Lab Report

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

Also answer the following questions in your report:

Questions for Part 1

  1. Compare each of the interpolation methods of part 1 and describe the theory and usefulness of each one.

  2. Does it matter if you interpolate along the rows first instead of along the columns first? If it does matter, show an example of a 2x2 block that would be interpolated into two different 4x4 blocks depending on the order. If it does not matter, prove it mathematically. Answer this question for Part 1, Method B (bilinear interpolation).

Questions for Part 2:

  1. What is the mean squared error (MSE) for each restored image?

  2. Compare the four restored images you obtained. Using your (subjective) judgment, rank the images from best to worst according to the visual quality of the interpolated output images.

  3. How is the subsampling rate related to the MSE? Why?

  4. What difference does an anti-aliasing filter make? Why?

  5. Is the MSE correlated with your subject evaluation? Why/why not?

  6. The methods B and D are equivalent to convolving the input image with an "ideal interpolation" sinc function, then sub-sampling, both done in the spatial domain. Explain why this method would give you the same results.

Overall Questions

  1. Why is the distortion in the letters more apparent than the distortion in the cats when subsampling in Method A?

  2. Compare the subsampled images obtained by using Methods A and B (i.e., with and without an anti-aliasing filter) - where is the main difference apparent? Why?