CS 107: Pictures and Sounds: Programming with Multimedia

Kalamazoo College

Spring 2008

Problem Set from Chapter 4

  1. Problems 4.2, 4.3.

  2. Problem 3.2. (Yes, look back at this problem from chapter 3.)

  3. Consider the following code to scale a picture to 1/4 its original size. Is there a difference between this code and the code that was actually in the Mini-Lab? Which pixels do each of them use to get the color to copy into the new picture? Are they the same? 
      def quarter(picture):
    newWidth = getWidth(picture)/2
    newHeight = getHeight(picture)/2
    canvas = makeEmptyPicture(newWidth, newHeight)
    for x in range(2, getWidth(picture)+1, 2):
      for y in range(2, getHeight(picture)+1, 2):
        p = getPixel(picture,x,y)
        c = getColor(p)
        setColor(getPixel(canvas, x/2, y/2),c)
    return canvas