CMPT 165 Lecture Notes - Lecture 16: Lossy Compression, Compression Ratio, Alpha Compositing

• School: Simon Fraser University
• Department: Computing Science
• Course: CMPT 165
• Professor: Ying Tang

Document Summary

Transparency: the amount of light that can pass through, high transparency = low opacity. Opacity: the amount of light absorbed, hihg opacity = low transparency, don"t store at all, transparent pixels are off, extra channel (8 bit per pixel, known as alpha channel, rgb alpha, different transparency intensity (allows you to fade) If you have a 24 bit image, you store an additional bit for this (24 bits +1 = 25 bits) Animation: motion achieved by multiple static frames in a single file, gif and png support this, jpeg does not. ****exam questions on mapping****** (draw tree diagram too) Body -> img -> map > area x3 (on the same level) ***know this: svg = scalable variable graphic, factors give you directions and gives you a line. Svg: scalability, can hadle a growing amount of work easily, draw a purple line (-1,1. In the 2 arrow example, there is a lot of redundant pixel information.