4 Copyright(c) 2008-2010 Internet Archive. Software license AGPL version 3.
6 This file is part of BookReader. The full source code can be found at GitHub:
7 http://github.com/openlibrary/bookreader
9 The canonical short name of an image type is the same as in the MIME type.
10 For example both .jpeg and .jpg are considered to have type "jpeg" since
11 the MIME type is "image/jpeg".
13 BookReader is free software: you can redistribute it and/or modify
14 it under the terms of the GNU Affero General Public License as published by
15 the Free Software Foundation, either version 3 of the License, or
16 (at your option) any later version.
18 BookReader is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU Affero General Public License for more details.
23 You should have received a copy of the GNU Affero General Public License
24 along with BookReader. If not, see <http://www.gnu.org/licenses/>.
27 require_once("BookReaderMeta.inc.php");
29 class BookReaderImages
31 public static $MIMES = array('gif' => 'image/gif',
33 'jpg' => 'image/jpeg',
34 'jpeg' => 'image/jpeg',
36 'tif' => 'image/tiff',
37 'tiff' => 'image/tiff');
39 public static $EXTENSIONS = array('gif' => 'gif',
47 // Width when generating thumbnails
48 public static $imageSizes = array(
55 // Keys in the image permalink urls, e.g. http://www.archive.org/download/itemid/page/cover_{keyval}_{keyval}.jpg
56 public static $imageUrlKeys = array(
57 //'r' => 'reduce', // pow of 2 reduction
58 's' => 'scale', // $$$ scale is downscaling factor in BookReaderImages but most people call this "reduce"
68 // Paths to command-line tools
69 var $exiftool = '/petabox/sw/books/exiftool/exiftool';
70 var $kduExpand = '/petabox/sw/bin/kdu_expand';
72 // Name of temporary files, to be cleaned at exit
73 var $tempFiles = array();
76 * Serve an image request that requires looking up the book metadata
80 * - Parse the requested page (e.g. cover_t.jpg, n5_r4.jpg) to determine which page type,
81 * size and format (etc) is being requested
82 * - Determine the leaf number corresponding to the page
83 * - Determine scaling values
84 * - Serve image request now that all information has been gathered
87 function serveLookupRequest($requestEnv) {
88 $brm = new BookReaderMeta();
90 $metadata = $brm->buildMetadata($_REQUEST['id'], $_REQUEST['itemPath'], $_REQUEST['subPrefix'], $_REQUEST['server']);
91 } catch (Exception $e) {
92 $this->BRfatal($e->getMessage());
95 $page = $_REQUEST['page'];
97 // Index of image to return
100 // deal with subPrefix
101 if ($_REQUEST['subPrefix']) {
102 $parts = explode('/', $_REQUEST['subPrefix']);
103 $bookId = $parts[count($parts) - 1 ];
105 $bookId = $_REQUEST['id'];
108 $pageInfo = $this->parsePageRequest($page, $bookId);
110 $basePage = $pageInfo['type'];
117 if (! array_key_exists('titleIndex', $metadata)) {
118 $this->BRfatal("No title page asserted in book");
120 $imageIndex = $metadata['titleIndex'];
123 /* Old 'cover' behaviour where it would show cover 0 if it exists or return 404.
