test image processing

wp-image-tests.php

<?php
/**
 * Profile image loading and resizing.
 *
 * @wordpress-plugin
 * Plugin Name: Profile image processing
 * Description: Profile image loading and resizing by mime format.
 * Plugin URI: n/a
 * Version:     1.0.0
 * Author:      Adam Silverstein, Google
 * License:     Apache License 2.0
 * License URI: https://www.apache.org/licenses/LICENSE-2.0
 */

/**
 * Function to get timing data for image format and size manipulation.
 */
function image_tester_get_profiling_data() {
	error_log( 'starting tests at ' . date( 'Y-m-d H:i:s' ) );
	$source_image = 'images/test-image.jpg';

	// Filter image output to each format, measuring performance of image processing.
	$image_formats = array (
		'image/jpeg',
		'image/webp',
		'image/avif',
	);

	$image_sizes = array (
		array( 300, 300 ),
		array( 600, 600 ),
		array( 1200, 1200 ),
		array( 2400, 2400 ),
	);

	$profiling_data = array();
	$total_time = array();
	$image_path = plugin_dir_path( __FILE__ ) . $source_image;

	error_log( 'Processing image... ' .  $image_path );

	foreach( $image_formats as $format ) {

		// Log the format.
		error_log( 'Processing format: ' . $format );

		// Now, test converting the image to the output format.
		$editor = wp_get_image_editor( $image_path );

		// Skip with a warning if the editor is not available.
		if ( is_wp_error( $editor ) ) {
			echo $editor->get_error_message();
			continue;
		}

		$total_time[ $format ]['start'] = microtime( true );

		// For each size, record the time to resize and save an image.
		foreach( $image_sizes as $size ) {
			// Start timer.
			$start = microtime( true );

			// Resize the image.
			$editor->resize( $size[0], $size[1], false );

			// Save.
			$result = $editor->save( null, $format );

			// Stop the timer.
			$end = microtime( true );

			// Record the datapoint.
			array_push(
				$profiling_data,
				array (
					'format' => $format,
					'size'   => array (
						'width'  => $size[0],
						'height' => $size[1]
					),
					'filesize' => $result['filesize'],
					'time'     => $end - $start,
				)
			);
		}
		$total_time[ $format ]['end'] = microtime( true );
		$total_time[ $format ]['total'] = $total_time[ $format ]['end'] - $total_time[ $format ]['start'];
	}

	error_log( 'finished tests at ' . date( 'Y-m-d H:i:s' ) );

	return array(
		'profiling_data' => $profiling_data,
		'total_time'     => $total_time,
	);
}

function image_tests_run_tests() {
	$profiling_data = image_tester_get_profiling_data();

	// Log the data out.
	error_log( print_r( $profiling_data, true ) );
	error_log( json_encode( $profiling_data ) );

	error_log( '--------------------------------------');
	error_log( 'format, size, time' );
	// Loop thru the results and output csv data in the format: format, size_string, time
	foreach( $profiling_data['profiling_data'] as $result ) {
		error_log(
			sprintf(
				'%s, %sx%s, %s',
				$result['format'],
				$result['size']['width'],
				$result['size']['height'],
				$result['time']
			)
		);
	}
}

add_action( 'init', 'image_tests_run_tests' );