# Intensity Transformation MCQ [Free PDF] – Objective Question Answer for Intensity Transformation Quiz

42. Sharpening is analogous to which of the following operations?

A. To spatial integration
B. To spatial differentiation
C. All of the mentioned
D. None of the mentioned

Smoothing is analogous to integration and so, sharpening to spatial differentiation.

43. Which of the following fact(s) is/are true about sharpening spatial filters using digital differentiation?

A. Sharpening spatial filter response is proportional to the discontinuity of the image at the point where the derivative operation is applied
B. Sharpening spatial filters enhances edges and discontinuities like noise
C. Sharpening spatial filters deemphasizes areas that have slowly varying gray-level values
D. All of the mentioned

The derivative operator’s response is proportional to the discontinuity of the image at the point where the derivative operation is applied.
Image differentiation enhances edges and discontinuities like noise and deemphasizes areas that have slowly varying gray-level values.
Since sharpening spatial filters are analogous to differentiation, so, all the above-mentioned facts are true for sharpening spatial filters.

44. Which of the facts(s) is/are true for the first-order derivative of a digital function?

A. Must be nonzero in the areas of constant grey values
B. Must be zero at the onset of a gray-level step or ramp discontinuities
C. Must be nonzero along the gray-level ramps
D. None of the mentioned

The first-order derivative of a digital function is defined as:

• Must be zero in the areas of constant grey values.
• Must be nonzero at the onset of a gray-level step or ramp discontinuities.
• Must be nonzero along the gray-level ramps.

45. Which of the facts(s) is/are true for the second-order derivative of a digital function?

A. Must be zero in the flat areas
B. Must be nonzero at the onset and end of a gray-level step or ramp discontinuities
C. Must be zero along the ramps of constant slope
D. All of the mentioned

The second-order derivative of a digital function is defined as:
Must be zero in the flat areas i.e. areas of constant grey values.
Must be nonzero at the onset of a gray-level step or ramp discontinuities.
Must be zero along the gray-level ramps of constant slope.

46. The derivative of a digital function is defined in terms of difference. Then, which of the following defines the first-order derivative ∂f/∂x= ___________ of a one-dimensional function f(x)?

A. f(x+1)-f(x)
B. f(x+1)+ f(x-1)-2f(x)
C. All of the mentioned depend upon the time when partial derivative will be dealt along two spatial axes
D. None of the mentioned

The definition of the first-order derivative of a one-dimensional image f(x) is:
∂f/∂x= f(x+1)-f(x), where the partial derivative is used to keep the notation same even for f(x, y) when the partial derivative will be dealt along two spatial axes.

47. The derivative of a digital function is defined in terms of difference. Then, which of the following defines the second-order derivative ∂2 f/∂x2 = ___________ of a one-dimensional function f(x)?

A. f(x+1)-f(x)
B. f(x+1)+ f(x-1)-2f(x)
C. All of the mentioned depend upon the time when partial derivative will be dealt along two spatial axes
D. None of the mentioned

The definition of a second-order derivative of a one-dimensional image f(x) is:
(∂2 f)/∂x2 =f(x+1)+ f(x-1)-2f(x), where the partial derivative is used to keep notation same even for f(x, y) when partial derivative will be dealt along two spatial axes.

48. What kind of relationship can be obtained between the first-order derivative and second-order derivative of an image having a based on edge productions that show a transition like a ramp of the constant slope?

A. First-order derivative produces a thick edge while second-order produces a very fine edge
B. Second-order derivative produces a thick edge while first-order produces a very fine edge
C. Both first and second-order produce a thick edge
D. Both first and second-order produce a very fine edge

The first-order derivative remains nonzero along the entire ramp of constant slope, while the second-order derivative remains nonzero only at the onset and end of such ramps.

If an edge in an image shows transition like the ramp of constant slope, the first-order and second-order derivative values show the production of thick and finer edges respectively.

