imagesavealpha

(PHP 4 >= 4.3.2, PHP 5, PHP 7)

imagesavealpha — 锟斤拷锟矫憋拷锟斤拷锟斤拷诒锟斤拷锟� PNG 图锟斤拷时锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷 alpha 通锟斤拷锟斤拷息锟斤拷锟诫单一透锟斤拷色锟洁反锟斤拷

说锟斤拷

imagesavealpha ( resource $image , bool $saveflag ) : bool

imagesavealpha() 锟斤拷锟矫憋拷锟斤拷锟斤拷诒锟斤拷锟� PNG 图锟斤拷时锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷 alpha 通锟斤拷锟斤拷息锟斤拷锟诫单一透锟斤拷色锟洁反锟斤拷锟斤拷

要使锟矫憋拷锟斤拷锟斤拷锟斤拷锟斤拷锟诫将 alphablending 锟斤拷位锟斤拷imagealphablending($im, false)锟斤拷锟斤拷

锟斤拷锟斤拷锟斤拷锟叫碉拷锟斤拷锟斤拷锟斤拷锟街э拷锟� alpha 通锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷猓拷锟斤拷锟斤拷眉锟斤拷锟� alpha 通锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷锟斤拷掳锟斤拷 Mozilla锟斤拷锟斤拷锟铰硷拷锟截脚憋拷锟斤拷

锟斤拷锟斤拷

image

锟斤拷图锟襟创斤拷锟斤拷锟斤拷(锟斤拷锟斤拷imagecreatetruecolor())锟斤拷锟截碉拷图锟斤拷锟斤拷源锟斤拷

saveflag

锟角否保达拷透锟斤拷锟斤拷alpha锟斤拷通锟斤拷锟斤拷 默锟斤拷 FALSE锟斤拷

锟斤拷锟斤拷值

锟缴癸拷时锟斤拷锟斤拷 TRUE锟斤拷 锟斤拷锟斤拷锟斤拷失锟斤拷时锟斤拷锟斤拷 FALSE锟斤拷

锟斤拷锟斤拷

Example #1 imagesavealpha() 锟斤拷锟斤拷

<?php
// 锟斤拷锟斤拷锟� alpha 通锟斤拷锟斤拷 png 图锟斤拷
$png = imagecreatefrompng('./alphachannel_example.png');

// 锟斤拷些锟斤拷锟斤拷牟锟斤拷锟�

// 锟截憋拷 alpha 锟斤拷染锟斤拷锟斤拷锟斤拷 alpha 锟斤拷志
imagealphablending($png, false);
imagesavealpha($png, true);

// 锟斤拷锟酵硷拷锟斤拷锟斤拷锟斤拷
header('Content-Type: image/png');

imagepng($png);
imagedestroy($png);
?>

注锟斤拷

Note: 锟剿猴拷锟斤拷锟斤拷要 GD 2.0.1 锟斤拷锟斤拷甙姹�(锟狡硷拷 2.0.28 锟斤拷锟斤拷锟竭版本)锟斤拷

锟轿硷拷