124 Could be re-added as cover0, cover1, etc
126 if (! array_key_exists('coverIndices', $metadata)) {
127 $this->BRfatal("No cover asserted in book");
129 $imageIndex = $metadata['coverIndices'][0]; // $$$ TODO add support for other covers
134 case 'cover': // Show our best guess if cover is requested
136 // Cover page if book was published >= 1950
141 if ( array_key_exists('date', $metadata) && array_key_exists('coverIndices', $metadata) ) {
142 if ($brm->parseYear($metadata['date']) >= 1950) {
143 $imageIndex = $metadata['coverIndices'][0];
147 if (array_key_exists('titleIndex', $metadata)) {
148 $imageIndex = $metadata['titleIndex'];
151 if (array_key_exists('coverIndices', $metadata)) {
152 $imageIndex = $metadata['coverIndices'][0];
161 // Accessible index page
162 $imageIndex = intval($pageInfo['value']);
167 $index = array_search($pageInfo['value'], $metadata['pageNums']);
168 if ($index === FALSE) {
170 $this->BRfatal("Page not found");
174 $imageIndex = $index;
178 // Leaf explicitly specified
179 $leaf = $pageInfo['value'];
183 // Shouldn't be possible
184 $this->BRfatal("Unrecognized page type requested");
189 if (is_null($leaf)) {
190 // Leaf was not explicitly set -- look it up
191 $leaf = $brm->leafForIndex($imageIndex, $metadata['leafNums']);
195 'zip' => $metadata['zip'],
196 'file' => $brm->imageFilePath($leaf, $metadata['subPrefix'], $metadata['imageFormat']),
197 'ext' => 'jpg', // XXX should pass through ext
200 // remove non-passthrough keys from pageInfo
201 unset($pageInfo['type']);
202 unset($pageInfo['value']);
204 // add pageinfo to request
205 $requestEnv = array_merge($pageInfo, $requestEnv);
207 // Return image data - will check privs
208 $this->serveRequest($requestEnv);
213 * Returns a page image when all parameters such as the image stack location are
218 * Get info about requested image (input)
219 * Get info about requested output format
220 * Determine processing parameters
223 * Clean up temporary files
225 function serveRequest($requestEnv) {
227 // Process some of the request parameters
228 $zipPath = $requestEnv['zip'];
229 $file = $requestEnv['file'];
231 $ext = $requestEnv['ext'];
236 if (isset($requestEnv['callback'])) {
237 // validate callback is valid JS identifier (only)
238 $callback = $requestEnv['callback'];
239 $identifierPatt = '/^[[:alpha:]$_]([[:alnum:]$_])*$/';
240 if (! preg_match($identifierPatt, $callback)) {
241 $this->BRfatal('Invalid callback');
247 if ( !file_exists($zipPath) ) {
248 $this->BRfatal('Image stack does not exist at ' . $zipPath);
250 // Make sure the image stack is readable - return 403 if not
251 $this->checkPrivs($zipPath);
254 // Get the image size and depth
255 $imageInfo = $this->getImageInfo($zipPath, $file);
258 foreach (array('x', 'y', 'w', 'h') as $key) {
259 if (array_key_exists($key, $requestEnv)) {
260 $region[$key] = $requestEnv[$key];
263 $regionDimensions = $this->getRegionDimensions($imageInfo, $region);
268 print_r($regionDimensions);
271 // Output json if requested
272 if ('json' == $ext) {
273 // $$$ we should determine the output size first based on requested scale
274 $this->outputJSON($imageInfo, $callback); // $$$ move to BookReaderRequest
278 // Unfortunately kakadu requires us to know a priori if the
279 // output file should be .ppm or .pgm. By decompressing to
280 // .bmp kakadu will write a file we can consistently turn into
281 // .pnm. Really kakadu should support .pnm as the file output
282 // extension and automatically write ppm or pgm format as
284 $this->decompressToBmp = true; // $$$ shouldn't be necessary if we use file info to determine output format
285 if ($this->decompressToBmp) {
286 $stdoutLink = '/tmp/stdout.bmp';
288 $stdoutLink = '/tmp/stdout.ppm';
291 $fileExt = strtolower(pathinfo($file, PATHINFO_EXTENSION));
293 // Rotate is currently only supported for jp2 since it does not add server load
