image - 颜色键在图像处理中的作用是什么？

Question

我在一些图像处理软件中看到，我们可以指定“色键颜色”，通常是255,0, 255 in RGB。这是什么意思？

Answer 1

color key color表示“不可见”的颜色。或者，换句话说，透明 channel ，如 Alpha channel 。与色度键直接相关http://en.wikipedia.org/wiki/Chroma_key
另请阅读这篇 http://www.saltw.net/index.php?topic=82117.0部分文本名为 Using Color Keying on 2D Sprites

What does this mean to you in this stage of computing? If you look back at the last image of where we left off you would see there are big white boxes that don't blend to the background. What we want from the sprite is just the plane or the helishark. This problem existed back then so one color in that 256 color pallete was called a Color Key. This key when read by the computer would be understood to 'don't draw this pixel, it is invisible.' It's still used today as it is a very simple concept: If a pixel is this color, don't draw it!