14.4. Posterizing¶

The process of changing an image so it only uses a small number of colors is known as posterizing (old posters had to be printed with a small number of colors - the technology didn’t let one make complex blends).

This time, we need to make a function that will force a color value between 0 and 255 to become one of a few specific options.

Write code to return 0 if colorValue is less than 50, 125 if it is 50-124, and 255 otherwise.

Now that you have that function, add it to this program to see it in action:

Rewrite the code for posterizing an image using if and else rather than multiple if’s. Test that it still works correctly.

How many different colors are possible in our image after we posterize it using this function?

8
Two possible values of each of red, green, and blue (3 colors) is 2 raised to 3rd power combinations which is 8.
3
Two values of each of red, green, and blue is more than 3.
120
Far fewer
16,777,216 (= 256 * 256 * 256)
That's the total number of colors possible if each channel can be 0-255. But this code reduces that.