Virtual Labs

1. What is the main purpose of an image histogram?

a: To show the spatial position of every pixel Explanation

Explanation

b: To describe the distribution of pixel intensities Explanation

Explanation

c: To determine the image file format Explanation

Explanation

d: To record the sequence in which pixels were captured Explanation

Explanation

2. Which image operation changes the spatial arrangement of pixels without changing their gray-level values?

a: Adding a positive constant to every pixel Explanation

Explanation

b: Subtracting a constant from every pixel Explanation

Explanation

c: Rotating the image Explanation

Explanation

d: Applying a gray-level transformation Explanation

Explanation

3. In an 8-bit grayscale histogram, which gray-level range is normally represented?

0

255

Explanation

1

256

Explanation

0

256

Explanation

-255

255

Explanation

4. An image is transformed by adding the same positive constant to every pixel. Which change in its histogram is expected?

a: A shift toward lower gray levels Explanation

Explanation

b: No change in gray-level positions Explanation

Explanation

c: A shift toward higher gray levels Explanation

Explanation

d: A rotation of the histogram Explanation

Explanation

5. A negative transformation for an 8-bit image is given by

s = 255-r

. If a pixel has value

r=40

, what is its transformed value?

40

Explanation

215

Explanation

255

Explanation

295

Explanation

6. An image has a histogram concentrated in a narrow range of gray levels. What does this observation directly indicate?

a: The pixels occupy only a limited range of intensities Explanation

Explanation

b: The image must have exactly one object Explanation

Explanation

c: The image must have been rotated Explanation

Explanation

d: The image contains every possible gray level equally often Explanation

Explanation

7. An image and its

180^\circ

rotated version are compared using their histograms. Why are the histograms the same?

a: Rotation changes every gray level by the same amount Explanation

Explanation

b: Rotation changes the number of pixels in the image Explanation

Explanation

c: Rotation changes spatial locations but preserves the gray-level values and their frequencies Explanation

Explanation

d: Rotation converts the histogram into a negative image Explanation

Explanation

8. A histogram has two different images represented by the same gray-level frequencies but with different spatial arrangements. What can the histogram alone distinguish?

a: The exact location of each pixel Explanation

Explanation

b: The spatial arrangement of objects Explanation

Explanation

c: The gray-level distribution, but not the spatial arrangement Explanation

Explanation

d: The orientation of every object Explanation

Explanation

9. For a

b

-bit grayscale image, which expression gives the number of possible gray levels?

b^2

Explanation

2b

Explanation

2^{b-1}

Explanation

2^b

Explanation

Image Histogram