浅谈关于PHP解决图片无损压缩的问题

header("Content-type: image/jpeg");
$file = "111.jpg";
$percent = 1.5; //图片压缩比
list($width, $height) = getimagesize($file); //获取原图尺寸
/【一个开发人员，能懂服务器量好，反之一个服务器维护人员，也应该懂开发】///缩放尺寸
$newwidth = $width * $percent;
$newheight = $height * $percent;
$src_im = imagecreatefromjpeg($file);
$dst_im = imagecreatetruecolor($newwidth, $newheight);
imagecopyresized($dst_im, $src_im, 0, 0, 0, 0, $newwidth, $newheight, $width, $height);
imagejpeg($dst_im); //输出压缩后的图片
imagedestroy($dst_im);
imagedestroy($src_im);

<?php
/**
desription 压缩图片
@param sting $imgsrc 图片路径
@param string $imgdst 压缩后保存路径
*/
function image_png_size_add($imgsrc,$imgdst/【php教程_linux常用命令_网络运维技术】/){
list($width,$height,$type)=getimagesize($imgsrc);
$new_width = ($width>600?600:$width)*0.9;
$new_height =($height>600?600:$height)*0.9;
switch($type){
case 1:
$giftype=check_gifcartoon($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, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
}
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, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
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, $height);
imagejpeg($image_wp, $imgdst,75);
imagedestroy($image_wp);
break;
}
}
/**
desription 判断是否gif动画
@param sting $image_file图片路径
@return boolean t 是 f 否
*/
function check_gifcartoon($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;
}
?>