11. Which of the following comes under the application of image blurring?
A. Object detection
B. Gross representation
C. Object motion
D. Image segmentation
Answer: B
An important application of spatial averaging is to blur an image to get a gross representation of interesting objects, such that the intensity of the small objects blends with the background and large objects become easy to detect. [/bg_collapse]
12. Which of the following filter’s responses is based on the ranking of pixels?
A. Nonlinear smoothing filters
B. Linear smoothing filters
C. Sharpening filters
D. Geometric mean filter
13. Median filter belongs to which category of filters?
A. Linear spatial filter
B. Frequency domain filter
C. Order static filter
D. Sharpening filter
Answer: C
The median filter belongs to order static filters, which, as the name implies, replaces the value of the pixel by the median of the grey levels that are present in the neighborhood of the pixels. [/bg_collapse]
14. Median filters are effective in the presence of impulse noise.
A. True
B. False
15. What is the maximum area of the cluster that can be eliminated by using an n×n median filter?
A. n2
B. n2/2
C. 2*n2
D. n
Answer: B
Isolated clusters of pixels that are light or dark with respect to their neighbors, and whose area is less than n2/2, i.e., half the area of the filter, can be eliminated by using an n×n median filter. [/bg_collapse]
16. Which of the following expression is used to denote spatial domain process?
A. g(x,y)=T[f(x,y)]
B. f(x+y)=T[g(x+y)]
C. g(xy)=T[f(xy)]
D. g(x-y)=T[f(x-y)]
17. Which of the following shows three basic types of functions used frequently for image enhancement?
A. Linear, logarithmic, and inverse law
B. Power-law, logarithmic, and inverse law
C. Linear, logarithmic and power-law
D. Linear, exponential, and inverse law
Answer: B
The introduction to gray-level transformations shows three basic types of functions used frequently for image enhancement: linear (negative and identity transformations), logarithmic (log and inverse-log transformations), and power-law (nth power and nth root transformations). The identity function is the trivial case in which output intensities are identical to input intensities. It is included in the graph only for completeness. [/bg_collapse]
18. Which expression is obtained by performing the negative transformation on the negative of an image with gray levels in the range[0, L-1]?
A. s=L+1-r
B. s=L+1+r
C. s=L-1-r
D. s=L-1+r
Answer: C
The negative of an image with gray levels in the range[0, L-1] is obtained by using the negative transformation, which is given by the expression: s=L-1-r. [/bg_collapse]
19. What is the general form of representation of log transformation?
A. s=clog10(1/r)
B. s=clog10(1+r)
C. s=clog10(1*r)
D. s=clog10(1-r)
Answer: B
The general form of the log transformation: s=clog10(1+r), where c is a constant, and it is assumed that r ≥ 0. [/bg_collapse]
20. What is the general form of representation of power transformation?
A. s=crγ
B. c=srγ
C. s=rc
D. s=rcγ
21. What is the name of the process used to correct the power-law response phenomena?
A. Beta correction
B. Alpha correction
C. Gamma correction
D. Pie correction
Answer: C
A variety of devices used for image capture, printing, and display respond according to a power law. By convention, the exponent in the power-law equation is referred to as gamma. The process used to correct these power-law response phenomena is called gamma correction. [/bg_collapse]
22. Which of the following transformation function requires much information to be specified at the time of input?
A. Log transformation
B. Power transformation
C. Piece-wise transformation
D. Linear transformation
Answer: C
The practical implementation of some important transformations can be formulated only as piecewise functions. The principal disadvantage of piecewise functions is that their specification requires considerably more user input. [/bg_collapse]
23. In contrast to stretching, if r1=s1 and r2=s2 then which of the following is true?
A. The transformation is not a linear function that produces no changes in gray levels
B. The transformation is a linear function that produces no changes in gray levels
C. The transformation is a linear function that produces changes in gray levels
D. The transformation is not a linear function that produces changes in gray levels
Answer: B
The locations of points (r1,s1) and (r2,s2) control the shape of the transformation function. If r1=s1 and r2=s2 then the transformation is a linear function that produces no changes in gray levels. [/bg_collapse]
24. In contrast to stretching, if r1=r2, s1=0, and s2=L-1 then which of the following is true?
A. The transformation becomes a thresholding function that creates an octal image
B. The transformation becomes an override function that creates an octal image
C. The transformation becomes a thresholding function that creates a binary image
D. The transformation becomes a thresholding function that does not create an octal image
Answer: C
If r1=r2, s1=0 and s2=L-1,the transformation becomes a thresholding function that creates a binary image. [/bg_collapse]
25. In contrast to stretching, if r1≤r2 and s1≤s2 then which of the following is true?
A. The transformation function is double valued and exponentially increasing
B. The transformation function is double valued and monotonically increasing
C. The transformation function is single-valued and exponentially increasing
D. The transformation function is single-valued and monotonically increasing
Answer: D
The locations of points (r1,s1) and (r2,s2) control the shape of the transformation function. If r1≤r2 and s1≤s2 then the function is single-valued and monotonically increasing. [/bg_collapse]