WordPress/wp-admin/includes/image.php

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<?php
/**
* File contains all the administration image manipulation functions.
*
* @package WordPress
*/
/**
* wp_create_thumbnail() - Create a thumbnail from an Image given a maximum side size.
*
* @package WordPress
* @param mixed $file Filename of the original image, Or attachment id
* @param int $max_side Maximum length of a single side for the thumbnail
* @return string Thumbnail path on success, Error string on failure
*
* This function can handle most image file formats which PHP supports.
* If PHP does not have the functionality to save in a file of the same format, the thumbnail will be created as a jpeg.
*/
function wp_create_thumbnail( $file, $max_side, $deprecated = '' ) {
if ( ctype_digit( $file ) ) // Handle int as attachment ID
$file = get_attached_file( $file );
$image = wp_load_image( $file );
if ( !is_resource( $image ) )
return $image;
list($sourceImageWidth, $sourceImageHeight, $sourceImageType) = getimagesize( $file );
if ( function_exists( 'imageantialias' ))
imageantialias( $image, true );
list($image_new_width, $image_new_height) = wp_shrink_dimensions( $sourceImageWidth, $sourceImageHeight, $max_side, $max_side);
$thumbnail = imagecreatetruecolor( $image_new_width, $image_new_height);
// preserve PNG transparency
if ( IMAGETYPE_PNG == $sourceImageType && function_exists( 'imagealphablending' ) && function_exists( 'imagesavealpha' ) ) {
imagealphablending( $thumbnail, false);
imagesavealpha( $thumbnail, true);
}
imagecopyresampled( $thumbnail, $image, 0, 0, 0, 0, $image_new_width, $image_new_height, $sourceImageWidth, $sourceImageHeight );
imagedestroy( $image ); // Free up memory
// If no filters change the filename, we'll do a default transformation.
if ( basename( $file ) == $thumb = apply_filters( 'thumbnail_filename', basename( $file ) ) )
$thumb = preg_replace( '!(\.[^.]+)?$!', '.thumbnail$1', basename( $file ), 1 );
$thumbpath = str_replace( basename( $file ), $thumb, $file );
switch( $sourceImageType ){
default: // We'll create a Jpeg if we cant use its native file format
$thumb = preg_replace( '/\\.[^\\.]+$/', '.jpg', $thumb ); //Change file extension to Jpg
case IMAGETYPE_JPEG:
if (!imagejpeg( $thumbnail, $thumbpath ) )
return __( 'Thumbnail path invalid' );
break;
case IMAGETYPE_GIF:
if (!imagegif( $thumbnail, $thumbpath ) )
return __( 'Thumbnail path invalid' );
break;
case IMAGETYPE_PNG:
if (!imagepng( $thumbnail, $thumbpath ) )
return __( 'Thumbnail path invalid' );
break;
}
imagedestroy( $thumbnail ); // Free up memory
// Set correct file permissions
$stat = stat( dirname( $thumbpath ));
$perms = $stat['mode'] & 0000666; //same permissions as parent folder, strip off the executable bits
@ chmod( $thumbpath, $perms );
return apply_filters( 'wp_create_thumbnail', $thumbpath );
}
/**
* wp_crop_image() - Crop an Image to a given size.
