Photoshop Channel application: Eliminating the Matthew effect in color

A few days ago, see the darkroom version of a friend asked a puzzled a lot of people's question: is how to effectively solve in the increase in color saturation is very easy to appear color overflow problem?

This is a problem that we often encounter, especially on the basis of color and channel poor friends, is not easy to solve, the mask has a certain foundation of friends, will naturally think of a mask to solve this problem, such as copying a copy, increase the saturation after the use of masks to erase the overflow of color.

Can think of the use of the idea of the mask is certainly correct, but the direct use of the Mask method is not ideal, if we can not need to increase the color of the area to protect the original color will not overflow, you can achieve a more understanding of the purpose.

But how are we going to find this protected area? Its gradient line is set there best, the problem is not simple, so we need to turn to the core of the channel.

Figure 1

In RGB color mode, the saturation increase to 40, the result is the original color appropriate place serious overflow, and want to increase the color of the place and not how much effect. The rich are richer, the poor are poorer, and this is the famous "Matthew Effect".

Figure 2

We convert RGB color mode to Lab color mode How about a try? The results are not ideal, and the spill seems to be more serious.

Figure 3

If you know the color mode of a friend, CMYK is based on the color mode of printing inks, it is more dim than the RGB model, perhaps with it to increase the saturation more appropriate, then we change to CMYK this color mode to see how the situation?

Seems to be better? But still the color overflow is obvious, and the place that wants to increase does not understand.

Must know another point is that the RGB color mode to the CMYK color mode, will lose a lot of color transition level, such as RGB is 16.67 million colors, go to CMYK after only thousands of kinds of color, so under normal circumstances this does not outweigh the gains.

Figure 4

The situation seems to be at the end of the rope, so we often see some later in the color overflow phenomenon, but the degree of severity just, is there really no way?

Here again we turn to the fundamental core of the channel. We will find that a channel and B channel are all based on 50% grayscale. It can reflect the gray difference of different colors.

Figure 5

2 Back to top

1, added a ALHPA1 channel:

(1) Click "Create New Channel" (Red circle)

(2) then open "Edit/Fill", select "50% grayscale", and then "OK."

For the passage of beginners, the future process to understand that there must be difficulties, this is due to the basic knowledge, but it is recommended to master the method and learn the practical application. It is also one of the learning methods to fill the foundation.

"Little common sense" what is called alpha channel?

The alpha channel is similar to other channels, displaying 256 grayscale images, varying shades of gray from black to white. Unlike a color channel, the alpha channel does not contain information that directly affects the appearance of the image, that is, it does not represent a hue or color, but a graphical representation of the mask. The black area in the alpha channel represents the opacity of the area, and the gray area represents semitransparent.

In earlier versions of Photoshop without layer functionality, the alpha channel has a very important role to play in creating projections, glow effects, bevel, emboss, and other image effects, and these technologies are still proficient in Photoshop, especially in complex constituencies, selection of details, application of images, It is essential to calculate commands, edit selections, load selections, merge selections, and so on, for advanced applications. With the help of alpha channels, you can create some incredible image effects.

Figure 6

2, now open "image/Calculation", in the dialog box, note A channel and alpha 1, blending mode is "difference." The difference pattern is often used to compare different channels and find out their differences. Especially suitable for finding neutral ash, it is based on subtracting the blend color from the base color, or, conversely, reversing the base color.

Figure 7

Classification:

• PS Getting Started Tutorial