php image compression || php image optimization

2016/03/02

http://www.mikkonen.info/imageutil/

=====2015/11/29

http://www.smashingmagazine.com/2015/06/efficient-image-resizing-with-imagemagick/

From my tests, running ImageMagick with the following settingsproduced the smallest results, while generally being visually indistinguishable from Photoshop’s output:

mogrify -path OUTPUT_PATH -filter Triangle -define filter:support=2 -thumbnail OUTPUT_WIDTH -unsharp 0.25x0.25+8+0.065 -dither None -posterize 136 -quality 82 -define jpeg:fancy-upsampling=off -define png:compression-filter=5 -define png:compression-level=9 -define png:compression-strategy=1 -define png:exclude-chunk=all -interlace none -colorspace sRGB -strip INPUT_PATH

I looked at 11 different functions and found that -thumbnail does the best job of optimizing quality and file size.

PHP

composer require nwtn/php-respimg

require_once(‘vendor/autoload.php’);
use nwtn\Respimg as Respimg;
$image = new Respimg($input_filename);
$image->smartResize($output_width, 0, false);
$image->writeImage($output_filename);

At the moment the script is a bit limited, and there’s no *great* way to do this. However, you could try running it in a loop on the command line, like this: