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：
<span style="font-size: 18px; ">$(function(){
$('#cropbox').Jcrop({
aspectRatio: 1,
onSelect: updateCoords
});
});</span>，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 | decimal 0 - 1 | Opacity of outer image when cropping | .6 |
<span style="font-size:18px;">function updateCoords(c)
{
$('#x').val(c.x);
$('#y').val(c.y);
$('#w').val(c.w);
$('#h').val(c.h);
};</span><span style="font-size:18px;"><form action="crop.php" method="post" onsubmit="return checkCoords();"> <input type="hidden" id="x" name="x"> <input type="hidden" id="y" name="y"> <input type="hidden" id="w" name="w"> <input type="hidden" id="h" name="h"> <input type="submit" value="Crop Image"> </form></span>
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。
<span style="font-size:18px;">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;
}
} </span>
截完图之后：
