Question 4: 15 marks

a) Consider a hypothetical DWT Decomposition Level information given below for an image of size 1024x1024 pixels. Answer the following questions: 9 marks

Decomposition Level Approximation Coefficient Image Truncated Coefficients (%) Reconstruction Error (rms)

1 512x512 80% 3.42

2 256x256 92% 4.44

3 128x128 96% 4.56

4 64x64 96.5% 4.65

I. For compression, which decomposition level is best and which is the worst and why?

II. For image reconstruction, which decomposition level is best and which is the worst and why?

III. From computational burden consideration, which decomposition level is adequate and why?

b) What is the main difference between the coefficients of Averaging operation based masks compared to Differentiation operation based masks? What is the resulting effect on the images by these two types of masks? 6 marks