Virtual Labs

Point Operations

1. In a point operation, if the input pixel value at location

(x,y)

p

, how is the corresponding output pixel value

q

determined?

q = T(p)

Explanation

q = T(x,y)

Explanation

q = T(p,x,y)

using neighbouring pixels Explanation

Explanation

q = p + x + y

Explanation

2. Which parameter pair in the linear transformation

q = sp + o

is responsible for changing the contrast and brightness of an image?

p

and

q

Explanation

s

and

o

Explanation

x

and

y

Explanation

a

and

b

only Explanation

Explanation

3. Which of the following is a nonlinear transformation discussed in the Point Operations experiment?

q = sp + o

Explanation

q = p

Explanation

q = c \log(1+p)

Explanation

q = p + o

Explanation

4. A linear transformation is given by

q = 2p + 10

. What is the output value for an input pixel with

p = 50

, before any range adjustment?

60

Explanation

90

Explanation

100

Explanation

110

Explanation

5. An image contains many low-intensity pixels, and the goal is to expand their range while compressing higher-intensity values. Which transformation is most appropriate according to the experiment?

a: Logarithmic transformation Explanation

Explanation

b: Window function Explanation

Explanation

c: Clipping transformation Explanation

Explanation

d: Neighbourhood averaging Explanation

Explanation

6. For the clipping transformation, suppose

a = 50

b = 200

, and the input pixel value is

p = 220

. What is the output value for the 8-bit grayscale case?

0

Explanation

50

Explanation

200

Explanation

255

Explanation

7. A window function is configured with an input range

a \leq p \leq b

. What happens to an input pixel value satisfying

p < a

p > b

a: It is mapped to

255

Explanation

b: It is mapped to

0

Explanation

c: It is multiplied by the input coordinate Explanation

Explanation

d: It is replaced by the value of a neighbouring pixel Explanation

Explanation

8. Consider two input pixels with values

p_1 = 40

and

p_2 = 180

. A window function preserves only the range

50 \leq p \leq 150

. Which statement correctly describes the outputs for these two pixels?

a: Both pixels are mapped to

255

Explanation

b: Both pixels are mapped to

0

Explanation

c: The first is mapped to

0

, while the second is processed within the selected range Explanation

Explanation

d: The first is processed within the selected range, while the second is mapped to

0

Explanation

9. A point transformation maps some input values outside the valid 8-bit grayscale range. Why is range adjustment important in this experiment?

a: It ensures that the transformed values can be represented within the valid grayscale range Explanation

Explanation

b: It makes every point operation depend on neighbouring pixels Explanation

Explanation

c: It guarantees that every output pixel has the same intensity Explanation

Explanation

d: It removes the transformation function from the processing step Explanation

Explanation