JAVA：getRGB（）从透明像素返回什么值？

Question

If i were to int RGB = image.getRGB(x,y) , where x and y were the coordinates of a transparent pixel of image , what would the value of RGB be? Null?

Answer 1

It can be basically anything. The alpha component does not correlate with the RGB component.

So for example if you have an ARGB object with (0, 45, 34, 23) and one with (0, 56, 78, 89) then they are both transparent so you don't have to care about color.

But if they are (10, 45, 34, 23), (10, 56, 78, 89) then the difference is visible. Alpha( A ) tells how opaque/transparent is something. The rest ( RGB ) tells the color of it.

Answer 2

假设您正在使用Alpha RGB BufferedImage处理图像，则应使用getAlpha（） 。