Digital Signal Processing - May 2012

Computer Engineering (Semester 7)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Justify/Contradict the following statements:

1(a) Laplacian is better than gradient for detection of edges.(5 marks) 1(b) For digital image having salt and pepper noise, median filter is the best filter.(5 marks) 1(c) Unit Ramp signal is neither Energy nor Power Siginal.(5 marks) 1(d) Lossy compression is not suitable for compressing executable files.(5 marks) 2(a) Peform Histogram Equalization for following. Obtain a plot of original as well as the Equalized Histogram

(10 marks) 2(b) A causal FIR system have 3 cascade blocks, first two have independent impulse responses h₁(n)={1,2,2} & h₂(n)=u(n)-u(n-2). Find the impulse response of 3rd block h₃(n) if an overall impulse response is h(n)={2,5,6,3,2,2}(10 marks) 3(a) Explain in detail enhancement techniques in Spatial Domain used for images.(8 marks) 3(b) Explain homomorphic filtering in detail.(6 marks) 3(c) Find the DFT of the given image

(6 marks) 4(a) Define the following:
(i) Eucledean distance
(ii) City block distance
(iii) Chess board distance.
(iv)m conectivity(10 marks) 4(b) Find DFT of given sequence (Use DITFFT Algorithm) x(n)={1,2,3,4,4,3,2,1}(10 marks) 5(a) Explain the method of segmentation of images by region splitting and merging.(10 marks) 5(b) Given below is the table of 8 symbols and their freq of occurance give Huffman code for each symbol

(10 marks) 6(a) Perform the convolution of the following two sequences using Z transform

(8 marks) 6(b) Find inverse Z-Transform

(6 marks) 6(c) What is the difference between image restoration and image enhancement? What do they have in common?(6 marks)

Write short notes on :-

7(a) Discrete Cosine Transform(5 marks) 7(b) Sampling and Quantisation(5 marks) 7(c) Hough Transform(5 marks) 7(d) Wavelet Transform(5 marks)