294 $allowedRotations = array("0", "90", "180", "270");
295 $rotate = $requestEnv['rotate'];
296 if ( !in_array($rotate, $allowedRotations) ) {
300 // Image conversion options
302 $jpegOptions = '-quality 75';
304 // The pbmreduce reduction factor produces an image with dimension 1/n
305 // The kakadu reduction factor produces an image with dimension 1/(2^n)
307 // We interpret the requested size and scale, look at image format, and determine the
308 // actual scaling to be returned to the client. We generally return the largest
309 // power of 2 reduction that is larger than the requested size in order to reduce
310 // image processing load on our cluster. The client should then scale to their final
313 // Set scale from height or width if set
314 if (isset($requestEnv['height'])) {
315 $powReduce = $this->nearestPow2Reduce($requestEnv['height'], $imageInfo['height']);
316 $scale = pow(2, $powReduce);
317 } else if (isset($requestEnv['width'])) {
318 $powReduce = $this->nearestPow2Reduce($requestEnv['width'], $imageInfo['width']);
319 $scale = pow(2, $powReduce);
322 // Set scale from named size (e.g. 'large') if set
323 $size = $requestEnv['size'];
324 if ( $size && array_key_exists($size, self::$imageSizes)) {
325 $srcRatio = floatval($imageInfo['width']) / floatval($imageInfo['height']);
328 $dimension = 'width';
330 $dimension = 'height';
332 $powReduce = $this->nearestPow2Reduce(self::$imageSizes[$size], $imageInfo[$dimension]);
333 $scale = pow(2, $powReduce);
336 // No named size - use explicit scale, if given
337 $scale = $requestEnv['scale'];
341 $powReduce = $this->nearestPow2ForScale($scale);
342 // ensure integer scale
343 $scale = pow(2, $powReduce);
347 // Override depending on source image format
348 // $$$ consider doing a 302 here instead, to make better use of the browser cache
349 // Limit scaling for 1-bit images. See https://bugs.edge.launchpad.net/bookreader/+bug/486011
350 if (1 == $imageInfo['bits']) {
356 // Hard limit so there are some black pixels to use!
364 if (!file_exists($stdoutLink))
366 system('ln -s /dev/stdout ' . $stdoutLink);
369 putenv('LD_LIBRARY_PATH=/petabox/sw/lib/kakadu');
371 $unzipCmd = $this->getUnarchiveCommand($zipPath, $file);
373 $decompressCmd = $this->getDecompressCmd($imageInfo['type'], $powReduce, $rotate, $scale, $stdoutLink);
375 // Non-integer scaling is currently disabled on the cluster
376 // if (isset($_REQUEST['height'])) {
377 // $cmd .= " | pnmscale -height {$_REQUEST['height']} ";
382 $compressCmd = ' | pnmtopng ' . $pngOptions;
388 $compressCmd = ' | pnmtojpeg ' . $jpegOptions;
389 $ext = 'jpeg'; // for matching below
394 if (($ext == $fileExt) && ($scale == 1) && ($rotate === "0")) {
395 // Just pass through original data if same format and size
398 $cmd = $unzipCmd . $decompressCmd . $compressCmd;
403 $filenameForClient = $this->filenameForClient($file, $ext);
405 $headers = array('Content-type: '. self::$MIMES[$ext],
406 'Cache-Control: max-age=15552000',
407 'Content-disposition: inline; filename=' . $filenameForClient);
412 if (! $this->passthruIfSuccessful($headers, $cmd, $errorMessage)) { // $$$ move to BookReaderRequest
413 // $$$ automated reporting
414 trigger_error('BookReader Processing Error: ' . $cmd . ' -- ' . $errorMessage, E_USER_WARNING);
416 // Try some content-specific recovery
418 if ($imageInfo['type'] == 'jp2') {
419 $records = $this->getJp2Records($zipPath, $file);
420 if (array_key_exists('Clevels', $records)) {
421 $maxReduce = intval($records['Clevels']);
422 trigger_error("BookReader using max reduce $maxReduce from jp2 records");
427 $powReduce = min($powReduce, $maxReduce);
428 $reduce = pow(2, $powReduce);
430 $cmd = $unzipCmd . $this->getDecompressCmd($imageInfo['type'], $powReduce, $rotate, $scale, $stdoutLink) . $compressCmd;
431 trigger_error('BookReader rerunning with new cmd: ' . $cmd, E_USER_WARNING);
