PHP Image Compression: Methods Guide

In PHP, there are several common methods for compressing images.

1. By using the GD library: The GD library is a graphics library for PHP that can achieve compression by adjusting image quality parameters. Below is an example code:

$sourceImage = imagecreatefromjpeg('source.jpg');
$destinationImage = 'compressed.jpg';
$quality = 75; // 压缩质量（0-100）
imagejpeg($sourceImage, $destinationImage, $quality);
imagedestroy($sourceImage);

1. Utilize the ImageMagick library: ImageMagick is a powerful image processing library that can achieve compression by adjusting parameters. Here is an example code:

$sourceImage = new Imagick('source.jpg');
$sourceImage->setImageCompression(Imagick::COMPRESSION_JPEG);
$sourceImage->setImageCompressionQuality(75); // 压缩质量（0-100）
$sourceImage->writeImage('compressed.jpg');
$sourceImage->destroy();

1. Using third-party libraries: In addition to GD library and ImageMagick library, you can also use some third-party libraries, such as TinyPNG API or Kraken API, which provide online image compression functionality. Here is an example code using the TinyPNG API:

require_once 'vendor/autoload.php'; // 引入TinyPNG库

// 压缩图片
\Tinify\Tinify::setKey('YOUR_API_KEY'); // 设置API密钥
\Tinify\Tinify::fromFile('source.jpg')->toFile('compressed.jpg');

These methods can assist you in achieving image compression in PHP. Please choose the appropriate method based on your needs.