By literally, animation means to bring something into life. An animation covers all possible changes that have visual effect and the visual effects can be different in nature. It might include time varying positions (motion dynamics), shape, color, transparency, structure and texture of an object (update dynamics), changes in lightening, camera position, orientation and focus.
A computer based animation is on animation performed by a computer using graphical tools to provide visual effects. A computer based animation includes the given four basic steps:

1. Input process: 

It is the first stage before the animation. The image of object must be digitized or drawing should be completed before the animation process. These can be done by optical scanning or tracing the drawing with a data tablet or producing the drawings by the use of drawing application or programs. The drawing may need to be post processed (filtered) to clean up any glitches arising from the input process. The digitize image should be kept in the key frames at extreme or characteristics position which has to be animated.

2. Composition stage: 

Foreground and background figures and colors are combined to generate the individual frames for the final animation in this stage. Several low resolution frames are place in a rectangular array to generate a trial film using pan zoom, features available in frame buffers. The frame buffer can take a particular portion of such an image (pan) and then enlarge it the entire screen (zoom). This process can be repeated on several frames of animation stored in the single image. If it is done fast enough, it gives the effect of continuity for animation.

3. In-between process: 

The animation of movement from one position to another position needs a composition of frames with intermediate position in-between the key frames. This is called in-between process it is created out by interpolation method, in this process systems gets only the starting and ending position. The easiest interpolation method is linear Interpolation called leaping, it has the limitations. For example if leaping is used to calculate intermediate position of a thrown ball in the air using the sequence of 3 key frames, starting mid and final position, then it will not helped. In such situation splines are used. Splines can be used to vary any parameter smoothly as a function of time. It can make an individual point move smoothly in space and time, in-between process also involves interpolation of objects shape in immediate frames.

4. Changing colors: 

For changing color, computer based animation, usages CLUT (color lookup table) in a frame buffer and the process of double buffering. The LUT animation is generated by manipulating the color lookup table. The simplest method is to cycle the colors in the LUT. Thus changing the color of various pieces of the image, using LUT animation is faster than sending an entire new pixmap to the frame buffer or each frame.


For example 8 color bits per pixel in 640*512 frame buffer, a single image contains 320 kilobytes of information. Transferring a new image in every 1/30th second to the buffer required a bandwidth of 9mbps where as LUT needs a few hundred to few thousands bytes.