php 图片调整大小 封装类【转载】

              1 <?php
  2class ImageResize
  3{
  4private$image;
  5private$img_des;
  6private$image_type;
  7private$permissions;
  8private$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   $permissions 改变文件模式
 16     *                            mode 参数由 4 个数字组成：
 17     *                            第一个数字永远是 0
 18     *                            第二个数字规定所有者的权限
 19     *                            第二个数字规定所有者所属的用户组的权限
 20     *                            第四个数字规定其他所有人的权限
 21     *                            1 - 执行权限，2 - 写权限，4 - 读权限
 22*/ 23function __construct($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 = $permissions;
 31 32if ($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*/ 44function save()
 45    {
 46if ($this->image_type == IMAGETYPE_JPEG) {
 47             imagejpeg($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, $this->img_des);
 52        }
 53 54if ($this->permissions != null) {
 55chmod($this->image, $this->compression);
 56        }
 57    }
 58 59/**
 60     * 做为图片流直接输出
 61*/ 62function output()
 63    {
 64if ($this->image_type == IMAGETYPE_JPEG) {
 65header(‘Content-Type: image/jpg‘);
 66             imagejpeg($this->image);
 67         } elseif ($this->image_type == IMAGETYPE_GIF) {
 68header(‘Content-Type: image/gif‘);
 69             imagegif($this->image);
 70         } elseif ($this->image_type == IMAGETYPE_PNG) {
 71header(‘Content-Type: image/png‘);
 72             imagepng($this->image);
 73        }
 74    }
 75 76/**
 77     * 获取图片宽度
 78     * @return int 图片宽度
 79*/ 80function getWidth()
 81    {
 82return imagesx($this->image);
 83    }
 84 85/* 86     * 获取图片高度
 87     * @return int 图片高度
 88*/ 89function getHeight()
 90    {
 91return imagesy($this->image);
 92    }
 93 94/**
 95     * 按照固定高度缩放图片
 96     * @param $height 需要改变大小的高度
 97*/ 98function resizeToHeight($height)
 99    {
100$ratio = $height / $this->getHeight();
101$width = $this->getWidth() * $ratio;
102$this->resize($width, $height);
103    }
104105/**
106     * 按照固定宽度缩放图片
107     * @param $width 指定宽度
108*/109function resizeToWidth($width)
110    {
111$ratio = $width / $this->getWidth();
112$height = $this->getheight() * $ratio;
113$this->resize($width, $height);
114    }
115116/**
117     * 等比缩放图片
118     * @param int $scale 缩放比例
119*/120function scale($scale)
121    {
122$width = $this->getWidth() * $scale / 100;
123$height = $this->getheight() * $scale / 100;
124$this->resize($width, $height);
125    }
126127128/**
129     * 指定宽度和高度缩放图片
130     * @param int $width  缩放宽度
131     * @param int $height 缩放高度
132     * @return 缩放后图片对象
133*/134function resize($width, $height)
135    {
136$new_image = imagecreatetruecolor($width, $height);
137138if ($this->image_type == IMAGETYPE_GIF || $this->image_type == IMAGETYPE_PNG) {
139$current_transparent = imagecolortransparent($this->image);
140if ($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        }
152153         imagecopyresampled($new_image, $this->image, 0, 0, 0, 0, $width, $height, $this->getWidth(), $this->getHeight());
154$this->image = $new_image;
155    }
156}
157158 ?>

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