Assignment 2

CSE 130 Spring Quarter, 2009

Read Chapter 4, Chapter 5, and Chapter 6. Also, review the material on histogram equalization in Chapter 3.
Consider the following monochrome image whose 4-bit pixels are allowed to range from 0 to 15. As you can see, most of the pixels are towards the low end of the range and are therefore relatively dark. Perform histogram equalization on this image. Show (a) the original histogram (done for you), (b) the original's cumulative histogram, (c) the ideal cumulative histogram, (d) the equalized cumulative histogram, (e) the equalized histogram, (f) the mapping of pixel values from the original range to the new values, and (g) the equalized image. 
2  0  8  1

5  3  4  3

4  5  7  6

2  7  6  9

original histogram
      X  X  X  X  X  X
X  X  X  X  X  X  X  X  X  X
0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15

which can also be represented as
1  1  2  2  2  2  2  2  1  1  0  0  0  0  0  0
0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15
At the end of Chapter 4, do exercises 1 through 10.
At the end of Chapter 5, do exercises 1 through 6.
On the computer, using PixelMath, prepare your own version of each of the following effects. For each one, include the Source image, Destination image, and the formula used to produce it.
  • Hue rotation (the amount should be either 1/3, 1/2, or 2/3);
  • Start with a monochrome image. (You may convert a color image of your own to monochrome.) Create a false-color version of it by inventing a formula that sets the hue of the new image to a value between 0 and 1 depending on how bright the Source1 pixel value is. Assume that saturation and value (in the HSV system) are to be set to 1.0 no matter what the source1 pixel value is;
  • Color saturation boost (use a formula that makes the saturation value for each pixel half the distance to 1.0 of what it was. For example, a saturation value of 0.4 would be transformed to a saturation value of 7.0 in the destination image, and 0.0 would get mapped to 0.5, etc.);
    • Prepare your solutions as a document using one of the following: Microsoft Word, Google Docs, or Open Office Writer. Submit your document as a pdf formatted file. The document should be turned in electronically using Catalyst CollectIt.
    Due Wednesday, April 15, at 11:30 PM. (Catalyst will accept it until 11:45 without marking it late.)