web/wp-admin/includes/image.php
branchwordpress
changeset 109 03b0d1493584
child 132 4d4862461b8d
equal deleted inserted replaced
-1:000000000000 109:03b0d1493584
       
     1 <?php
       
     2 /**
       
     3  * File contains all the administration image manipulation functions.
       
     4  *
       
     5  * @package WordPress
       
     6  * @subpackage Administration
       
     7  */
       
     8 
       
     9 /**
       
    10  * Create a thumbnail from an Image given a maximum side size.
       
    11  *
       
    12  * This function can handle most image file formats which PHP supports. If PHP
       
    13  * does not have the functionality to save in a file of the same format, the
       
    14  * thumbnail will be created as a jpeg.
       
    15  *
       
    16  * @since 1.2.0
       
    17  *
       
    18  * @param mixed $file Filename of the original image, Or attachment id.
       
    19  * @param int $max_side Maximum length of a single side for the thumbnail.
       
    20  * @return string Thumbnail path on success, Error string on failure.
       
    21  */
       
    22 function wp_create_thumbnail( $file, $max_side, $deprecated = '' ) {
       
    23 	$thumbpath = image_resize( $file, $max_side, $max_side );
       
    24 	return apply_filters( 'wp_create_thumbnail', $thumbpath );
       
    25 }
       
    26 
       
    27 /**
       
    28  * Crop an Image to a given size.
       
    29  *
       
    30  * @since 2.1.0
       
    31  *
       
    32  * @param string|int $src_file The source file or Attachment ID.
       
    33  * @param int $src_x The start x position to crop from.
       
    34  * @param int $src_y The start y position to crop from.
       
    35  * @param int $src_w The width to crop.
       
    36  * @param int $src_h The height to crop.
       
    37  * @param int $dst_w The destination width.
       
    38  * @param int $dst_h The destination height.
       
    39  * @param int $src_abs Optional. If the source crop points are absolute.
       
    40  * @param string $dst_file Optional. The destination file to write to.
       
    41  * @return string New filepath on success, String error message on failure.
       
    42  */
       
    43 function wp_crop_image( $src_file, $src_x, $src_y, $src_w, $src_h, $dst_w, $dst_h, $src_abs = false, $dst_file = false ) {
       
    44 	if ( is_numeric( $src_file ) ) // Handle int as attachment ID
       
    45 		$src_file = get_attached_file( $src_file );
       
    46 
       
    47 	$src = wp_load_image( $src_file );
       
    48 
       
    49 	if ( !is_resource( $src ))
       
    50 		return $src;
       
    51 
       
    52 	$dst = imagecreatetruecolor( $dst_w, $dst_h );
       
    53 
       
    54 	if ( $src_abs ) {
       
    55 		$src_w -= $src_x;
       
    56 		$src_h -= $src_y;
       
    57 	}
       
    58 
       
    59 	if (function_exists('imageantialias'))
       
    60 		imageantialias( $dst, true );
       
    61 
       
    62 	imagecopyresampled( $dst, $src, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h );
       
    63 
       
    64 	imagedestroy( $src ); // Free up memory
       
    65 
       
    66 	if ( ! $dst_file )
       
    67 		$dst_file = str_replace( basename( $src_file ), 'cropped-' . basename( $src_file ), $src_file );
       
    68 
       
    69 	$dst_file = preg_replace( '/\\.[^\\.]+$/', '.jpg', $dst_file );
       
    70 
       
    71 	if ( imagejpeg( $dst, $dst_file, apply_filters( 'jpeg_quality', 90, 'wp_crop_image' ) ) )
       
    72 		return $dst_file;
       
    73 	else
       
    74 		return false;
       
    75 }
       
    76 
       
    77 /**
       
    78  * Generate post image attachment meta data.
       
    79  *
       
    80  * @since 2.1.0
       
    81  *
       
    82  * @param int $attachment_id Attachment Id to process.
       
    83  * @param string $file Filepath of the Attached image.
       
    84  * @return mixed Metadata for attachment.
       
