Layer Blending Basics

The so-called "layer blending mode", as the name implies, refers to the two layers of the image on the "mixed" way to get a new mixed result graph.

The images on two layers are not "mixed" directly. Are "mixed" by their own red, green, and blue channels.

The image in 1.ps is controlled by its channel, when you edit the image, you operate on the layer, and the processing work is silently in the channel.

2.RGB-mode images (such as JPG) have red, green, and blue three channels (the CYMK mode has 4 channels).

3. Red, green, blue three channels of pixels are (gray scale value of 0-255) gray.

The following figure shows how the "blending" is done and the "blending" process. I don't know if I can say it clearly.

First, a few related concepts and knowledge:

1. Mixing mode is fastidious "grass-roots" (lower), "mixed layer" (upper). "Grassroots" is the mixed layer (layer position below), "mixed layer" is to mix "grass-roots

"Layer (layer position above). Mixed-mode algorithms in some of the upper and lower is required, and some can be switched up and down, after the upper and lower layer exchange, the mixed results unchanged.

2. Mixed-mode algorithm formula is more "deep", but also more special.

For example, in a formula (for example, a):

1. General a refers to "grass-roots (figure)", General B refers to "mixed layer (Fig)", r is the result layer (FIG).

2.A is also referred to as "grassroots" in the channel of gray-scale values. The gray-scale value of this a is different in the red, green, and blue three channels.

3. The range of a value in the channel is 0-255, and 0-255 is still discontinuous (all positive integers). The maximum value is 255. (This is not the same as the general concept of mathematics, it is a proprietary mathematical concept for digital image processing.) ）

4. In the formula, the value of the complementary color of a value is computed by: 255-a. For example, the value of a in the red channel is 125, and its complementary color value is 225-125=100.

OK, look at the diagram below!

The following picture A and B pictures put up, interested friends can be hands-on experiments to verify.

To realize the magic of PS, hands-on is the most important. Otherwise, you will always wander outside the gate!!!