*
* @package WordPress
* @internal Missing Long Description
* @param int $src_file The source file
* @param int $src_x The start x position to crop from
* @param int $src_y The start y position to crop from
* @param int $src_w The width to crop
* @param int $src_h The height to crop
* @param int $dst_w The destination width
* @param int $dst_h The destination height
* @param int $src_abs If the source crop points are absolute
* @param int $dst_file The destination file to write to
* @return string New filepath on success, String error message on failure
*
*/
function wp_crop_image( $src_file, $src_x, $src_y, $src_w, $src_h, $dst_w, $dst_h, $src_abs = false, $dst_file = false ) {
if ( ctype_digit( $src_file ) ) // Handle int as attachment ID
$src_file = get_attached_file( $src_file );
$src = wp_load_image( $src_file );
if ( !is_resource( $src ))
return $src;
$dst = imagecreatetruecolor( $dst_w, $dst_h );
if ( $src_abs ) {
$src_w -= $src_x;
$src_h -= $src_y;
}
if (function_exists('imageantialias'))
imageantialias( $dst, true );
imagecopyresampled( $dst, $src, 0, 0, $src_x, $src_y, $dst_w, $dst_h, $src_w, $src_h );
imagedestroy( $src ); // Free up memory
if ( ! $dst_file )
$dst_file = str_replace( basename( $src_file ), 'cropped-' . basename( $src_file ), $src_file );
$dst_file = preg_replace( '/\\.[^\\.]+$/', '.jpg', $dst_file );
if ( imagejpeg( $dst, $dst_file ) )
return $dst_file;
else
return false;
}
/**
* wp_generate_attachment_metadata() - Generate post Image attachment Metadata
*
* @package WordPress
* @internal Missing Long Description
* @param int $attachment_id Attachment Id to process
* @param string $file Filepath of the Attached image
* @return mixed Metadata for attachment
*
*/
function wp_generate_attachment_metadata( $attachment_id, $file ) {
$attachment = get_post( $attachment_id );
$metadata = array();
if ( preg_match('!^image/!', get_post_mime_type( $attachment )) ) {
$imagesize = getimagesize( $file );
$metadata['width'] = $imagesize[0];
$metadata['height'] = $imagesize[1];
list($uwidth, $uheight) = wp_shrink_dimensions($metadata['width'], $metadata['height']);
$metadata['hwstring_small'] = "height='$uheight' width='$uwidth'";
$metadata['file'] = $file;
$max = apply_filters( 'wp_thumbnail_creation_size_limit', absint( WP_MEMORY_LIMIT ) * 1024 * 1024, $attachment_id, $file );
if ( $max < 0 || $metadata['width'] * $metadata['height'] < $max ) {
$max_side = apply_filters( 'wp_thumbnail_max_side_length', 140, $attachment_id, $file );
$thumb = wp_create_thumbnail( $file, $max_side );
if ( @file_exists($thumb) )
$metadata['thumb'] = basename($thumb);
}
// fetch additional metadata from exif/iptc
$image_meta = wp_read_image_metadata( $file );
if ($image_meta)
$metadata['image_meta'] = $image_meta;
}
return apply_filters( 'wp_generate_attachment_metadata', $metadata );
}
/**
* wp_load_image() - Load an image which PHP Supports.
*
* @package WordPress
* @internal Missing Long Description
* @param string $file Filename of the image to load
* @return resource The resulting image resource on success, Error string on failure.
*
*/
function wp_load_image( $file ) {
if ( ctype_digit( $file ) )
$file = get_attached_file( $file );
if ( ! file_exists( $file ) )
return sprintf(__("File '%s' doesn't exist?"), $file);
if ( ! function_exists('imagecreatefromstring') )
return __('The GD image library is not installed.');
// Set artificially high because GD uses uncompressed images in memory
@ini_set('memory_limit', '256M');
$image = imagecreatefromstring( file_get_contents( $file ) );
if ( !is_resource( $image ) )
return sprintf(__("File '%s' is not an image."), $file);
return $image;
}
/**
* get_udims() - Calculated the new dimentions for downsampled images
*
* @package WordPress
* @internal Missing Description
* @see wp_shrink_dimensions()
* @param int $width Current width of the image
* @param int $height Current height of the image
* @return mixed Array(height,width) of shrunk dimensions.
*
*/
function get_udims( $width, $height) {
return wp_shrink_dimensions( $width, $height );
}
/**
* wp_shrink_dimensions() - Calculates the new dimentions for a downsampled image.
*
* @package WordPress
* @internal Missing Long Description
* @param int $width Current width of the image
* @param int $height Current height of the image
* @param int $wmax Maximum wanted width
* @param int $hmax Maximum wanted height
* @return mixed Array(height,width) of shrunk dimensions.
*
*/
function wp_shrink_dimensions( $width, $height, $wmax = 128, $hmax = 96 ) {
if ( $height <= $hmax && $width <= $wmax ){
//Image is smaller than max
return array( $width, $height);
} elseif ( $width / $height > $wmax / $hmax ) {
//Image Width will be greatest
return array( $wmax, (int) ($height / $width * $wmax ));
} else {
//Image Height will be greatest
return array( (int) ($width / $height * $hmax ), $hmax );
}
}
// convert a fraction string to a decimal
function wp_exif_frac2dec($str) {
@list( $n, $d ) = explode( '/', $str );
if ( !empty($d) )
return $n / $d;
return $str;
}
// convert the exif date format to a unix timestamp
function wp_exif_date2ts($str) {
// seriously, who formats a date like 'YYYY:MM:DD hh:mm:ss'?
@list( $date, $time ) = explode( ' ', trim($str) );
@list( $y, $m, $d ) = explode( ':', $date );
return strtotime( "{$y}-{$m}-{$d} {$time}" );
}
// get extended image metadata, exif or iptc as available
function wp_read_image_metadata( $file ) {
if ( !file_exists( $file ) )
return false;
list(,,$sourceImageType) = getimagesize( $file );
// exif contains a bunch of data we'll probably never need formatted in ways that are difficult to use.
// We'll normalize it and just extract the fields that are likely to be useful. Fractions and numbers
// are converted to floats, dates to unix timestamps, and everything else to strings.
$meta = array(
'aperture' => 0,
'credit' => '',
'camera' => '',
'caption' => '',
'created_timestamp' => 0,
'copyright' => '',
'focal_length' => 0,
'iso' => 0,
'shutter_speed' => 0,
'title' => '',
);
// read iptc first, since it might contain data not available in exif such as caption, description etc
if ( is_callable('iptcparse') ) {
getimagesize($file, $info);
if ( !empty($info['APP13']) ) {
$iptc = iptcparse($info['APP13']);
if ( !empty($iptc['2#110'][0]) ) // credit
$meta['credit'] = trim( $iptc['2#110'][0] );
elseif ( !empty($iptc['2#080'][0]) ) // byline
$meta['credit'] = trim( $iptc['2#080'][0] );
if ( !empty($iptc['2#055'][0]) and !empty($iptc['2#060'][0]) ) // created datee and time
$meta['created_timestamp'] = strtotime($iptc['2#055'][0] . ' ' . $iptc['2#060'][0]);
if ( !empty($iptc['2#120'][0]) ) // caption
$meta['caption'] = trim( $iptc['2#120'][0] );
if ( !empty($iptc['2#116'][0]) ) // copyright
$meta['copyright'] = trim( $iptc['2#116'][0] );
if ( !empty($iptc['2#005'][0]) ) // title
$meta['title'] = trim( $iptc['2#005'][0] );
}
}
// fetch additional info from exif if available
if ( is_callable('exif_read_data') && in_array($sourceImageType, apply_filters('wp_read_image_metadata_types', array(IMAGETYPE_JPEG, IMAGETYPE_TIFF_II, IMAGETYPE_TIFF_MM)) ) ) {
$exif = exif_read_data( $file );
if (!empty($exif['FNumber']))
$meta['aperture'] = round( wp_exif_frac2dec( $exif['FNumber'] ), 2 );
if (!empty($exif['Model']))
$meta['camera'] = trim( $exif['Model'] );
if (!empty($exif['DateTimeDigitized']))
$meta['created_timestamp'] = wp_exif_date2ts($exif['DateTimeDigitized']);
if (!empty($exif['FocalLength']))
$meta['focal_length'] = wp_exif_frac2dec( $exif['FocalLength'] );
if (!empty($exif['ISOSpeedRatings']))
$meta['iso'] = $exif['ISOSpeedRatings'];
if (!empty($exif['ExposureTime']))
$meta['shutter_speed'] = wp_exif_frac2dec( $exif['ExposureTime'] );
}
// FIXME: try other exif libraries if available
return apply_filters( 'wp_read_image_metadata', $meta, $file, $sourceImageType );
}
?>