432 if ($this->passthruIfSuccessful($headers, $cmd, $errorMessage)) { // $$$ move to BookReaderRequest
436 trigger_error('BookReader fallback image processing also failed: ' . $errorMessage, E_USER_WARNING);
441 $this->BRfatal('Problem processing image - command failed');
448 function getUnarchiveCommand($archivePath, $file)
450 $lowerPath = strtolower($archivePath);
451 if (preg_match('/\.([^\.]+)$/', $lowerPath, $matches)) {
452 $suffix = $matches[1];
454 if ($suffix == 'zip') {
456 . escapeshellarg($archivePath)
457 . ' ' . escapeshellarg($file);
458 } else if ($suffix == 'tar') {
459 return ' ( 7z e -so '
460 . escapeshellarg($archivePath)
461 . ' ' . escapeshellarg($file) . ' 2>/dev/null ) ';
463 $this->BRfatal('Incompatible archive format');
467 $this->BRfatal('Bad image stack path');
470 $this->BRfatal('Bad image stack path or archive format');
475 * Returns the image type associated with the file extension.
477 function imageExtensionToType($extension)
480 if (array_key_exists($extension, self::$EXTENSIONS)) {
481 return self::$EXTENSIONS[$extension];
483 $this->BRfatal('Unknown image extension');
488 * Get the image information. The returned associative array fields will
489 * vary depending on the image type. The basic keys are width, height, type
492 function getImageInfo($zipPath, $file)
494 return $this->getImageInfoFromExif($zipPath, $file); // this is fast
497 $fileExt = strtolower(pathinfo($file, PATHINFO_EXTENSION));
498 $type = imageExtensionToType($fileExt);
502 return getImageInfoFromJp2($zipPath, $file);
505 return getImageInfoFromExif($zipPath, $file);
510 // Get the records of of JP2 as returned by kdu_expand
511 function getJp2Records($zipPath, $file)
514 $cmd = $this->getUnarchiveCommand($zipPath, $file)
515 . ' | ' . $this->kduExpand
516 . ' -no_seek -quiet -i /dev/stdin -record /dev/stdout';
520 foreach ($output as $line) {
521 $elems = explode("=", $line, 2);
522 if (1 == count($elems)) {
523 // delimiter not found
526 $records[$elems[0]] = $elems[1];
533 * Get the image width, height and depth using the EXIF information.
535 function getImageInfoFromExif($zipPath, $file)
538 // We look for all the possible tags of interest then act on the
539 // ones presumed present based on the file type
540 $tagsToGet = ' -ImageWidth -ImageHeight -FileType' // all formats
541 . ' -BitsPerComponent -ColorSpace' // jp2
542 . ' -BitDepth' // png
543 . ' -BitsPerSample'; // tiff
545 $cmd = $this->getUnarchiveCommand($zipPath, $file)
546 . ' | '. $this->exiftool . ' -S -fast' . $tagsToGet . ' -';
550 foreach ($output as $line) {
551 $keyValue = explode(": ", $line);
552 $tags[$keyValue[0]] = $keyValue[1];
555 $width = intval($tags["ImageWidth"]);
556 $height = intval($tags["ImageHeight"]);
557 $type = strtolower($tags["FileType"]);
561 $bits = intval($tags["BitsPerComponent"]);
564 $bits = intval($tags["BitsPerSample"]);
570 $bits = intval($tags["BitDepth"]);
573 $this->BRfatal("Unsupported image type $type for file $file in $zipPath");
578 $retval = Array('width' => $width, 'height' => $height,
579 'bits' => $bits, 'type' => $type);
585 * Output JSON given the imageInfo associative array
587 function outputJSON($imageInfo, $callback)
589 header('Content-type: text/plain');
590 $jsonOutput = json_encode($imageInfo);
592 $jsonOutput = $callback . '(' . $jsonOutput . ');';
597 function getDecompressCmd($imageType, $powReduce, $rotate, $scale, $stdoutLink) {
599 switch ($imageType) {
602 " | " . $this->kduExpand . " -no_seek -quiet -reduce $powReduce -rotate $rotate -i /dev/stdin -o " . $stdoutLink;
603 if ($this->decompressToBmp) {
604 // We suppress output since bmptopnm always outputs on stderr
605 $decompressCmd .= ' | (bmptopnm 2>/dev/null)';
610 // We need to create a temporary file for tifftopnm since it cannot
611 // work on a pipe (the file must be seekable).
