PHP GD图片处理[转换格式-水印-缩略图]

1/**
2 * 将图片转换为webp或其他格式，同时可以添加水印
3 *
4 * @author Otstar Lin
5 *
6 * @param String   $source            原图片地址
7 * @param String   $type              转换后图片格式
8 * @param String   $to                转换后图片地址 若为 null 则代表直接输出到浏览器
9 * @param Array    $thumbnail_size    缩略图尺寸
10 * @param Integer  $thum              要输出到浏览器的图片，当 $to == null 的时候生效, -1 代表使用原尺寸图，其他数字分别代表使用 $thumbnail_size 指定索引的尺寸图
11 * @param Boolean  $watermark         是否加水印
12 * @param Integer  $watermark_type    水印格式 1：文字 2：图片
13 * @param String   $watermark_content 水印内容，若为图片则是水印图片地址
14 * @param Integer  $position          水印位置
15 * @param Integer  $alpha             水印透明度
16 * @param Array    $color             水印内容颜色
17 * @param Integer  $font_size         水印文字大小
18 * @param String   $font_name         水印字体地址
19 */
20function image_change($source, $type='webp', $to = null, $thumbnail_size = [], $thum = -1,
21                      $watermark = false, $watermark_type = 1, $watermark_content = '', $position = 9,
22                      $alpha = 0, $color = [0, 0, 0], $font_size = 14, $font_name = 'Roboto-Medium.ttf')
23{
24    $image = imagecreatefromstring(file_get_contents($source));
25    // 生成水印
26    if($watermark) {
27        // 获取原图信息
28        $image_info = getimagesize($source);
29        // 设置颜色
30        $content_color = imagecolorallocatealpha($image, $color[0], $color[1], $color[2], $alpha);
31        // 载入字体
32        putenv('GDFONTPATH=' . realpath('.'));
33        $font = $font_name;
34        $left = 0;
35        $top = 0;
36        // 获取水印占据的空间大小
37        $watermark_content_info = [];
38        if($watermark_type == 1) {
39            $temp = imagettfbbox($font_size, 0, $font_name, $watermark_content);
40            $watermark_content_info[] = $temp[2] - $temp[0];
41            $watermark_content_info[] = $temp[1] - $temp[7];
42        } else {
43            $temp = getimagesize($watermark_content);
44            $watermark_content_info[] = $temp[0];
45            $watermark_content_info[] = $temp[1];
46        }
47        // 对水印进行定位
48        switch($position) {
49            case 1:
50                $left = 20;
51                $top = 20;
52                break;
53            case 2:
54                $left = $image_info[0]/2 - $watermark_content_info[0]/2;
55                $top = 20;
56                break;
57            case 3:
58                $left = $image_info[0] - $watermark_content_info[0] - 20;
59                $top = 20;
60                break;
61            case 4:
62                $left = 20;
63                $top = $image_info[1]/2 - $watermark_content_info[1]/2;
64                break;
65            case 5:
66                $left = $image_info[0]/2 - $watermark_content_info[0]/2;
67                $top = $image_info[1]/2 - $watermark_content_info[1]/2;
68                break;
69            case 6:
70                $left = $image_info[0] - $watermark_content_info[0] - 20;
71                $top = $image_info[1]/2 - $watermark_content_info[1]/2;
72                break;
73            case 7:
74                $left = 20;
75                $top = $image_info[1] - $watermark_content_info[1] - 20;
76                break;
77            case 8:
78                $left = $image_info[0]/2 - $watermark_content_info[0]/2;
79                $top = $image_info[1] - $watermark_content_info[1] - 20;
80                break;
81            case 9:
82                $left = $image_info[0] - $watermark_content_info[0] - 20;
83                $top = $image_info[1] - $watermark_content_info[1] - 20;
84                break;
85        }
86        // 对文字水印和图片水印进行不同的处理
87        if($watermark_type == 1) {
88            imagettftext($image, $font_size, 0, $left, $font_size + $top, $content_color, $font, $watermark_content);
89        } else {
90            $watermark_image = imagecreatefromstring(file_get_contents($watermark_content));
91            imagecopy($image, $watermark_image, $left, $top, 0, 0, $watermark_content_info[0], $watermark_content_info[1]);
92        }
93    }
94    // 获取图片文件名（去除后缀）
95    $image_pathinfo = pathinfo($source);
96    $image_name = str_replace('.'.$image_pathinfo['extension'], '', $image_pathinfo['basename']);
97    $path = null;
98    // 输出原图
99    if($to === null) {
100        header('Content-type:image/'.$type);
101    } else {
102        $path = $to.$image_name.'.'.$type;
103    }
104    if($type == 'jepg') {
105        if($thum == -1) imagejpeg($image, $path);
106    } else if($type == 'png') {
107        if($thum == -1) imagepng($image, $path);
108    } else {
109        if($thum == -1) imagewebp($image, $path);
110    }
111    // 输出缩略图
112    foreach ($thumbnail_size as $num => $size) {
113        $set = true;
114        if(!isset($size['height'])) {
115            $set = false;
116            $size['height'] = $size['width'] * $image_info[1]/$image_info[0];
117        }
118        $thum_img = imagecreatetruecolor($size['width'], $size['height']);
119        imagecopyresampled($thum_img, $image, 0, 0, 0, 0, $size['width'], $size['height'], $image_info[0], $image_info[1]);
120        if($to !== null) {
121            if($type == 'jepg') {
122                imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
123            } else if($type == 'png') {
124                imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
125            } else {
126                imagewebp($thum_img, $to.$image_name.'-'.$size['width'].'.'.$type);
127            }
128        } else {
129            if($num == $thum) {
130                if($type == 'jepg') {
131                    imagewebp($thum_img);
132                } else if($type == 'png') {
133                    imagewebp($thum_img);
134                } else {
135                    imagewebp($thum_img);
136                }
137            }
138        }
139    }
140}
141// 缩略图的尺寸
142$thum = [
143    [
144        'width' => 200,
145    ],
146    [
147        'width' => 400,
148        'height' => 200
149    ]
150];
151image_change('img.png', 'webp', '', $thum, -1, true, 1, 'Otstar Lin', 9, 0);