Lab Report

In your lab write-up, include an introduction and conclusion, keeping in mind the following general points:

Also answer the following questions:

All Images

  1. Print your binary output images on a laser printer to see how they would appear in a (low cost) newsletter. Comment on how they compare to grayscale images you see in a local newspaper. Include these printouts in your lab report.

Images A1 and A2: Dithering Matrix

Images A1 and A2 should look like the original, but will contain some artifacts.

  1. What artifacts are present? How do they differ between the two images?

  2. Which image is perceptually more similar to the original image? Why/why not? Explain your answer in terms of frequency content, attainable apparent bit depth, and human visual perception.

Image B: Error Diffusion

  1. Why is it not desirable to display low frequency error when using error diffusion? (c.f. Lab2 results showing how information is distributed in the frequency domain.)

  2. Compute the MSE between the halftoned image and the original grayscale image for each of the 3 methods you implemented. How does MSE compare with visual quality? Why?

  3. In terms of minimizing MSE, what is theoretically the best halftoning algorithm for any image. Prove your claim. What is the lowest attainable MSE for the image you used.