wp-includes/media.php:792Retrieves the image's intermediate size (resized) path, width, and height.
$post_idint$sizestring|int[]optional'thumbnail'array|false$filestring
$widthint
$heightint
$pathstring
$urlstring
One hook fires while image_get_intermediate_size() runs, in this order:
Filters the output of image_get_intermediate_size()
function image_get_intermediate_size( $post_id, $size = 'thumbnail' ) { $imagedata = wp_get_attachment_metadata( $post_id ); if ( ! $size || ! is_array( $imagedata ) || empty( $imagedata['sizes'] ) ) { return false; } $data = array(); // Find the best match when '$size' is an array. if ( is_array( $size ) ) { $candidates = array(); if ( ! isset( $imagedata['file'] ) && isset( $imagedata['sizes']['full'] ) ) { $imagedata['height'] = $imagedata['sizes']['full']['height']; $imagedata['width'] = $imagedata['sizes']['full']['width']; } foreach ( $imagedata['sizes'] as $_size => $data ) { // If there's an exact match to an existing image size, short circuit. if ( (int) $data['width'] === (int) $size[0] && (int) $data['height'] === (int) $size[1] ) { $candidates[ $data['width'] * $data['height'] ] = $data; break; } // If it's not an exact match, consider larger sizes with the same aspect ratio. if ( $data['width'] >= $size[0] && $data['height'] >= $size[1] ) { // If '0' is passed to either size, we test ratios against the original file. if ( 0 === $size[0] || 0 === $size[1] ) { $same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $imagedata['width'], $imagedata['height'] ); } else { $same_ratio = wp_image_matches_ratio( $data['width'], $data['height'], $size[0], $size[1] ); } if ( $same_ratio ) { $candidates[ $data['width'] * $data['height'] ] = $data; } } } if ( ! empty( $candidates ) ) { // Sort the array by size if we have more than one candidate. if ( 1 < count( $candidates ) ) { ksort( $candidates ); } $data = array_shift( $candidates ); } elseif ( ! empty( $imagedata['sizes']['thumbnail'] ) && $size[0] <= $imagedata['sizes']['thumbnail']['width'] && $size[1] <= $imagedata['sizes']['thumbnail']['width'] ) { /* * When the size requested is smaller than the thumbnail dimensions, we * fall back to the thumbnail size to maintain backward compatibility with * pre-4.6 versions of WordPress. */ $data = $imagedata['sizes']['thumbnail']; } else { return false; } // Constrain the width and height attributes to the requested values. list( $data['width'], $data['height'] ) = image_constrain_size_for_editor( $data['width'], $data['height'], $size ); } elseif ( ! empty( $imagedata['sizes'][ $size ] ) ) { $data = $imagedata['sizes'][ $size ]; } // If we still don't have a match at this point, return false. if ( empty( $data ) ) { return false; } // Include the full filesystem path of the intermediate file. if ( empty( $data['path'] ) && ! empty( $data['file'] ) && ! empty( $imagedata['file'] ) ) { $file_url = wp_get_attachment_url( $post_id ); $data['path'] = path_join( dirname( $imagedata['file'] ), $data['file'] ); $data['url'] = path_join( dirname( $file_url ), $data['file'] ); }Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/media.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.