612 // We use the BookReaderTiff prefix to give a hint in case things don't
614 $tempFile = tempnam("/tmp", "BookReaderTiff");
615 array_push($this->tempFiles, $tempFile);
617 // $$$ look at bit depth when reducing
619 ' > ' . $tempFile . ' ; tifftopnm ' . $tempFile . ' 2>/dev/null' . $this->reduceCommand($scale);
623 $decompressCmd = ' | ( jpegtopnm 2>/dev/null ) ' . $this->reduceCommand($scale);
627 $decompressCmd = ' | ( pngtopnm 2>/dev/null ) ' . $this->reduceCommand($scale);
631 $this->BRfatal('Unknown image type: ' . $imageType);
634 return $decompressCmd;
637 // If the command has its initial output on stdout the headers will be emitted followed
638 // by the stdout output. If initial output is on stderr an error message will be
642 // true - if command emits stdout and has zero exit code
643 // false - command has initial output on stderr or non-zero exit code
644 // &$errorMessage - error string if there was an error
646 // $$$ Tested with our command-line image processing. May be deadlocks for
648 function passthruIfSuccessful($headers, $cmd, &$errorMessage)
653 $descriptorspec = array(
654 0 => array("pipe", "r"), // stdin is a pipe that the child will read from
655 1 => array("pipe", "w"), // stdout is a pipe that the child will write to
656 2 => array("pipe", "w"), // stderr is a pipe to write to
662 $process = proc_open($cmd, $descriptorspec, $pipes, $cwd, $env);
664 if (is_resource($process)) {
665 // $pipes now looks like this:
666 // 0 => writeable handle connected to child stdin
667 // 1 => readable handle connected to child stdout
668 // 2 => readable handle connected to child stderr
674 // check whether we get input first on stdout or stderr
675 $read = array($stdout, $stderr);
679 $numChanged = stream_select($read, $write, $except, NULL); // $$$ no timeout
680 if (false === $numChanged) {
682 $errorMessage = 'Select failed';
684 error_log('BookReader select failed!');
686 if (in_array($stderr, $read)) {
687 // Either content in stderr, or stderr is closed (could read 0 bytes)
688 $error = stream_get_contents($stderr);
691 $errorMessage = $error;
698 // It is important that you close any pipes before calling
699 // proc_close in order to avoid a deadlock
700 proc_close($process);
706 $output = fopen('php://output', 'w');
707 foreach($headers as $header) {
710 stream_copy_to_stream($pipes[1], $output);
711 fclose($output); // okay since tied to special php://output
720 // It is important that you close any pipes before calling
721 // proc_close in order to avoid a deadlock
722 $cmdRet = proc_close($process);
725 $errorMessage .= "Command failed with result code " . $cmdRet;
731 function BRfatal($string) {
733 throw new Exception("Image error: $string");
736 // Returns true if using a power node
737 // XXX change to "on red box" - not working for new Xeon
738 function onPowerNode() {
739 exec("lspci | fgrep -c Realtek", $output, $return);
740 if ("0" != $output[0]) {
743 exec("egrep -q AMD /proc/cpuinfo", $output, $return);
751 function reduceCommand($scale) {
753 if ($this->onPowerNode()) {
754 return ' | pnmscale -reduce ' . $scale . ' 2>/dev/null ';
