + 2, 2)) + 2; // Length of marker block

$marker = substr($data, $p, 2);

}

if ($marker !== chr(255) . chr(192) && $marker !== chr(255) . chr(194) && $marker !== chr(255) . chr(193)) {

return false;

}

return substr($data, $p + 2, 10);

}

private function jpgDataFromHeader($hdr)

{

$bpc = ord(substr($hdr, 2, 1));

if (!$bpc) {

$bpc = 8;

}

$h = $this->twoBytesToInt(substr($hdr, 3, 2));

$w = $this->twoBytesToInt(substr($hdr, 5, 2));

$channels = ord(substr($hdr, 7, 1));

if ($channels === 3) {

$colspace = 'DeviceRGB';

} elseif ($channels === 4) {

$colspace = 'DeviceCMYK';

} else {

$colspace = 'DeviceGray';

}

return [$w, $h, $colspace, $bpc, $channels];

}

/**

private function translateValue($s, $bpc)

{

$n = $this->twoBytesToInt($s);

if ($bpc == 16) {

$n = ($n >> 8);

}

//elseif ($bpc==4) { $n = ($n << 2); }

//elseif ($bpc==2) { $n = ($n << 4); }

return $n;

}

/**

private function fourBytesToInt($s)

{

return (ord($s[0]) << 24) + (ord($s[1]) << 16) + (ord($s[2]) << 8) + ord($s[3]);

}

/**

private function twoBytesToInt($s)

{

return (ord(substr($s, 0, 1)) << 8) + ord(substr($s, 1, 1));

}

private function gzCompress($data)

{

if (!function_exists('gzcompress')) {

throw new \Mpdf\MpdfException('gzcompress is not available. install ext-zlib extension.');

}

return gzcompress($data);

}

/**

private function imageError($file, $firstTime, $msg)

{

$this->failedImages[$file] = true;

if ($firstTime && ($this->mpdf->showImageErrors || $this->mpdf->debug)) {

throw new \Mpdf\MpdfImageException(sprintf('%s (%s)', $msg, substr($file, 0, 256)));

}

$this->logger->warning(sprintf('%s (%s)', $msg, $file), ['context' => LogContext::IMAGES]);

}

/**

private function urldecodeParts($url)

{

$file = $url;

$query = '';

if (preg_match('/[?]/', $url)) {

$bits = preg_split('/[?]/', $url, 2);

$file = $bits[0];

$query = '?' . $bits[1];

}

$file = rawurldecode($file);

$query = urldecode($query);

return $file . $query;

}

public function processJpg($data, $file, $firstTime, $interpolation)

{

$ppUx = 0;

$hdr = $this->jpgHeaderFromString($data);

if (!$hdr) {

return $this->imageError($file, $firstTime, 'Error parsing JPG header');

}

$a = $this->jpgDataFromHeader($hdr);

$channels = (int) $a[4];

$j = strpos($data, 'JFIF');

if ($j) {

// Read resolution

$unitSp = ord(substr($data, $j + 7, 1));

if ($unitSp > 0) {

$ppUx = $this->twoBytesToInt(substr($data, $j + 8, 2)); // horizontal pixels per meter, usually set to zero

if ($unitSp === 2) { // = dots per cm (if == 1 set as dpi)

$ppUx = round($ppUx / 10 * 25.4);

}

}

}

if ($a[2] === 'DeviceCMYK' && ($this->mpdf->restrictColorSpace === 2 || ($this->mpdf->PDFA && $this->mpdf->restrictColorSpace !== 3))) {

// convert to RGB image

if (!function_exists('gd_info')) {

throw new \Mpdf\MpdfException(sprintf('JPG image may not use CMYK color space (%s).', $file));

}

if ($this->mpdf->PDFA && !$this->mpdf->PDFAauto) {

$this->mpdf->PDFAXwarnings[] = sprintf('JPG image "%s" may not use CMYK color space. Image converted to RGB. The colour profile was altered', $file);

}

$im = @imagecreatefromstring($data);

if ($im) {

$tempfile = $this->cache->tempFilename('_tempImgPNG' . md5($file) . random_int(1, 10000) . '.png');

imageinterlace($im, false);

$check = @imagepng($im, $tempfile);

if (!$check) {

return $this->imageError($file, $firstTime, sprintf('Error creating temporary file "%s" when using GD library to parse JPG (CMYK) image', $tempfile));

}

// $info = $this->getImage($tempfile, false);

$data = file_get_contents($tempfile);

$info = $this->processPng($data, $tempfile, false, $interpolation);

if (!$info) {

return $this->imageError($file, $firstTime, sprintf('Error parsing temporary file "%s" created with GD library to parse JPG (CMYK) image', $tempfile));

}

$this->destroyImage($im);

unlink($tempfile);

$info['type'] = 'jpg';

if ($firstTime) {

$info['i'] = count($this->mpdf->images) + 1;

$info['interpolation'] = $interpolation; // mPDF 6

$this->mpdf->images[$file] = $info;

}

return $info;

}

return $this->imageError($file, $firstTime, 'Error creating GD image file from JPG(CMYK) image');

}

if ($a[2] === 'DeviceRGB' && ($this->mpdf->PDFX || $this->mpdf->restrictColorSpace === 3)) {

// Convert to CMYK image stream - nominally returned as type='png'

$info = $this->convertImage($data, $a[2], 'DeviceCMYK', $a[0], $a[1], $ppUx, false);

if (($this->mpdf->PDFA && !$this->mpdf->PDFAauto) || ($this->mpdf->PDFX && !$this->mpdf->PDFXauto)) {

$this->mpdf->PDFAXwarnings[] = sprintf('JPG image may not use RGB color space - %s - (Image converted to CMYK. NB This will alter the colour profile of the image.)', $file);

}

} elseif (($a[2] === 'DeviceRGB' || $a[2] === 'DeviceCMYK') && $this->mpdf->restrictColorSpace === 1) {

// Convert to Grayscale image stream - nominally returned as type='png'

$info = $this->convertImage($data, $a[2], 'DeviceGray', $a[0], $a[1], $ppUx, false);

} else {

// mPDF 6 Detect Adobe APP14 Tag

//$pos = strpos($data, "\xFF\xEE\x00\x0EAdobe\0");

//if ($pos !== false) {

//}

// mPDF 6 ICC profile

$offset = 0;

$icc = [];

while (($pos = strpos($data, "ICC_PROFILE\0", $offset)) !== false) {

// get ICC sequence length

$length = $this->twoBytesToInt(substr($data, $pos - 2, 2)) - 16;

$sn = max(1, ord($data[$pos + 12]));

$nom = max(1, ord($data[$pos + 13]));

$icc[$sn - 1] = substr($data, $pos + 14, $length);

$offset = ($pos + 14 + $length);

}

// order and compact ICC segments

if (count($icc) > 0) {

ksort($icc);

$icc = implode('', $icc);

if (substr($icc, 36, 4) !== 'acsp') {

// invalid ICC profile

$icc = false;

}

$input = substr($icc, 16, 4);

$output = substr($icc, 20, 4);

// Ignore Color profiles for conversion to other colorspaces e.g. CMYK/Lab

if ($input !== 'RGB ' || $output !== 'XYZ ') {

$icc = false;

}

} else {

$icc = false;

}

$info = ['w' => $a[0], 'h' => $a[1], 'cs' => $a[2], 'bpc' => $a[3], 'f' => 'DCTDecode', 'data' => $data, 'type' => 'jpg', 'ch' => $channels, 'icc' => $icc];

if ($ppUx) {

$info['set-dpi'] = $ppUx;

}

}

if (!$info) {

return $this->imageError($file, $firstTime, 'Error parsing or converting JPG image');

}

if ($firstTime) {

$info['i'] = count($this->mpdf->images) + 1;

$info['interpolation'] = $interpolation; // mPDF 6

$this->mpdf->images[$file] = $info;

}

return $info;

}

public function processPng($data, $file, $firstTime, $interpolation)

{

$ppUx = 0;

// Check signature

if (strpos($data, chr(137) . 'PNG' . chr(13) . chr(10) . chr(26) . chr(10)) !== 0) {

return $this->imageError($file, $firstTime, 'Error parsing PNG identifier');

}

// Read header chunk

if (substr($data, 12, 4) !== 'IHDR') {

return $this->imageError($file, $firstTime, 'Incorrect PNG file (no IHDR block found)');

}

$w = $this->fourBytesToInt(substr($data, 16, 4));

