/**
* Get width and height from the bmp header.
*
* @param File $image
* @param string $filename
* @return array
*/
function getImageSize($image, $filename)
{
$f = fopen($filename, 'rb');
if (!$f) {
return false;
}
$header = fread($f, 54);
fclose($f);
// Extract binary form of width and height from the header
$w = substr($header, 18, 4);
$h = substr($header, 22, 4);
// Convert the unsigned long 32 bits (little endian):
try {
$w = wfUnpack('V', $w, 4);
$h = wfUnpack('V', $h, 4);
} catch (Exception $e) {
return false;
}
return [$w[1], $h[1]];
}
/**
* Metadata for a given XCF file
*
* Will return false if file magic signature is not recognized
* @author Hexmode
* @author Hashar
*
* @param string $filename Full path to a XCF file
* @return bool|array Metadata Array just like PHP getimagesize()
*/
static function getXCFMetaData($filename)
{
# Decode master structure
$f = fopen($filename, 'rb');
if (!$f) {
return false;
}
# The image structure always starts at offset 0 in the XCF file.
# So we just read it :-)
$binaryHeader = fread($f, 26);
fclose($f);
/**
* Master image structure:
*
* byte[9] "gimp xcf " File type magic
* byte[4] version XCF version
* "file" - version 0
* "v001" - version 1
* "v002" - version 2
* byte 0 Zero-terminator for version tag
* uint32 width With of canvas
* uint32 height Height of canvas
* uint32 base_type Color mode of the image; one of
* 0: RGB color
* 1: Grayscale
* 2: Indexed color
* (enum GimpImageBaseType in libgimpbase/gimpbaseenums.h)
*/
try {
$header = wfUnpack("A9magic" . "/a5version" . "/Nwidth" . "/Nheight" . "/Nbase_type", $binaryHeader);
} catch (Exception $mwe) {
return false;
}
# Check values
if ($header['magic'] !== 'gimp xcf') {
wfDebug(__METHOD__ . " '{$filename}' has invalid magic signature.\n");
return false;
}
# TODO: we might want to check for sane values of width and height
wfDebug(__METHOD__ . ": canvas size of '{$filename}' is {$header['width']} x {$header['height']} px\n");
return $header;
}
/**
* Metadata for a given XCF file
*
* Will return false if file magic signature is not recognized
* @author Hexmode
* @author Hashar
*
* @param string $filename Full path to a XCF file
* @return bool|array metadata array just like PHP getimagesize()
*/
static function getXCFMetaData($filename)
{
# Decode master structure
$f = fopen($filename, 'rb');
if (!$f) {
return false;
}
# The image structure always starts at offset 0 in the XCF file.
# So we just read it :-)
$binaryHeader = fread($f, 26);
fclose($f);
# Master image structure:
#
# byte[9] "gimp xcf " File type magic
# byte[4] version XCF version
# "file" - version 0
# "v001" - version 1
# "v002" - version 2
# byte 0 Zero-terminator for version tag
# uint32 width With of canvas
# uint32 height Height of canvas
# uint32 base_type Color mode of the image; one of
# 0: RGB color
# 1: Grayscale
# 2: Indexed color
# (enum GimpImageBaseType in libgimpbase/gimpbaseenums.h)
try {
$header = wfUnpack("A9magic" . "/a5version" . "/Nwidth" . "/Nheight" . "/Nbase_type", $binaryHeader);
} catch (MWException $mwe) {
return false;
}
# Check values
if ($header['magic'] !== 'gimp xcf') {
wfDebug(__METHOD__ . " '{$filename}' has invalid magic signature.\n");
return false;
}
# TODO: we might want to check for sane values of width and height
wfDebug(__METHOD__ . ": canvas size of '{$filename}' is {$header['width']} x {$header['height']} px\n");
# Forge a return array containing metadata information just like getimagesize()
# See PHP documentation at: http://www.php.net/getimagesize
$metadata = array();
$metadata[0] = $header['width'];
$metadata[1] = $header['height'];
$metadata[2] = null;
# IMAGETYPE constant, none exist for XCF.
$metadata[3] = sprintf('height="%s" width="%s"', $header['height'], $header['width']);
$metadata['mime'] = 'image/x-xcf';
$metadata['channels'] = null;
$metadata['bits'] = 8;
# Always 8-bits per color
assert('7 == count($metadata); # return array must contains 7 elements just like getimagesize() return');
return $metadata;
}
/**
* This reads the photoshop image resource.
* Currently it only compares the iptc/iim hash
* with the stored hash, which is used to determine the precedence
* of the iptc data. In future it may extract some other info, like
* url of copyright license.
*
* This should generally be called by BitmapMetadataHandler::doApp13()
*
* @param string $app13 Photoshop psir app13 block from jpg.
* @throws MWException (It gets caught next level up though)
* @return string If the iptc hash is good or not. One of 'iptc-no-hash',
* 'iptc-good-hash', 'iptc-bad-hash'.
*/
public static function doPSIR($app13)
{
if (!$app13) {
throw new MWException("No App13 segment given");
}
// First compare hash with real thing
// 0x404 contains IPTC, 0x425 has hash
// This is used to determine if the iptc is newer than
// the xmp data, as xmp programs update the hash,
// where non-xmp programs don't.
$offset = 14;
// skip past PHOTOSHOP 3.0 identifier. should already be checked.
$appLen = strlen($app13);
$realHash = "";
$recordedHash = "";
// the +12 is the length of an empty item.
while ($offset + 12 <= $appLen) {
$valid = true;
if (substr($app13, $offset, 4) !== '8BIM') {
// its supposed to be 8BIM
// but apparently sometimes isn't esp. in
// really old jpg's
$valid = false;
}
$offset += 4;
$id = substr($app13, $offset, 2);
// id is a 2 byte id number which identifies
// the piece of info this record contains.
$offset += 2;
// some record types can contain a name, which
// is a pascal string 0-padded to be an even
// number of bytes. Most times (and any time
// we care) this is empty, making it two null bytes.
$lenName = ord(substr($app13, $offset, 1)) + 1;
// we never use the name so skip it. +1 for length byte
if ($lenName % 2 == 1) {
$lenName++;
}
// pad to even.
$offset += $lenName;
// now length of data (unsigned long big endian)
$lenData = wfUnpack('Nlen', substr($app13, $offset, 4), 4);
// PHP can take issue with very large unsigned ints and make them negative.
// Which should never ever happen, as this has to be inside a segment
// which is limited to a 16 bit number.
if ($lenData['len'] < 0) {
throw new MWException("Too big PSIR (" . $lenData['len'] . ')');
}
$offset += 4;
// 4bytes length field;
// this should not happen, but check.
if ($lenData['len'] + $offset > $appLen) {
throw new MWException("PSIR data too long. (item length=" . $lenData['len'] . "; offset={$offset}; total length={$appLen})");
}
if ($valid) {
switch ($id) {
case "":
// IPTC block
$realHash = md5(substr($app13, $offset, $lenData['len']), true);
break;
case "%":
$recordedHash = substr($app13, $offset, $lenData['len']);
break;
}
}
// if odd, add 1 to length to account for
// null pad byte.
if ($lenData['len'] % 2 == 1) {
$lenData['len']++;
}
$offset += $lenData['len'];
}
if (!$realHash || !$recordedHash) {
return 'iptc-no-hash';
} elseif ($realHash === $recordedHash) {
return 'iptc-good-hash';
} else {
/*$realHash !== $recordedHash */
return 'iptc-bad-hash';
}
}
