Q1. Which of the following Morphological operations closes the holes/gaps present in the object while keeping the initial object size the same?
Dilation
Erosion
Closing
Opening
Answer: 3 Explanation: As clear from the name, Dilation dilates or expands the object region so for bridging/closing the holes Dilation can be used but to keep the initial object size same we need Erosion. Since Closing is Dilation followed by Erosion so this can also be used.
Q2. Which of the following OpenCV functions can be used to threshold an image?
cv2.threshold()
cv2.thresh()
cv2.Thresh()
cv2.Threshold()
Answer: 1 Explanation: In OpenCV, cv2.threshold() can be used to threshold an image. Refer to this link to know more.
Q3. Difference between the image and its opening is known as __________?
Black top-hat transform
White top-hat transform
Hit or Miss
Closing
Answer: 2 Explanation: Difference between the image and its opening is known as White top-hat transform. Refer to this link to know more.
Q4. What is the contrast in image processing?
the difference in luminance or color that makes an object distinguishable from other objects within the same field of view.
the difference in the resolution that makes an object distinguishable from other objects within the same field of view.
same as brightness
There is no such term in image processing!!!
Answer: 1 Explanation: In image processing, contrast refers to the difference in luminance or color that makes an object distinguishable from other objects within the same field of view. To know more about contrast, refer to this link.
Q5. Which of the following refers to a type of noise in an image?
Gaussian
Salt and Pepper
Speckle
All of the above
Answer: 4 Explanation: All of the above refers to a type of noise in an image.
Q6. Which of the following Morphological operations can be used for shape detection or finding particular patterns in the given image?
Morphological Gradient
Hit-or-Miss Transform
Top-hat Transform
Opening
Answer: 2 Explanation: Hit-or-Miss Transform can be used for shape detection or finding particular patterns in the given image. In this, we use two structuring elements (say B1 and B2) and ask a simple question of does B1 fits the object while, simultaneously, B2 misses the object, i.e. fits the background. Refer to this link to know more.
Q7. Which of the following matplotlib functions can be used to calculate the image histogram? Suppose we import as “import matplotlib.pyplot as plt”
plt.hist()
plt.calcHist()
plt.showHist()
plt.histCalc()
Answer: 1 Explanation: In matplotlib, plt.hist() can be used to calculate the image histogram. Refer to this link to know more about this function.
Q8. In Perspective Transformation, what is the minimum number of points to select to obtain the transformation matrix?
1
2
3
4
Answer: 4 Explanation: In Perspective Transformation, the transformation matrix (M) is defined by 8 constants, thus to find this matrix we need 4 points. Refer to this link to know more.