PNG libraries for PHP

• GD (ext-gd) is bundled with PHP and available on almost every host. Good for thumbnails and simple drawing.
• Imagick binds ImageMagick: more formats, better resize quality, PNG metadata.
• Intervention Image is a Composer package with a fluent API that runs on top of GD or Imagick.

• GD GD (ext-gd) is the image extension bundled with PHP. How to read and write PNG files, keep transparency, set compression level, make thumbnails.
• Imagick Imagick is the PHP extension for ImageMagick. How to read and write PNG files, get the size without decoding, set compression level, read text chunks.
• Intervention Image Intervention Image is a PHP image library with a fluent API over GD, Imagick or libvips. How to read, resize and save PNG files, write palette PNGs.