756 return ' | pnmscale -nomix -reduce ' . $scale . ' 2>/dev/null ';
763 function checkPrivs($filename) {
764 // $$$ we assume here that requests for the title, cover or preview
765 // come in via BookReaderPreview.php which will be re-run with
766 // privileges after we return the 403
767 if (!is_readable($filename)) {
768 header('HTTP/1.1 403 Forbidden');
773 // Given file path (inside archive) and output file extension, return a filename
774 // suitable for Content-disposition header
775 function filenameForClient($filePath, $ext) {
776 $pathParts = pathinfo($filePath);
777 if ('jpeg' == $ext) {
780 return $pathParts['filename'] . '.' . $ext;
783 // Returns the nearest power of 2 reduction factor that results in a larger image
784 function nearestPow2Reduce($desiredDimension, $sourceDimension) {
785 $ratio = floatval($sourceDimension) / floatval($desiredDimension);
786 return $this->nearestPow2ForScale($ratio);
789 // Returns nearest power of 2 reduction factor that results in a larger image
790 function nearestPow2ForScale($scale) {
791 $scale = intval($scale);
795 $binStr = decbin($scale); // convert to binary string. e.g. 5 -> '101'
796 return strlen($binStr) - 1;
800 * Parses a page request like "page5_r2.jpg" or "cover_t.jpg" to corresponding
801 * page type, size, reduce, and format
803 function parsePageRequest($pageRequest, $bookPrefix) {
805 // Will hold parsed results
809 $pageRequest = strtolower($pageRequest);
811 // Pull off extension
812 if (preg_match('#(.*)\.([^.]+)$#', $pageRequest, $matches) === 1) {
813 $pageRequest = $matches[1];
814 $extension = $matches[2];
815 if ($extension == 'jpeg') {
821 $pageInfo['extension'] = $extension;
824 $parts = explode('_', $pageRequest);
826 // Remove book prefix if it was included (historical)
827 if ($parts[0] == $bookPrefix) {
831 if (count($parts) === 0) {
832 $this->BRfatal('No page type specified');
834 $page = array_shift($parts);
840 'preview' => 'single',
845 // Look for known page types
846 foreach ( $pageTypes as $pageName => $kind ) {
847 if ( preg_match('#^(' . $pageName . ')(.*)#', $page, $matches) === 1 ) {
848 $pageInfo['type'] = $matches[1];
851 $pageInfo['value'] = $matches[2];
854 $pageInfo['value'] = intval($matches[2]);
862 if ( !array_key_exists('type', $pageInfo) ) {
863 $this->BRfatal('Unrecognized page type');
866 // Look for other known parts
867 foreach ($parts as $part) {
868 if ( array_key_exists($part, self::$imageSizes) ) {
869 $pageInfo['size'] = $part;
873 // Key must be alpha, value must start with digit and contain digits, alpha, ',' or '.'
874 // Should prevent injection of strange values into the redirect to datanode
875 if ( preg_match('#^([a-z]+)(\d[a-z0-9,.]*)#', $part, $matches) === 0) {
881 $value = $matches[2];
883 if ( array_key_exists($key, self::$imageUrlKeys) ) {
884 $pageInfo[self::$imageUrlKeys[$key]] = $value;
888 // If we hit here, was unrecognized (no action)
894 function getRegionDimensions($sourceDimensions, $regionDimensions) {
895 // Return region dimensions as { 'x' => xOffset, 'y' => yOffset, 'w' => width, 'h' => height }
896 // in terms of full resolution image.