    85  */
       
    86 function wp_generate_attachment_metadata( $attachment_id, $file ) {
       
    87 	$attachment = get_post( $attachment_id );
       
    88 
       
    89 	$metadata = array();
       
    90 	if ( preg_match('!^image/!', get_post_mime_type( $attachment )) && file_is_displayable_image($file) ) {
       
    91 		$full_path_file = $file;
       
    92 		$imagesize = getimagesize( $full_path_file );
       
    93 		$metadata['width'] = $imagesize[0];
       
    94 		$metadata['height'] = $imagesize[1];
       
    95 		list($uwidth, $uheight) = wp_shrink_dimensions($metadata['width'], $metadata['height']);
       
    96 		$metadata['hwstring_small'] = "height='$uheight' width='$uwidth'";
       
    97 
       
    98 		// Make the file path relative to the upload dir
       
    99 		if ( ($uploads = wp_upload_dir()) && false === $uploads['error'] ) { // Get upload directory
       
   100 			if ( 0 === strpos($file, $uploads['basedir']) ) {// Check that the upload base exists in the file path
       
   101 				$file = str_replace($uploads['basedir'], '', $file); // Remove upload dir from the file path
       
   102 				$file = ltrim($file, '/');
       
   103 			}
       
   104 		}
       
   105 		$metadata['file'] = $file;
       
   106 
       
   107 		// make thumbnails and other intermediate sizes
       
   108 		$sizes = array('thumbnail', 'medium', 'large');
       
   109 		$sizes = apply_filters('intermediate_image_sizes', $sizes);
       
   110 
       
   111 		foreach ($sizes as $size) {
       
   112 			$resized = image_make_intermediate_size( $full_path_file, get_option("{$size}_size_w"), get_option("{$size}_size_h"), get_option("{$size}_crop") );
       
   113 			if ( $resized )
       
   114 				$metadata['sizes'][$size] = $resized;
       
   115 		}
       
   116 
       
   117 		// fetch additional metadata from exif/iptc
       
   118 		$image_meta = wp_read_image_metadata( $full_path_file );
       
   119 		if ($image_meta)
       
   120 			$metadata['image_meta'] = $image_meta;
       
   121 
       
   122 	}
       
   123 
       
   124 	return apply_filters( 'wp_generate_attachment_metadata', $metadata );
       
   125 }
       
   126 
       
   127 /**
       
   128  * Load an image from a string, if PHP supports it.
       
   129  *
       
   130  * @since 2.1.0
       
   131  *
       
   132  * @param string $file Filename of the image to load.
       
   133  * @return resource The resulting image resource on success, Error string on failure.
       
   134  */
       
   135 function wp_load_image( $file ) {
       
   136 	if ( is_numeric( $file ) )
       
   137 		$file = get_attached_file( $file );
       
   138 
       
   139 	if ( ! file_exists( $file ) )
       
   140 		return sprintf(__('File &#8220;%s&#8221; doesn&#8217;t exist?'), $file);
       
   141 
       
   142 	if ( ! function_exists('imagecreatefromstring') )
       
   143 		return __('The GD image library is not installed.');
       
   144 
       
   145 	// Set artificially high because GD uses uncompressed images in memory
       
   146 	@ini_set('memory_limit', '256M');
       
   147 	$image = imagecreatefromstring( file_get_contents( $file ) );
       
   148 
       
   149 	if ( !is_resource( $image ) )
       
   150 		return sprintf(__('File &#8220;%s&#8221; is not an image.'), $file);
       
   151 
       
   152 	return $image;
       
   153 }
       
   154 
       
   155 /**
       
   156  * Calculated the new dimentions for a downsampled image.
       
   157  *
       
   158  * @since 2.0.0
       
   159  * @see wp_shrink_dimensions()
       
   160  *
       
   161  * @param int $width Current width of the image
       
   162  * @param int $height Current height of the image
       
   163  * @return mixed Array(height,width) of shrunk dimensions.
       
