Image Processing - May 2015

Information Technology (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.

1 (b) Extreme contrast straching is thresholding. (5 marks)

1 (c) Explain discrete time systems with example. (5 marks)

1 (d) Differentiate between spatial resolution & tonal resolution. (5 marks)

2 (a) x(t) = sin (480 πt) + 3sin(720 πt) is sampled with F_s=600 times per second.
i) What are the frequencies in radians in the resulting DT signal x[n]?
ii) If x[n] is passed through an ideal interpolator, what is the reconstructed signal. (10 marks)

2 (b) Perform following operations on given signal.
x(n)={1, 2, 3, 5}
i) x(-n -1)
ii) x(n-2)
iii) x(n+1)
iv) x(-n +2)
v) 2x(n). (10 marks)

3 (a) Obtain four directional chain code & shape representation of following image. (5 marks)

3 (b) "Classify the signal as energy or power signal $$ x(n) = \left\{\begin{matrix} \left ( \frac {1}{2} \right )^n & n \ge 0 \\ (2) ^n & n \le 0 \end{matrix}\right. $$" (5 marks)

3 (c) "Consider the image given below. Calculate direction of edge at the centre point of image. $$ I = \begin{bmatrix} 50 &80 &70 \\5 &50 &90 \\7 &9 &50 \end{bmatrix} $$" (10 marks)

4 (a) "For the following binary image perform morphological operation opening followed by closing. $$ A= \begin{matrix} 1 &0 &1 &0 &1 &0 &1 \\1 &1 &0 &1 &1 &0 &1 \\1 &1 &1 &1 & 1 &1 &1 \\1 &1 &1 &1 & 1&0 &0 \\1 &1 &0 &1 &1 &1 &1 \end{matrix} \ \ B = [(1) \ 1$$" (10 marks)

4 (b) Derive Fast Walsh Transform Flowgraph for N=4. (10 marks)

5 (a) If x[n]={1, 2, 3, 4} & h{n} = {1, 7}
Find linear convolution using circular convolution. (10 marks)

5 (b) Compare lossless and lossy comparison techniques. (5 marks)

5 (c) Object detecting using correlation principle. (5 marks)

Write short notes on any two:

6 (a) Digital watermarking with application. (5 marks)

6 (b) Sampling & quantizations. (5 marks)

6 (c) Explain various frequency domain law pass filters in detail. (5 marks)

7 (a) Perform histogram stretching 50 that the new image has a dynamic range of [0, 7].

7 (b) State & prove any four properties of DFT. (10 marks) 1 (a) Prove that Highpass: Original - Lowpass.(5 marks)