php 图片调整大小 封装类

  1 <?php
  2 class ImageResize
  3 {
  4     private $image;
  5     private $img_des;
  6     private $image_type;
  7     private $permissions;
  8     private $compression;
  9  
 10     /**
 11      * 构造函数
 12      * @param string $img_src     源图片
 13      * @param string $img_des     保存图片对象
 14      * @param int    $compression 压缩比率，范围0-100(0:压缩比最高，100：压缩比最低)
 15      * @param null   $permissions 改变文件模式
 16      *                            mode 参数由 4 个数字组成：
 17      *                            第一个数字永远是 0
 18      *                            第二个数字规定所有者的权限
 19      *                            第二个数字规定所有者所属的用户组的权限
 20      *                            第四个数字规定其他所有人的权限
 21      *                            1 - 执行权限，2 - 写权限，4 - 读权限
 22      */
 23     function __construct($img_src, $img_des = NULL, $compression = 75, $permissions = null)
 24     {
 25         $image_info = getimagesize($img_src);
 26  
 27         $this->img_des = $img_des;
 28         $this->image_type = $image_info[2];
 29         $this->compression = $compression;
 30         $this->permissions = $permissions;
 31  
 32         if ($this->image_type == IMAGETYPE_JPEG) {
 33             $this->image = ImageCreateFromJPEG($img_src);
 34         } elseif ($this->image_type == IMAGETYPE_GIF) {
 35             $this->image = ImageCreateFromGIF($img_src);
 36         } elseif ($this->image_type == IMAGETYPE_PNG) {
 37             $this->image = ImageCreateFromPNG($img_src);
 38         }
 39     }
 40  
 41     /**
 42      * 保存图片
 43      */
 44     function save()
 45     {
 46         if ($this->image_type == IMAGETYPE_JPEG) {
 47             imagejpeg($this->image, $this->img_des, $this->compression);
 48         } elseif ($this->image_type == IMAGETYPE_GIF) {
 49             imagegif($this->image, $this->img_des);
 50         } elseif ($this->image_type == IMAGETYPE_PNG) {
 51             imagepng($this->image, $this->img_des);
 52         }
 53  
 54         if ($this->permissions != null) {
 55             chmod($this->image, $this->compression);
 56         }
 57     }
 58  
 59     /**
 60      * 做为图片流直接输出
 61      */
 62     function output()
 63     {
 64         if ($this->image_type == IMAGETYPE_JPEG) {
 65             header(‘Content-Type: image/jpg‘);
 66             imagejpeg($this->image);
 67         } elseif ($this->image_type == IMAGETYPE_GIF) {
 68             header(‘Content-Type: image/gif‘);
 69             imagegif($this->image);
 70         } elseif ($this->image_type == IMAGETYPE_PNG) {
 71             header(‘Content-Type: image/png‘);
 72             imagepng($this->image);
 73         }
 74     }
 75  
 76     /**
 77      * 获取图片宽度
 78      * @return int 图片宽度
 79      */
 80     function getWidth()
 81     {
 82         return imagesx($this->image);
 83     }
 84  
 85     /*
 86      * 获取图片高度
 87      * @return int 图片高度
 88      */
 89     function getHeight()
 90     {
 91         return imagesy($this->image);
 92     }
 93  
 94     /**
 95      * 按照固定高度缩放图片
 96      * @param $height 需要改变大小的高度
 97      */
 98     function resizeToHeight($height)
 99     {
100         $ratio = $height / $this->getHeight();
101         $width = $this->getWidth() * $ratio;
102         $this->resize($width, $height);
103     }
104  
105     /**
106      * 按照固定宽度缩放图片
107      * @param $width 指定宽度
108      */
109     function resizeToWidth($width)
110     {
111         $ratio = $width / $this->getWidth();
112         $height = $this->getheight() * $ratio;
113         $this->resize($width, $height);
114     }
115  
116     /**
117      * 等比缩放图片
118      * @param int $scale 缩放比例
119      */
120     function scale($scale)
121     {
122         $width = $this->getWidth() * $scale / 100;
123         $height = $this->getheight() * $scale / 100;
124         $this->resize($width, $height);
125     }
126  
127  
128     /**
129      * 指定宽度和高度缩放图片
130      * @param int $width  缩放宽度
131      * @param int $height 缩放高度
132      * @return 缩放后图片对象
133      */
134     function resize($width, $height)
135     {
136         $new_image = imagecreatetruecolor($width, $height);
137  
138         if ($this->image_type == IMAGETYPE_GIF || $this->image_type == IMAGETYPE_PNG) {
139             $current_transparent = imagecolortransparent($this->image);
140             if ($current_transparent != -1) {
141                 $transparent_color = imagecolorsforindex($this->image, $current_transparent);
142                 $current_transparent = imagecolorallocate($new_image, $transparent_color[‘red‘], $transparent_color[‘green‘], $transparent_color[‘blue‘]);
143                 imagefill($new_image, 0, 0, $current_transparent);
144                 imagecolortransparent($new_image, $current_transparent);
145             } elseif ($this->image_type == IMAGETYPE_PNG) {
146                 imagealphablending($new_image, false);
147                 $color = imagecolorallocatealpha($new_image, 0, 0, 0, 127);
148                 imagefill($new_image, 0, 0, $color);
149                 imagesavealpha($new_image, true);
150             }
151         }
152  
153         imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
154         $this->image = $new_image;
155     }
156 }
157  
158 ?>

1 $image = new ImageResize($tmp_image_name, NULL, 100);
2 $image->output();