Construction organization design of passages

In photoshop, the channels are different in different image modes. The pixel color in the channel layer is composed of a set of brightness values ??of the primary colors. The channel can actually be understood as a mapping of the selected area.

First of all, the most fundamental difference between a channel layer and the same image layer is that the attributes of each pixel in the layer are represented by the values ??of the three primary colors of red, green and blue, while the pixels in the channel layer Color is composed of a set of brightness values ??of primary colors. To put it more simply: there are only different brightnesses of one color in the channel, which is a grayscale image. Channels can actually be understood as mapping of selected areas.

Channels were originally used to store selections and other information in an image file. The transparent GIF image that everyone is very familiar with actually contains a channel to tell the application (browser) Which parts need to be transparent and which parts need to show through.

For example, you have worked hard to outline some extremely irregular selection areas from the image. After saving, these "selections" will disappear. At this time, we can use channels to store "selections" as independent channel layers; when we need which selections, we can easily call them in from the channel. This function has been fully used in the photo coloring examples of special effects. Of course, you can save the "selection" as a different layer, but this is far less convenient than a channel, because the image is 24 bits, and the channel layer is 8 bits. Saving it as a channel will greatly save space; the most important thing is that it is more than one Layer images can only be saved in Photoshop's special format, and many standard image formats, such as TIF, TGA, etc., can contain channel information, which greatly facilitates information sharing between different applications.

In addition, another main function of the channel is to perform computational synthesis with the same image layer, thereby generating many incredible special effects. This function is mainly used in the production of special effects text. In addition, there are many more functions of the channel, which are not listed here. They will be explained in detail in the example operation.

In short, the concept of channel is broad and profound. It is impossible to explain it thoroughly in one or two sentences. It also needs to be understood carefully in actual operation.