$h = $this->fourBytesToInt(substr($data, 20, 4));

$bpc = ord(substr($data, 24, 1));

$errpng = false;

$pngalpha = false;

$channels = 0;

// if($bpc>8) { $errpng = 'not 8-bit depth'; } // mPDF 6 Allow through to be handled as native PNG

$ct = ord(substr($data, 25, 1));

if ($ct === 0) {

$colspace = 'DeviceGray';

$channels = 1;

} elseif ($ct === 2) {

$colspace = 'DeviceRGB';

$channels = 3;

} elseif ($ct === 3) {

$colspace = 'Indexed';

$channels = 1;

} elseif ($ct === 4) {

$colspace = 'DeviceGray';

$channels = 1;

$errpng = 'alpha channel';

$pngalpha = true;

} else {

$colspace = 'DeviceRGB';

$channels = 3;

$errpng = 'alpha channel';

$pngalpha = true;

}

if ($ct < 4 && strpos($data, 'tRNS') !== false) {

$errpng = 'transparency';

$pngalpha = true;

} // mPDF 6

if ($ct === 3 && strpos($data, 'iCCP') !== false) {

$errpng = 'indexed plus ICC';

} // mPDF 6

// $pngalpha is used as a FLAG of any kind of transparency which COULD be tranferred to an alpha channel

// incl. single-color tarnsparency, depending which type of handling occurs later

if (ord(substr($data, 26, 1)) !== 0) {

$errpng = 'compression method';

} // only 0 should be specified

if (ord(substr($data, 27, 1)) !== 0) {

$errpng = 'filter method';

} // only 0 should be specified

if (ord(substr($data, 28, 1)) !== 0) {

$errpng = 'interlaced file';

}

$j = strpos($data, 'pHYs');

if ($j) {

//Read resolution

$unitSp = ord(substr($data, $j + 12, 1));

if ($unitSp === 1) {

$ppUx = $this->fourBytesToInt(substr($data, $j + 4, 4)); // horizontal pixels per meter, usually set to zero

$ppUx = round($ppUx / 1000 * 25.4);

}

}

// mPDF 6 Gamma correction

$gamma = 0;

$gAMA = 0;

$j = strpos($data, 'gAMA');

if ($j && strpos($data, 'sRGB') === false) { // sRGB colorspace - overrides gAMA

$gAMA = $this->fourBytesToInt(substr($data, $j + 4, 4)); // Gamma value times 100000

$gAMA /= 100000;

// http://www.libpng.org/pub/png/spec/1.2/PNG-Encoders.html

// "If the source file's gamma value is greater than 1.0, it is probably a display system exponent,..."

// ("..and you should use its reciprocal for the PNG gamma.")

//if ($gAMA > 1) { $gAMA = 1/$gAMA; }

// (Some) Applications seem to ignore it... appearing how it was probably intended

// Test Case - image(s) on http://www.w3.org/TR/CSS21/intro.html - PNG has gAMA set as 1.45454

// Probably unintentional as mentioned above and should be 0.45454 which is 1 / 2.2

// Tested on Windows PC

// Firefox and Opera display gray as 234 (correct, but looks wrong)

// IE9 and Safari display gray as 193 (incorrect but looks right)

// See test different gamma chunks at http://www.libpng.org/pub/png/pngsuite-all-good.html

}

if ($gAMA) {

$gamma = 1 / $gAMA;

}

// Don't need to apply gamma correction if == default i.e. 2.2

if ($gamma > 2.15 && $gamma < 2.25) {

$gamma = 0;

}

// NOT supported at present

//$j = strpos($data,'sRGB'); // sRGB colorspace - overrides gAMA

//$j = strpos($data,'cHRM'); // Chromaticity and Whitepoint

// $firstTime added mPDF 6 so when PNG Grayscale with alpha using resrtictcolorspace to CMYK

// the alpha channel is sent through as secondtime as Indexed and should not be converted to CMYK

if ($firstTime && ($colspace === 'DeviceRGB' || $colspace === 'Indexed') && ($this->mpdf->PDFX || $this->mpdf->restrictColorSpace === 3)) {

// Convert to CMYK image stream - nominally returned as type='png'