49. What kind of relationship can be obtained between the first-order derivative and second-order derivative of an image on the response obtained by encountering an isolated noise point in the image?

A. First-order derivative has a stronger response than a second order
B. Second-order derivative has a stronger response than a first order
C. Both enhance the same and so the response is the same for both first and second-order derivative
D. None of the mentioned

The second-order derivative has a stronger response than a first-order relationship can be obtained between the first-order derivative and second-order derivative of an image on the response obtained by encountering an isolated noise point in the image.

This is because a second-order derivative is more aggressive toward enhancing sharp changes than first order.

50. What kind of relationship can be obtained between the response of the first-order derivative and second-order derivative of an image having a transition into a gray-level step from zero?

A. First-order derivative has a stronger response than a second order
B. Second-order derivative has a stronger response than a first order
C. Both first and second-order derivative has the same response
D. None of the mentioned

This is because a first-order derivative has a stronger response to a gray-level step than second order, but, the response becomes the same if the transition into the gray-level step is from zero.

51. If in an image there exist a similar change in gray-level values in the image, which of the following shows a stronger response using a second-order derivative operator for sharpening?

A. A-line
B. A step
C. A point
D. None of the mentioned

The second-order derivative shows a stronger response to a line than a step and a point than a line if there are similar changes in gray-level values in an image.

51. The principle objective of Sharpening, to highlight transitions is ________

A. Pixel density
B. Composure
C. Intensity
D. Brightness

The principal objective of Sharpening, to highlight transitions is Intensity. Sharpening is achieved using Spatial Differentiation.

52. How can Sharpening be achieved?

A. Pixel averaging
B. Slicing
C. Correlation
D. None of the mentioned

Sharpening is achieved using Spatial Differentiation. The principal objective of Sharpening, to highlight transitions is Intensity.

53. What does Image Differentiation enhance?

A. Edges
B. Pixel Density
C. Contours
D. None of the mentioned

Fundamentally, the strength of the response of a derivative operator is proportional to the degree of intensity discontinuity of the image at the point at which the operator is applied.

Thus, image differentiation enhances edges and other discontinuities (such as noise) and deemphasizes areas with slowly varying intensities.

54. What does Image Differentiation de-emphasize?

A. Pixel Density
B. Contours
C. Areas with slowly varying intensities
D. None of the mentioned

Image Differentiation de-emphasizes areas with slowly varying intensities.

55. The requirements of the First Derivative of a digital function:

A. Must be zero in areas of constant intensity
B. Must be non-zero at the onset of an intensity step
C. Must be non-zero along ramps
D. All of the Mentioned

The requirements of the First Derivative of a digital function:

A. Must be zero in areas of constant intensity
B. Must be non-zero at the onset of an intensity step
C. Must be non-zero along ramps

All three conditions must be satisfied.

56. What is the Second Derivative of Image Sharpening called?

A. Gaussian
B. Laplacian
C. Canny
D. None of the mentioned

The Second Derivative of Image Sharpening is also called Laplacian.

57. The ability that rotates the image and applies the filter gives the same result, as applying the filter to the image first, and then rotating it, is called _____________

A. Isotropic filtering
B. Laplacian
C. Rotation Invariant
D. None of the mentioned

It is called Rotation Invariant, although the process used is Isotropic filtering.

58. For a function f(x,y), the gradient of ‘f’ at coordinates (x,y) is defined as a ___________

A. 3-D row vector
B. 3-D column vector
C. 2-D row vector
D. 2-D column vector

For a function f(x,y), the gradient of ‘f’ at coordinates (x,y) is defined as a 2-D column vector.

59. Where do you find frequent use of Gradient?

A. Industrial inspection
B. MRI Imaging
C. PET Scan
D. None of the mentioned

The gradient is used in Industrial inspection, to aid humans, in the detection of defects.

60. Which of the following occurs in Unsharp Masking?

A. Blurring original image
C. Subtracting blurred images from the original
D. All of the mentioned