Index color
Some older computer-related hardware and file formats can only handle 8-bit pixels. The color range that three color frequencies can exhibit on an 8-bit display device is too small, so an 8-bit display device usually uses an index color to represent color. When you use the index color, the display system or image file is usually accompanied by a 256-color color list or palette. The system recognizes which colors are used based on the 8-bit value of each pixel. The index color will allow 8-bit display devices and images themselves to simulate full color, because the color depth of the bit palette is 24 bits.
Palette
Using an indexed color image file is accompanied by a color wheel that displays the colors of all images, and an 8-bit hardware display device is also accompanied by a color wheel that displays all supported colors for comparison. Usually when the system performs work in the indexed state, each application in the system is accompanied by a dedicated color wheel. So when we open, convert or close any of these programs, the colors on the screen will change temporarily.
Dithering and anti-aliasing
In fact, the applications that we use to draw or browse images are often unable to perform as much as possible due to insufficient hardware. For example, when the color of the image is too rich or too detailed to render the color pixels in the image impossible to represent, the real device cannot complete the entire image. This time you must use dithering and antialiasing.
Dithering
256-color monitors and image files can simulate more than 256 colors by dithering. It can use this way to spread the various patterns made up of pixels, close to the color you want.
Dithering is often used on operating systems and browsing applications, such as when using a browser on 8-bit monitors. In addition, the image editor also converts full-color images into indexed colors using dithering. However, because the use of dithering in certain conditions will make the image look worse, most image editors have listed this feature as an option. Have? Another color representation of dithering is color substitution. The way it uses is to take the closest color in the color wheel instead of the original color that should be used.
Full color image
Dithered image
Color replaced image
Anti-aliasing
If color depth considerations were to be excluded, all computers would represent pixels in a small square shape. But this method is not suitable for all images - at least for "non-" images there is a problem. If we divide the pixels very rigorously, so-called aliasing occurs. Therefore, some image processing software will use the anti-aliasing function to smooth the image. Anti-aliasing creates a smooth, non-horizontal and non-vertical dividing line to complement the gap between color and color.
Jagged image
Anti-jaggies image
If we compare the appearance of an image before and after anti-aliasing, we can clearly see that the image after “anti-jaggies†will have a smoother and clearer effect. The anti-aliased image looks not only professional but the edges of the image also appear to be less jagged. In general, this option in the image editor is highly reproducible and is used in almost all image processing. However, when using it, it is necessary to remind you that the image to use anti-aliasing must have enough color to be enough to balance the scope of the need for repair.