(PHP 5 >= 5.5.0, PHP 7, PHP 8)
imagecrop — Crop an image to the given rectangle
   Crops an image to the given rectangular area and returns the resulting image.
   The given image is not modified.
  
image由图象创建函数(例如imagecreatetruecolor())返回的图象资源。
rectangle
      The cropping rectangle as array with keys
      x, y, width and
      height.
     
   Return cropped image object on success 或者在失败时返回 false.
  
| 版本 | 说明 | 
|---|---|
| 8.0.0 | imageexpects a GdImage
  instance now; previously, a resource was expected. | 
| 8.0.0 | On success, this function returns a GDImage instance now; previously, a resource was returned. | 
示例 #1 imagecrop() example
This example shows how to crop an image to a square area.
<?php
$im = imagecreatefrompng('example.png');
$size = min(imagesx($im), imagesy($im));
$im2 = imagecrop($im, ['x' => 0, 'y' => 0, 'width' => $size, 'height' => $size]);
if ($im2 !== FALSE) {
    imagepng($im2, 'example-cropped.png');
    imagedestroy($im2);
}
imagedestroy($im);
?>