root/tags/1.3/wp-admin/includes/image.php

<?php

function get_udims( $width, $height) {
    if ( $height <= 96 && $width <= 128 )
        return array( $width, $height);
    elseif ( $width / $height > 4 / 3 )
        return array( 128, (int) ($height / $width * 128 ));
    else
        return array( (int) ($width / $height * 96 ), 96 );
}

function wp_create_thumbnail( $file, $max_side, $effect = '' ) {

        // 1 = GIF, 2 = JPEG, 3 = PNG

    if ( file_exists( $file ) ) {
        $type = getimagesize( $file );

        // if the associated function doesn't exist - then it's not
        // handle. duh. i hope.

        if (!function_exists( 'imagegif' ) && $type[2] == 1 ) {
            $error = __( 'Filetype not supported. Thumbnail not created.' );
        }
        elseif (!function_exists( 'imagejpeg' ) && $type[2] == 2 ) {
            $error = __( 'Filetype not supported. Thumbnail not created.' );
        }
        elseif (!function_exists( 'imagepng' ) && $type[2] == 3 ) {
            $error = __( 'Filetype not supported. Thumbnail not created.' );
        } else {

            // create the initial copy from the original file
            if ( $type[2] == 1 ) {
                $image = imagecreatefromgif( $file );
            }
            elseif ( $type[2] == 2 ) {
                $image = imagecreatefromjpeg( $file );
            }
            elseif ( $type[2] == 3 ) {
                $image = imagecreatefrompng( $file );
            }

            if ( function_exists( 'imageantialias' ))
                imageantialias( $image, TRUE );

            $image_attr = getimagesize( $file );

            // figure out the longest side

            if ( $image_attr[0] > $image_attr[1] ) {
                $image_width = $image_attr[0];
                $image_height = $image_attr[1];
                $image_new_width = $max_side;

                $image_ratio = $image_width / $image_new_width;
                $image_new_height = $image_height / $image_ratio;
                //width is > height
            } else {
                $image_width = $image_attr[0];
                $image_height = $image_attr[1];
                $image_new_height = $max_side;

                $image_ratio = $image_height / $image_new_height;
                $image_new_width = $image_width / $image_ratio;
                //height > width
            }

            $thumbnail = imagecreatetruecolor( $image_new_width, $image_new_height);
            @ imagecopyresampled( $thumbnail, $image, 0, 0, 0, 0, $image_new_width, $image_new_height, $image_attr[0], $image_attr[1] );

            // 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 );

            // move the thumbnail to its final destination
            if ( $type[2] == 1 ) {
                if (!imagegif( $thumbnail, $thumbpath ) ) {
                    $error = __( "Thumbnail path invalid" );
                }
            }
            elseif ( $type[2] == 2 ) {
                if (!imagejpeg( $thumbnail, $thumbpath ) ) {
                    $error = __( "Thumbnail path invalid" );
                }
            }
            elseif ( $type[2] == 3 ) {
                if (!imagepng( $thumbnail, $thumbpath ) ) {
                    $error = __( "Thumbnail path invalid" );
                }
            }

        }
    } else {
        $error = __( 'File not found' );
    }

    if (!empty ( $error ) ) {
        return $error;
    } else {
        return apply_filters( 'wp_create_thumbnail', $thumbpath );
    }
}

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 );

    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;
}

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, $uheight) = get_udims($metadata['width'], $metadata['height']);
        $metadata['hwstring_small'] = "height='$uheight' width='$uwidth'";
        $metadata['file'] = $file;

        $max = apply_filters( 'wp_thumbnail_creation_size_limit', 3 * 1024 * 1024, $attachment_id, $file );

        if ( $max < 0 || $metadata['width'] * $metadata['height'] < $max ) {
            $max_side = apply_filters( 'wp_thumbnail_max_side_length', 128, $attachment_id, $file );
            $thumb = wp_create_thumbnail( $file, $max_side );

            if ( @file_exists($thumb) )
                $metadata['thumb'] = basename($thumb);
        }
    }
    return apply_filters( 'wp_generate_attachment_metadata', $metadata );
}

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.');

    $contents = file_get_contents( $file );

    $image = imagecreatefromstring( $contents );

    if ( !is_resource( $image ) )
        return sprintf(__("File '%s' is not an image."), $file);

    return $image;
}

function wp_shrink_dimensions( $width, $height, $wmax = 128, $hmax = 96 ) {
    if ( $height <= $hmax && $width <= $wmax )
        return array( $width, $height);
    elseif ( $width / $height > $wmax / $hmax )
        return array( $wmax, (int) ($height / $width * $wmax ));
    else
        return array( (int) ($width / $height * $hmax ), $hmax );
}

?>