本文实例为大家分享了PHP实现等比例压缩图片的具体代码，供大家参考，具体内容如下
$new_width = $width;//压缩后的图片宽
$new_height = $height;//压缩后的图片高
if($width >= 600){
$per = 600 / $width;//计算比例
$new_width = $width * $per;
$new_height = $height * $per;
}
switch ($type) {
case 1:
$giftype = check_gifcartoon($imgsrc);
if ($giftype) {
header('Content-Type:image/gif');
$image_wp = imagecreatetruecolor($new_width,$new_height);
$image = imagecreatefromgif($imgsrc);
image<a href="https://www.jb51.cc/tag/cop/" target="_blank" class="keywords">cop</a>yresampled($image_wp,$image,$new_width,$new_height,$width,$height);
//90代表的是质量、压缩<a href="https://www.jb51.cc/tag/tupian/" target="_blank" class="keywords">图片</a>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);
image<a href="https://www.jb51.cc/tag/cop/" target="_blank" class="keywords">cop</a>yresampled($image_wp,$height);
//90代表的是质量、压缩<a href="https://www.jb51.cc/tag/tupian/" target="_blank" class="keywords">图片</a>容量大小
imagejpeg($image_wp,90);
imagedestroy($image_wp);
imagedestroy($image);
break;
case 3:
header('Content-Type:image/png');
$image_wp = imagecreatetruecolor($new_width,$new_height);
$image = <a href="https://www.jb51.cc/tag/imagecreatefrompng/" target="_blank" class="keywords">imagecreatefrompng</a>($imgsrc);
image<a href="https://www.jb51.cc/tag/cop/" target="_blank" class="keywords">cop</a>yresampled($image_wp,90);
imagedestroy($image_wp);
imagedestroy($image);
break;
}
}
