Q1. A color image is formed by a combination of ________ colors?
Red, Green, and Blue
Black, and White
Red, Green, and White
All colors
Answer: 1 Explanation: A color image has 3 channels that contains the intensity information corresponding to three wavelengths red, green, and blue (RGB) collectively called primary colors or channels.
Q2. In spatial filtering, we convolve the neighborhood of a pixel with a subimage. What we generally call this subimage?
mask
kernel
filter
All of the above
Answer: 4 Explanation: We refer to this subimage by all of the above mentioned names.
Q3. Which of the following interpolation algorithms results in a blocky or pixelated image?
Nearest Neighbor
Bilinear
Bicubic
None of the above
Answer: 1 Explanation: Because in Nearest Neighbor we are only replicating the nearest pixel value so this results in a blocky or pixelated image. To know more about Nearest Neighbor, refer to this link.
Q4. Does Sobel filter have some smoothing effect?
Yes
No
Answer: 1 Explanation: Because Sobel filter is obtained by multiplying the x, and y-derivative filters with some smoothing filter(1D) so this has some smoothing effect.
Q5. Which of the following arithmetic operations can be used for Image Enhancement?
Image Averaging
Image Subtraction
Image Multiplication
All of the above
Answer: 4 Explanation: All the arithmetic operations such as Averaging, subtraction or multiplication can be used for image enhancement. For instance, Averaging can be used for noise removal, subtraction can be used for detecting blockage or moving objects and multiplication can be used for extracting region of interest (roi) using masking etc.
Q6. Suppose we plot the 2D color histogram for Red and Green channels. So, what does each point within this histogram represents?
Frequency corresponding to each Red and Green pair
Pixel location corresponding to each Red and Green pair
Intensity value of the Red color
Intensity value of the Green color
Answer: 1 Explanation: For the above case, Y and X-axis correspond to the Red and Green channel ranges( for 8-bit, [0,255]) and each point within the histogram shows the frequency corresponding to each Red and Green pair. To know more about 2D Image Histograms, refer to this link.
Q7. A 0 degree hue results in which color?
Red
Green
Blue
White
Answer: 1 Explanation: A 0 degree hue results in Red color. Refer to this link to know more.
Q8. What response does a first order derivative filter will give for flat regions in an image?
Zero
positive
negative
Answer: 1 Explanation: As we know that the differentiation of a constant is 0. Since the flat region has nearly constant intensity so the first order derivative filter will give 0 response.