01// 剪切图片
02function cut_img($src_image, $out_image = null, int $new_width = null, int $new_height = null, $img_quality = 90)
03{
04// 输出地址
05if (! $out_image)
06$out_image = $src_image;
07
08// 读取配置文件设置
09if (! $new_width && ! $new_height)
10return;
11
12// 获取图片属性
13list ($width, $height, $type, $attr) = getimagesize($src_image);
14switch ($type) {
15case 1:
16$img = imagecreatefromgif($src_image);
17break;
18case 2:
19$img = imagecreatefromjpeg($src_image);
20break;
21case 3:
22$img = imagecreatefrompng($src_image);
23break;
24}
25
26// 不限定是等比例缩放
27if (! $new_width) {
28$new_width = floor($width * ($new_height / $height));
29}
30if (! $new_height) {
31$new_height = floor($height * ($new_width / $width));
32}
33// 创建画布
34$new_img = imagecreatetruecolor($new_width, $new_height);
35
36// 创建透明画布,避免黑色
37if ($type == 1 || $type == 3) {
38$color = imagecolorallocate($new_img, 255, 255, 255);
39imagefill($new_img, 0, 0, $color);
40imagecolortransparent($new_img, $color);
41}
42
43
44// 先缩放
45$scale = max($new_width / $width, $new_height / $height);
46$scale_width = floor($scale * $width);
47$scale_height = floor($scale * $height);
48$scale_img = imagecreatetruecolor($scale_width, $scale_height); // 创建画布
49if(function_exists("ImageCopyResampled")) {
50imagecopyresampled($scale_img, $img, 0, 0, 0, 0, $scale_width, $scale_height, $width, $height);
51} else {
52imagecopyresized($scale_img, $img, 0, 0, 0, 0, $scale_width, $scale_height, $width, $height);
53}
54//再裁剪
55$start_x = ($scale_width - $new_width) / 2;
56$start_y = ($scale_height - $new_height) / 2;
57
58//拷贝剪切的图像数据到画板，生成剪切图像
59imagecopy($new_img, $scale_img, 0, 0, $start_x, $start_y, $scale_width, $scale_height);
60
61check_dir(dirname($out_image), true); // 检查输出目录
62
63switch ($type) {
64case 1:
65imagegif($new_img, $out_image, $img_quality);
66break;
67case 2:
68imagejpeg($new_img, $out_image, $img_quality);
69break;
70case 3:
71imagepng($new_img, $out_image, $img_quality / 10); // $quality参数取值范围0-99 在php 5.1.2之后变更为0-9
72break;
73default:
74imagejpeg($new_img, $out_image, $img_quality);
75}
76imagedestroy($new_img);
77imagedestroy($img);
78return true;
79}