   164  */
       
   165 function get_udims( $width, $height) {
       
   166 	return wp_shrink_dimensions( $width, $height );
       
   167 }
       
   168 
       
   169 /**
       
   170  * Calculates the new dimentions for a downsampled image.
       
   171  *
       
   172  * @since 2.0.0
       
   173  * @see wp_constrain_dimensions()
       
   174  *
       
   175  * @param int $width Current width of the image
       
   176  * @param int $height Current height of the image
       
   177  * @param int $wmax Maximum wanted width
       
   178  * @param int $hmax Maximum wanted height
       
   179  * @return mixed Array(height,width) of shrunk dimensions.
       
   180  */
       
   181 function wp_shrink_dimensions( $width, $height, $wmax = 128, $hmax = 96 ) {
       
   182 	return wp_constrain_dimensions( $width, $height, $wmax, $hmax );
       
   183 }
       
   184 
       
   185 /**
       
   186  * Convert a fraction string to a decimal.
       
   187  *
       
   188  * @since 2.5.0
       
   189  *
       
   190  * @param string $str
       
   191  * @return int|float
       
   192  */
       
   193 function wp_exif_frac2dec($str) {
       
   194 	@list( $n, $d ) = explode( '/', $str );
       
   195 	if ( !empty($d) )
       
   196 		return $n / $d;
       
   197 	return $str;
       
   198 }
       
   199 
       
   200 /**
       
   201  * Convert the exif date format to a unix timestamp.
       
   202  *
       
   203  * @since 2.5.0
       
   204  *
       
   205  * @param string $str
       
   206  * @return int
       
   207  */
       
   208 function wp_exif_date2ts($str) {
       
   209 	@list( $date, $time ) = explode( ' ', trim($str) );
       
   210 	@list( $y, $m, $d ) = explode( ':', $date );
       
   211 
       
   212 	return strtotime( "{$y}-{$m}-{$d} {$time}" );
       
   213 }
       
   214 
       
   215 /**
       
   216  * Get extended image metadata, exif or iptc as available.
       
   217  *
       
   218  * Retrieves the EXIF metadata aperture, credit, camera, caption, copyright, iso
       
   219  * created_timestamp, focal_length, shutter_speed, and title.
       
   220  *
       
   221  * The IPTC metadata that is retrieved is APP13, credit, byline, created date
       
   222  * and time, caption, copyright, and title. Also includes FNumber, Model,
       
   223  * DateTimeDigitized, FocalLength, ISOSpeedRatings, and ExposureTime.
       
   224  *
       
   225  * @todo Try other exif libraries if available.
       
   226  * @since 2.5.0
       
   227  *
       
   228  * @param string $file
       
   229  * @return bool|array False on failure. Image metadata array on success.
       
   230  */
       
   231 function wp_read_image_metadata( $file ) {
       
   232 	if ( !file_exists( $file ) )
       
   233 		return false;
       
   234 
       
   235 	list(,,$sourceImageType) = getimagesize( $file );
       
   236 
       
   237 	// exif contains a bunch of data we'll probably never need formatted in ways
       
   238 	// that are difficult to use. We'll normalize it and just extract the fields
       
   239 	// that are likely to be useful.  Fractions and numbers are converted to
       
   240 	// floats, dates to unix timestamps, and everything else to strings.
       
   241 	$meta = array(
       
   242 		'aperture' => 0,
       
   243 		'credit' => '',
       
   244 		'camera' => '',
       
   245 		'caption' => '',
       
   246 		'created_timestamp' => 0,
       
   247 		'copyright' => '',
       
   248 		'focal_length' => 0,
       
   249 		'iso' => 0,
       
   250 		'shutter_speed' => 0,
       
   251 		'title' => '',
       
   252 	);
       
   253 
       
   254 	// read iptc first, since it might contain data not available in exif such
       
   255 	// as caption, description etc
       
   256 	if ( is_callable('iptcparse') ) {
       
   257 		getimagesize($file, $info);
       
   258 		if ( !empty($info['APP13']) ) {
       
   259 			$iptc = iptcparse($info['APP13']);
       
