Test script for comparing imagine scaled file sizes.

composer.json

{
    "name": "imagine/test",
    "require": {
        "imagine/imagine": "^1.2",
        "rokka/imagine-vips": "0.12.0"
    }

test.php

<?php
require 'vendor/autoload.php';

$vips = new Imagine\Vips\Imagine();
$imagick = new Imagine\Imagick\Imagine();
$gd = new Imagine\Gd\Imagine();

$size    = new Imagine\Image\Box(700, 439);

$mode    = Imagine\Image\ImageInterface::THUMBNAIL_INSET;

$vips->open('original.png')
    ->thumbnail($size, $mode)
    ->save('thumbnail-vips-' . $size->getWidth() . 'x' . $size->getHeight() . '.png', array('png_compression_level' => 0, 'png_quality' => 90 )) 
;
$imagick->open('original.png')
    ->thumbnail($size, $mode)
    ->save('thumbnail-im-' . $size->getWidth() . 'x' . $size->getHeight() . '.png', array('png_compression_level' => 0, 'quality' => 90))
;
$gd->open('original.png')
    ->thumbnail($size, $mode)
    ->save('thumbnail-gd-' . $size->getWidth() . 'x' . $size->getHeight() . '.png', array('png_compression_level' => 0, 'quality' => 90))
;