PHP Imagick JPG compression quality 1 to 100

Comparing Imagick a PHP image plugin JPG image file compression from 1 (lowest) through to 100.

The original image was 1MB and the code used to do this test was:

<?php
foreach (range(1, 100) as $i) {
    $im = new Imagick();
    $im->readImage("ogimage.jpg");
    $im->setImageCompression(Imagick::COMPRESSION_JPEG);
    $im->setImageCompressionQuality($i);
    $im->setImageFormat("jpg");
    $im->stripImage();
    $im->writeImage("output/$i.jpg");
    $im->destroy();
    echo "$i is done<br>";
}

The compressed file sizes:

Imagick php jpg compression quality size

Quality 64 is actually when the file size starts to drop, whilst 77 through to 100 add-on size. Quality 1 through to 20 has discoloration and obvious pixels.

The original image:

Quality 64

Quality 50

Quality 30

Quality 20

Quality 1