$info = $this->convertImage($data, $colspace, 'DeviceCMYK', $w, $h, $ppUx, $pngalpha, $gamma, $ct); // mPDF 5.7.2 Gamma correction

if (($this->mpdf->PDFA && !$this->mpdf->PDFAauto) || ($this->mpdf->PDFX && !$this->mpdf->PDFXauto)) {

$this->mpdf->PDFAXwarnings[] = sprintf('PNG image may not use RGB color space - %s - (Image converted to CMYK. NB This will alter the colour profile of the image.)', $file);

}

} elseif ($firstTime && ($colspace === 'DeviceRGB' || $colspace === 'Indexed') && $this->mpdf->restrictColorSpace === 1) {

// $firstTime added mPDF 6 so when PNG Grayscale with alpha using resrtictcolorspace to CMYK

// the alpha channel is sent through as secondtime as Indexed and should not be converted to CMYK

// Convert to Grayscale image stream - nominally returned as type='png'

$info = $this->convertImage($data, $colspace, 'DeviceGray', $w, $h, $ppUx, $pngalpha, $gamma, $ct); // mPDF 5.7.2 Gamma correction

} elseif (($this->mpdf->PDFA || $this->mpdf->PDFX) && $pngalpha) {

// Remove alpha channel

if ($this->mpdf->restrictColorSpace === 1) { // Grayscale

$info = $this->convertImage($data, $colspace, 'DeviceGray', $w, $h, $ppUx, $pngalpha, $gamma, $ct); // mPDF 5.7.2 Gamma correction

} elseif ($this->mpdf->restrictColorSpace === 3) { // CMYK

$info = $this->convertImage($data, $colspace, 'DeviceCMYK', $w, $h, $ppUx, $pngalpha, $gamma, $ct); // mPDF 5.7.2 Gamma correction

} elseif ($this->mpdf->PDFA) { // RGB

$info = $this->convertImage($data, $colspace, 'DeviceRGB', $w, $h, $ppUx, $pngalpha, $gamma, $ct); // mPDF 5.7.2 Gamma correction

}

if (($this->mpdf->PDFA && !$this->mpdf->PDFAauto) || ($this->mpdf->PDFX && !$this->mpdf->PDFXauto)) {

$this->mpdf->PDFAXwarnings[] = sprintf('Transparency (alpha channel) not permitted in PDFA or PDFX files - %s - (Image converted to one without transparency.)', $file);

}

} elseif ($firstTime && ($errpng || $pngalpha || $gamma)) { // mPDF 5.7.2 Gamma correction

$gd = function_exists('gd_info') ? gd_info() : [];

if (!isset($gd['PNG Support'])) {

return $this->imageError($file, $firstTime, sprintf('GD library with PNG support required for image (%s)', $errpng));

}

$im = @imagecreatefromstring($data);

if (!$im) {

return $this->imageError($file, $firstTime, sprintf('Error creating GD image from PNG file (%s)', $errpng));

}

$w = imagesx($im);

$h = imagesy($im);

$tempfile = $this->cache->tempFilename('_tempImgPNG' . md5($file) . bin2hex(random_bytes(6)) . '.png');

// Alpha channel set (including using tRNS for Paletted images)

if ($pngalpha) {

if ($this->mpdf->PDFA) {

throw new \Mpdf\MpdfException(sprintf('PDFA1-b does not permit images with alpha channel transparency (%s).', $file));

}

$imgalpha = imagecreate($w, $h);

// generate gray scale pallete

for ($c = 0; $c < 256; ++$c) {

imagecolorallocate($imgalpha, $c, $c, $c);

}

// mPDF 6

if ($colspace === 'Indexed') { // generate Alpha channel values from tRNS

// Read transparency info

$p = strpos($data, 'tRNS');

if ($p) {

$n = $this->fourBytesToInt(substr($data, $p - 4, 4));

$transparency = substr($data, $p + 4, $n);

// ord($transparency[$index]) = the alpha value for that index

// generate alpha channel

for ($ypx = 0; $ypx < $h; ++$ypx) {

for ($xpx = 0; $xpx < $w; ++$xpx) {

$colorindex = imagecolorat($im, $xpx, $ypx);

if ($colorindex >= $n) {

$alpha = 255;

} else {

$alpha = ord($transparency[$colorindex]);

} // 0-255

if ($alpha > 0) {

imagesetpixel($imgalpha, $xpx, $ypx, $alpha);

}

}

}

}