11.3. Understanding Image Representation

Understanding images requires understanding a set of abstractions:

1. Pictures are made up of little pixels, laid out on an (x,y) grid.

2. Each pixel contains a color.

3. Each color has a red part, a green part, and a blue part.

4. Each color part is actually a number between 0 and 255.

5. If a pixel has red=0, green=0, and blue=0 then the color is black since this is an absence of any color of light.

6. If a pixel as red=255, green=255, and blue=255 then the color is white. Try tilting the bottom of a cd in white light to see the colors in the light.

Figure: A grid with horizontal (x) and vertical (y) dimensions

There are some excellent CS Unplugged activities for understanding image and color representation.

Note

Discuss topics in this section with classmates.

Show Comments

You have attempted of activities on this page