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利用jquery Jcrop和 php实现截图功能
项目中用到了一个上传头像的功能，需要进行无刷新的图片上传，并对上传后的图片进行用户要求的截图，无刷新上传我就不说了，用的Juploader，相信大家并不陌生，重点讲一下jcron和php配置实现图片的截取的功能，好了，言归正传。首先介绍一下jcron的用法，我就不一一解释了，我们只看最经常用的到截图功能：
$(function(){ $('#cropbox').Jcrop({ aspectRatio: 1, onSelect: updateCoords }); });
，个参数详情解释如下：
| Option Name | Value Type | Description | Default |
|---|---|---|---|
| aspectRatio | decimal | Aspect ratio of w/h (e.g. 1 for square) | n/a |
| minSize | array [ w, h ] | Minimum width/height, use 0 for unbounded dimension | n/a |
| maxSize | array [ w, h ] | Maximum width/height, use 0 for unbounded dimension | n/a |
| setSelect | array[ x, y, x2, y2 ] | Set an initial selection area | n/a |
| bgColor | color value | Set color of background container | 'black' |
| bgOpacity | decimal0 - 1 | Opacity of outer image when cropping | .6 |
function updateCoords(c) { $('#x').val(c.x); $('#y').val(c.y); $('#w').val(c.w); $('#h').val(c.h); };
后台php主要是根据前台传递的坐标，对原图进行截取，支持jpg，png，和gif三种图片格式，当然，你可以扩展他，使他支持更多的图片格式。
class Img_shot { private $filename; private $ext; private $x; private $y; private $x1; private $y1; private $width = 124; private $height = 124; private $jpeg_quality = 90; /** * 构造器 * * */ public function __construct() { log_message('debug', "Img_shot Class Initialized"); } /** * 初始化截图对象 *@param filename 源文件路径全明 *@param width 截图的宽 *@param height 截图的高 *@param x 横坐标1 *@param y 纵坐标1 *@param x1 横坐标1 *@param y1 横坐标2 * */ public function initialize($filename,$x,$y,$x1,$y1) { if(file_exists($filename)) { $this->filename = $filename; $pathinfo = pathinfo($filename); $this->ext = $pathinfo['extension']; } else { $e = new Exception('the file is not exists!',1050); throw $e; } $this->x = $x; $this->y = $y; $this->x1 = $x1; $this->y1 = $y1; } /** * 生成截图 * 根据图片的格式，生成不同的截图 */ public function generate_shot() { switch($this->ext) { case 'jpg': return $this->generate_jpg(); break; case 'png': return $this->generate_png(); break; case 'gif': return $this->generate_gif(); break; default: return false; } } /** * 得到生成的截图的文件名 * */ private function get_shot_name() { $pathinfo = pathinfo($this->filename); $fileinfo = explode('.',$pathinfo['basename']); $filename = $fileinfo[0] . '_small.' . $this->ext; return $pathinfo['dirname'] . '/' .$filename; } /** * 生成jpg格式的图片 * */ private function generate_jpg() { $shot_name = $this->get_shot_name(); $img_r = imagecreatefromjpeg($this->filename); $dst_r = ImageCreateTrueColor($this->width, $this->height); imagecopyresampled($dst_r,$img_r,0,0,$this->x,$this->y, $this->width,$this->height,$this->x1,$this->y1); imagejpeg($dst_r,$shot_name,$this->jpeg_quality); return $shot_name; } /** * 生成gif格式的图片 * */ private function generate_gif() { $shot_name = $this->get_shot_name(); $img_r = imagecreatefromgif($this->filename); $dst_r = ImageCreateTrueColor($this->width, $this->height); imagecopyresampled($dst_r,$img_r,0,0,$this->x,$this->y, $this->width,$this->height,$this->x1,$this->y1); imagegif($dst_r,$shot_name); return $shot_name; } /** * 生成png格式的图片 * */ private function generate_png() { $shot_name = $this->get_shot_name(); $img_r = imagecreatefrompng($this->filename); $dst_r = ImageCreateTrueColor($this->width, $this->height); imagecopyresampled($dst_r,$img_r,0,0,$this->x,$this->y, $this->width,$this->height,$this->x1,$this->y1); imagepng($dst_r,$shot_name); return $shot_name; } }
截完图之后：