Multiple If’s with Images¶
We can use multiple if’s to reduce the number of colors in an image. Let’s say that if we have a little bit of each of red, green, and blue, we want to make each of them zero. If we have more, we set them to a midrange value like 120. This is called posterizing because it reduces all the colors in a picture to a small number of colors – like the ones you might use if you were making a poster.
Rewrite the code for posterizing an image using if and else rather than multiple if’s. Test that it still works correctly.

csp1541: How many different colors will be in our image when we are done?
 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. But this code reduces that.