   260 			if ( !empty($iptc['2#110'][0]) ) // credit
       
   261 				$meta['credit'] = utf8_encode(trim($iptc['2#110'][0]));
       
   262 			elseif ( !empty($iptc['2#080'][0]) ) // byline
       
   263 				$meta['credit'] = utf8_encode(trim($iptc['2#080'][0]));
       
   264 			if ( !empty($iptc['2#055'][0]) and !empty($iptc['2#060'][0]) ) // created date and time
       
   265 				$meta['created_timestamp'] = strtotime($iptc['2#055'][0] . ' ' . $iptc['2#060'][0]);
       
   266 			if ( !empty($iptc['2#120'][0]) ) // caption
       
   267 				$meta['caption'] = utf8_encode(trim($iptc['2#120'][0]));
       
   268 			if ( !empty($iptc['2#116'][0]) ) // copyright
       
   269 				$meta['copyright'] = utf8_encode(trim($iptc['2#116'][0]));
       
   270 			if ( !empty($iptc['2#005'][0]) ) // title
       
   271 				$meta['title'] = utf8_encode(trim($iptc['2#005'][0]));
       
   272 		 }
       
   273 	}
       
   274 
       
   275 	// fetch additional info from exif if available
       
   276 	if ( is_callable('exif_read_data') && in_array($sourceImageType, apply_filters('wp_read_image_metadata_types', array(IMAGETYPE_JPEG, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM)) ) ) {
       
   277 		$exif = @exif_read_data( $file );
       
   278 		if (!empty($exif['FNumber']))
       
   279 			$meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
       
   280 		if (!empty($exif['Model']))
       
   281 			$meta['camera'] = trim( $exif['Model'] );
       
   282 		if (!empty($exif['DateTimeDigitized']))
       
   283 			$meta['created_timestamp'] = wp_exif_date2ts($exif['DateTimeDigitized']);
       
   284 		if (!empty($exif['FocalLength']))
       
   285 			$meta['focal_length'] = wp_exif_frac2dec( $exif['FocalLength'] );
       
   286 		if (!empty($exif['ISOSpeedRatings']))
       
   287 			$meta['iso'] = $exif['ISOSpeedRatings'];
       
   288 		if (!empty($exif['ExposureTime']))
       
   289 			$meta['shutter_speed'] = wp_exif_frac2dec( $exif['ExposureTime'] );
       
   290 	}
       
   291 
       
   292 	return apply_filters( 'wp_read_image_metadata', $meta, $file, $sourceImageType );
       
   293 
       
   294 }
       
   295 
       
   296 /**
       
   297  * Validate that file is an image.
       
   298  *
       
   299  * @since 2.5.0
       
   300  *
       
   301  * @param string $path File path to test if valid image.
       
   302  * @return bool True if valid image, false if not valid image.
       
   303  */
       
   304 function file_is_valid_image($path) {
       
   305 	$size = @getimagesize($path);
       
   306 	return !empty($size);
       
   307 }
       
   308 
       
   309 /**
       
   310  * Validate that file is suitable for displaying within a web page.
       
   311  *
       
   312  * @since 2.5.0
       
   313  * @uses apply_filters() Calls 'file_is_displayable_image' on $result and $path.
       
   314  *
       
   315  * @param string $path File path to test.
       
   316  * @return bool True if suitable, false if not suitable.
       
   317  */
       
   318 function file_is_displayable_image($path) {
       
   319 	$info = @getimagesize($path);
       
   320 	if ( empty($info) )
       
   321 		$result = false;
       
   322 	elseif ( !in_array($info[2], array(IMAGETYPE_GIF, IMAGETYPE_JPEG, IMAGETYPE_PNG)) )	// only gif, jpeg and png images can reliably be displayed
       
   323 		$result = false;
       
   324 	else
       
   325 		$result = true;
       
   326 
       
   327 	return apply_filters('file_is_displayable_image', $result, $path);
       
   328 }
       
   329 
       
   330 ?>