897 // Note: this will clip the returned dimensions to fit within the source image
900 if (array_key_exists('x', $regionDimensions)) {
901 $sourceX = intAmount($regionDimensions['x'], $sourceDimensions['width']);
903 $sourceX = $this->clamp(0, $sourceDimensions['width'] - 2, $sourceX); // Allow at least one pixel
906 if (array_key_exists('y', $regionDimensions)) {
907 $sourceY = intAmount($regionDimensions['y'], $sourceDimensions['height']);
909 $sourceY = $this->clamp(0, $sourceDimensions['height'] - 2, $sourceY); // Allow at least one pixel
911 $sourceWidth = $sourceDimensions['width'] - $sourceX;
912 if (array_key_exists('w', $regionDimensions)) {
913 $sourceWidth = intAmount($regionDimensions['w'], $sourceDimensions['width']);
915 $sourceWidth = $this->clamp(1, max(1, $sourceDimensions['width'] - $sourceX), $sourceWidth);
917 $sourceHeight = $sourceDimensions['height'] - $sourceY;
918 if (array_key_exists('h', $regionDimensions)) {
919 $sourceHeight = intAmount($regionDimensions['h'], $sourceDimensions['height']);
921 $sourceHeight = $this->clamp(1, max(1, $sourceDimensions['height'] - $sourceY), $sourceHeight);
923 return array('x' => $sourceX, 'y' => $sourceY, 'w' => $sourceWidth, 'h' => $sourceHeight);
926 function getRegionDimensionsAsFloat($sourceDimensions, $regionDimensions) {
927 // Return region dimensions as { 'x' => xOffset, 'y' => yOffset, 'w' => width, 'h' => height }
928 // in terms of full resolution image.
929 // Note: this will clip the returned dimensions to fit within the source image
932 if (array_key_exists('x', $regionDimensions)) {
933 $sourceX = floatAmount($regionDimensions['x'], $sourceDimensions['width']);
935 $sourceX = $this->clamp(0.0, 1.0, $sourceX);
938 if (array_key_exists('y', $regionDimensions)) {
939 $sourceY = floatAmount($regionDimensions['y'], $sourceDimensions['height']);
941 $sourceY = $this->clamp(0.0, 1.0, $sourceY); // Allow at least one pixel
943 $sourceWidth = $sourceDimensions['width'] - $sourceX;
944 if (array_key_exists('w', $regionDimensions)) {
945 $sourceWidth = floatAmount($regionDimensions['w'], $sourceDimensions['width']);
947 $sourceWidth = $this->clamp(0.0, 1.0, $sourceWidth);
949 $sourceHeight = $sourceDimensions['height'] - $sourceY;
950 if (array_key_exists('h', $regionDimensions)) {
951 $sourceHeight = floatAmount($regionDimensions['h'], $sourceDimensions['height']);
953 $sourceHeight = $this->clamp(0.0, 1.0, $sourceHeight);
955 return array('x' => $sourceX, 'y' => $sourceY, 'w' => $sourceWidth, 'h' => $sourceHeight);
958 function intAmount($stringValue, $maximum) {
959 // Returns integer amount for string like "5" (5 units) or "0.5" (50%)
960 if (strpos($stringValue, '.') === false) {
961 // No decimal, assume int
962 return intval($stringValue);
965 return floatval($stringValue) * $maximum + 0.5;
968 function floatAmount($stringValue, $maximum) {
969 // Returns float amount (0.0 to 1.0) for string like "0.4" (40%) or "4" (40% if max is 10)
970 if (strpos($stringValue, ".") === false) {
971 // No decimal, assume int value out of maximum
972 return floatval($stringValue) / $maximum;
975 // Given float - just pass through
976 return floatval($stringValue);
979 function clamp($minValue, $maxValue, $observedValue) {
980 if ($observedValue < $minValue) {
984 if ($observedValue > $maxValue) {
988 return $observedValue;
991 // Clean up temporary files and resources
993 foreach($this->tempFiles as $tempFile) {
996 $this->tempFiles = array();