如果图像是透明背景，是否意味着每个像素的alpha都为0？

Question

I am wondering if an image is transparent background, does it mean every pixel's alpha value is 0? Or some are 0, some not?

Answer 1

100％透明像素的alpha值为0。10％不透明像素（半透明）的alpha值为10。具有透明度混合的图像具有alpha值的混合。