181. Which of the following is/are used as basic function in nonlinear filter for noise reduction?
a. Computation of variance
b. Computation of median
c. All of the mentioned
d. None of the mentioned
Answer: (b).Computation of median

182. In neighborhood operation for spatial filtering if a square mask of size n*n is used it is restricted that the center of mask must be at a distance ≥ (n – 1)/2 pixels from border of image, what happens to the resultant image?
a. The resultant image will be of same size as original image
b. The resultant image will be a little larger size than original image
c. The resultant image will be a little smaller size than original image
d. None of the mentioned
Answer: (c).The resultant image will be a little smaller size than original image

183. Which of the following method is/are used for padding the image?
a. Adding rows and column of 0 or other constant gray level
b. Simply replicating the rows or columns
c. All of the mentioned
d. None of the mentioned
Answer: (c).All of the mentioned

184. In neighborhood operation for spatial filtering using square mask of n*n, which of the following approach is/are used to obtain a perfectly filtered result irrespective of the size?
a. By padding the image
b. By filtering all the pixels only with the mask section that is fully contained in the image
c. By ensuring that center of mask must be at a distance ≥ (n – 1)/2 pixels from border of image
d. None of the mentioned
Answer: (c).By ensuring that center of mask must be at a distance ≥ (n – 1)/2 pixels from border of image

185. Which of the following fact(s) is/are true for the relationship between low frequency component of Fourier transform and the rate of change of gray levels?
a. Moving away from the origin of transform the low frequency corresponds to smooth gray level variation
b. Moving away from the origin of transform the low frequencies corresponds to abrupt change in gray level
c. All of the mentioned
d. None of the mentioned
Answer: (c).All of the mentioned

186. Which of the following fact(s) is/are true for the relationship between high frequency component of Fourier transform and the rate of change of gray levels?
a. Moving away from the origin of transform the high frequency corresponds to smooth gray level variation
b. Moving away from the origin of transform the higher frequencies corresponds to abrupt change in gray level
c. All of the mentioned
d. None of the mentioned
Answer: (b).Moving away from the origin of transform the higher frequencies corresponds to abrupt change in gray level

187. What is the name of the filter that multiplies two functions F(u, v) and H(u, v), where F has complex components too since is Fourier transformed function of f(x, y), in an order that each component of H multiplies both real and complex part of corresponding component in F?
a. Unsharp mask filter
b. High-boost filter
c. Zero-phase-shift-filter
d. None of the mentioned
Answer: (c).Zero-phase-shift-filter

188. To set the average value of an image zero, which of the following term would be set 0 in the frequency domain and the inverse transformation is done, where F(u, v) is Fourier transformed function of f(x, y)?
a. F(0, 0)
b. F(0, 1)
c. F(1, 0)
d. None of the mentioned
Answer: (a).F(0, 0)

189. What is the name of the filter that is used to turn the average value of a processed image zero?
a. Unsharp mask filter
b. Notch filter
c. Zero-phase-shift-filter
d. None of the mentioned
Answer: (b).Notch filter

190. Which of the following filter(s) attenuates high frequency while passing low frequencies of an image?
a. Unsharp mask filter
b. Lowpass filter
c. Zero-phase-shift filter
d. All of the mentioned
Answer: (b).Lowpass filter

prepbytes affliate link