This article is a summary of the GIF images of PhotoshopCS3 and a description of the MMS format. it mainly introduces how to set the animated image format as GIF, the author also explains how to create GIF animation in the popular mobile phone MMS. I hope you will gain some benefits after reading it. The webpage design extension tutorial also contains a description of the image format, but does not repeat the section. This article describes the GIF image overview of Photoshop CS3 and the MMS format tutorial, this article mainly introduces how to set the animated image format as GIF. The author also describes how to create GIF animation in the popular mobile phone MMS. I hope you will gain some benefits after reading it.
The webpage design extension tutorial also describes the image format, but does not repeat the knowledge about GIF in this lesson. Instead, it introduces the features of other image formats and the comprehensive use methods. Therefore, if you want to learn the webpage design extension tutorial, you must master the content of this course.
Now we have learned a lot about how to make animations, but we are still not very clear about the final presentation form of animations. How can an animation be output? Where can I use it? What are precautions for use? In this lesson, we will discuss these issues in detail.
Currently, the main animated image format on Windows is GIF, which can be displayed directly on webpages. it is currently the most widely used animated image format. Animations in popular mobile phone MMs are also in GIF format. GIF formats support static and animated representations. Whether static or animated, the features are the same.
The implementation principle of animated GIF format is not complex. you can understand it as combining multiple static images (frames) to display them in turn. There is also an operational relationship between these images (frames). similar to the operations on the path of the selected area, these operations are addition, subtraction, and elimination. This is to optimize the number of animation bytes.
If a frame is added, the content of the frame is added to the image of the previous frame to form a new image. A common progress bar animation is a typical one, as shown in. suppose a progress bar consists of three frames. in our eyes, we can see the theoretical frame form, it seems that the three frames respectively save the image with the shortest, moderate, and longest progress bars. But in fact, the 2nd frame only contains the pixels of the part not included in the 1st frame, and then acts on the 1st frame as an addition to form a "1 2" image. The same is true for 3rd frames. This optimization can effectively reduce the number of bytes of the image.
The subtraction method is the opposite. it is used to erase certain pixels from the previous frame of the image and can be understood by the "regressing progress bar. The method of elimination is to completely erase the previous frame, which is mainly used when there is no association between the two frames. for example, when the whole frame is changed from red to green, there is no pixel between the two frames, then, the elimination method is adopted.
In actual production, Photoshop automatically determines the method based on the image situation without manual intervention. These calculation methods can be understood as a knowledge. It can also be used as a reference for animation conception.
The following is an important feature of the GIF format: the number of colors. a GIF can only support up to 256 colors, that is, a GIF image can contain up to 256 colors. This is especially evident in static GIF. some images with rich colors, such as gradient of multiple colors, are difficult to perfectly present in GIF. As shown in the left figure below, the image is partial (note that it is partial, not a complete full image) in the PNG24 bits, GIF256 no imitation color and diffuse imitation color. The full picture shows a shop window shot in Venice, as shown in the right figure below.
We can see that the PNG24 bits have the best color and can be seen as the source image. However, the color of GIF format is not expressive. In the case of no imitation color, some parts of the original image with color transition appear colored spots. In the case of diffuse imitation colors, the color spots are reduced, but the particle sensation is heavier, which is caused by the principle of imitation colors. You have already introduced the concept of imitation colors in the basic tutorial. you can click here to view the corresponding content.
Note that 256 colors refer to the entire image. If the size of the original image is the same as that, the difference between the 256 color and the original image is not great. This is because when the color is reduced to 256 colors, Photoshop will orchestrate the color based on the color in the original image. this process is also called index, which combines similar colors into one.
