PHP图片压缩方法

/**

* desription 压缩图片

* @param sting $imgsrc 图片路径

* @param string $imgdst 压缩后保存路径

*/

private function compressedImage($imgsrc, $imgdst) {

list($width, $height, $type) = getimagesize($imgsrc);

$new_width = $width>800?800:$width;//图片宽度的限制

$new_height =$height>800?ceil($height*800/$width):$height;//自适应匹配图片高度

switch ($type) {

case 1:

$giftype = $this->check_gifcartoon($imgsrc);

if ($giftype) {

header('Content-Type:image/gif');

$image_wp = imagecreatetruecolor($new_width, $new_height);

$image = imagecreatefromgif($imgsrc);

imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

//90代表的是质量、压缩图片容量大小

imagejpeg($image_wp, $imgdst, 90);

imagedestroy($image_wp);

imagedestroy($image);

}

break;

case 2:

header('Content-Type:image/jpeg');

$image_wp = imagecreatetruecolor($new_width, $new_height);

$image = imagecreatefromjpeg($imgsrc);

imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

//90代表的是质量、压缩图片容量大小

imagejpeg($image_wp, $imgdst, 90);

imagedestroy($image_wp);

imagedestroy($image);

break;

case 3:

header('Content-Type:image/png');

$image_wp = imagecreatetruecolor($new_width, $new_height);

$image = imagecreatefrompng($imgsrc);

imagecopyresampled($image_wp, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);

//90代表的是质量、压缩图片容量大小

imagejpeg($image_wp, $imgdst, 90);

imagedestroy($image_wp);

imagedestroy($image);

break;

}

}

/**

* desription 判断是否gif动画

* @param sting image_file图片路径

* @return boolean t 是 f 否

*/

private function check_gifcartoon($image_file){

$fp = fopen($image_file,'rb');

$image_head = fread($fp,1024);

fclose($fp);

return preg_match("/".chr(0x21).chr(0xff).chr(0x0b).'NETSCAPE2.0'."/",$image_head)?false:true;

}