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 ?>

使用方法：

1 $image = new ImageResize($tmp_image_name, NULL, 100);

2 $image->output();