1. Who introduced the concept of erosion in morphological image processing?
(A) John Mather
(B) Jean Serra
(C) David Marr
(D) Rafael Gonzalez
2. What operation is used to shrink the boundaries of foreground regions in a binary image?
(A) Dilation
(B) Erosion
(C) Opening
(D) Closing
3. Which morphological operation is primarily used to grow or thicken objects in a binary image?
(A) Dilation
(B) Erosion
(C) Opening
(D) Thresholding
4. Which operation is defined as erosion followed by dilation?
(A) Opening
(B) Closing
(C) Gradient
(D) Hit-or-Miss
5. What is the result of applying dilation followed by erosion?
(A) Opening
(B) Erosion
(C) Closing
(D) Boundary extraction
6. Which morphological operation helps in removing small objects or noise from the foreground?
(A) Dilation
(B) Closing
(C) Opening
(D) Thresholding
7. Which operation is suitable for filling small holes or gaps in objects?
(A) Erosion
(B) Opening
(C) Closing
(D) Subtraction
8. Which of the following is not a basic morphological operation?
(A) Dilation
(B) Erosion
(C) Thresholding
(D) Opening
9. In dilation, what happens to the white (foreground) regions?
(A) They shrink
(B) They remain unchanged
(C) They expand
(D) They vanish
10. Which operation is used when we want to eliminate thin protrusions from objects?
(A) Dilation
(B) Opening
(C) Closing
(D) Morphological gradient
11. What is the role of the structuring element in morphological operations?
(A) It acts as a filter
(B) It defines the shape and size of the operation
(C) It converts grayscale to binary
(D) It performs edge detection
12. What is the typical shape used for structuring elements?
(A) Line
(B) Circle
(C) Square
(D) All of the above
13. Which of the following is used to smooth the contour of objects?
(A) Erosion
(B) Dilation
(C) Opening and Closing
(D) Sobel Filter
14. What is the effect of erosion on isolated pixels in a binary image?
(A) They are preserved
(B) They expand
(C) They are removed
(D) They turn gray
15. Which morphological operation is used to highlight boundaries of objects?
(A) Dilation
(B) Morphological gradient
(C) Erosion
(D) Top-hat
16. In closing operation, the dilation step is followed by:
(A) Thresholding
(B) Erosion
(C) Another Dilation
(D) Opening
17. Which operation is used to bridge narrow breaks and long thin gulfs?
(A) Opening
(B) Closing
(C) Dilation
(D) Hit-or-Miss
18. What happens when erosion is applied repeatedly?
(A) Objects grow
(B) Objects get disconnected
(C) Noise is added
(D) Holes are filled
19. What is the dual operation of opening?
(A) Closing
(B) Dilation
(C) Erosion
(D) Gradient
20. Which operation helps to remove background noise while preserving the shape of objects?
(A) Dilation
(B) Opening
(C) Erosion
(D) Histogram Equalization
21. Which combination can be used to remove noise and fill holes simultaneously?
(A) Opening and Closing
(B) Dilation and Erosion
(C) Gradient and Threshold
(D) Median and Average filter
22. Which morphological operation is more sensitive to small structures?
(A) Dilation
(B) Erosion
(C) Closing
(D) Opening
23. What is the basic requirement for performing morphological operations?
(A) Binary image
(B) RGB image
(C) Grayscale image
(D) Color histogram
24. Which operation is most suitable for extracting thin lines?
(A) Dilation
(B) Skeletonization
(C) Closing
(D) Thresholding
25. Which of the following is not an effect of dilation?
(A) Filling small holes
(B) Connecting close objects
(C) Removing small white noise
(D) Expanding boundaries
26. What happens if erosion is applied to the background instead of the foreground?
(A) Background shrinks
(B) Foreground shrinks
(C) Foreground expands
(D) Image inverts
27. What is the output of opening on an image with small bright spots and large dark regions?
(A) Bright spots preserved
(B) Bright spots removed
(C) Dark regions eliminated
(D) Image unchanged
28. What is a primary application of morphological operations?
(A) Image encryption
(B) Object shape analysis
(C) Frequency transformation
(D) Histogram plotting
29. What is the effect of increasing the size of the structuring element during dilation?
(A) Smaller expansion
(B) Greater expansion
(C) No change
(D) More noise
30. Which operation would most likely disconnect thin joints between objects?
(A) Dilation
(B) Erosion
(C) Opening
(D) Closing
31. Which operation is defined as the difference between dilation and erosion?
(A) Top-hat
(B) Morphological gradient
(C) Hit-or-Miss
(D) Watershed
32. Which of the following operations is not used for pre-processing?
(A) Dilation
(B) Closing
(C) Fourier Transform
(D) Opening
33. Which operation is effective in removing salt noise from a binary image?
(A) Erosion
(B) Dilation
(C) Opening
(D) Closing
34. Which operation is best to remove pepper noise from a binary image?
(A) Erosion
(B) Dilation
(C) Closing
(D) Opening
35. Which sequence of operations is applied in the closing method?
(A) Erosion → Dilation
(B) Dilation → Erosion
(C) Erosion → Opening
(D) Dilation → Threshold
36. Which is true about morphological operations?
(A) They are linear
(B) They preserve grayscale intensities
(C) They operate on shape and structure
(D) They work only in frequency domain
37. The main goal of opening is to:
(A) Remove dark noise
(B) Remove light noise
(C) Remove small bright objects
(D) Connect background regions
38. What is a hit-or-miss operation used for?
(A) Edge detection
(B) Pattern matching
(C) Noise removal
(D) Brightness adjustment
39. Which operation would best highlight cracks or thin lines in material images?
(A) Closing
(B) Dilation
(C) Morphological gradient
(D) Skeletonization
40. A typical application of closing is:
(A) Object segmentation
(B) Hole filling
(C) Boundary detection
(D) Noise reduction
41. Which of the following does not require a structuring element?
(A) Erosion
(B) Opening
(C) Dilation
(D) Histogram equalization
42. Which morphological operation can disconnect objects connected by thin lines?
(A) Closing
(B) Dilation
(C) Opening
(D) Gradient
43. Which morphological operation is suitable for extracting boundaries?
(A) Gradient
(B) Closing
(C) Skeletonization
(D) Erosion
44. The combination of dilation and erosion results in:
(A) Gradient
(B) Opening or Closing
(C) Thresholding
(D) Smoothing
45. The term “morphology” in image processing is derived from:
(A) Physics
(B) Biology
(C) Chemistry
(D) Mathematics
46. Which operation does not generally change the overall shape but removes minor protrusions?
(A) Erosion
(B) Opening
(C) Dilation
(D) Histogram equalization
47. Which of the following combinations improves both small noise removal and gap filling?
(A) Dilation → Closing
(B) Opening → Closing
(C) Threshold → Dilation
(D) Erosion → Opening
48. What happens to holes inside objects after closing?
(A) They increase
(B) They decrease
(C) They fill
(D) They shrink
49. Which operation is best for removing small black spots in white foreground?
(A) Dilation
(B) Closing
(C) Erosion
(D) Opening
50. What is the main idea behind using morphological operations in image processing?
(A) Noise enhancement
(B) Shape manipulation
(C) Color matching
(D) Compression
