A $4\times 4$ digital image has pixel intensities ($U$) as shown in the figure. The number of pixels with $U\le 4$ is:

0	1	0	2
4	7	3	3
5	5	4	4
6	7	3	2

Pixel Intensity Analysis for Digital Image

The problem asks us to count the number of pixels in a given $4\times 4$ digital image whose intensity value ($U$) is less than or equal to 4. The pixel intensities are provided as:

0, 1, 0, 2, 4, 7, 3, 3, 5, 5, 4, 4, 6, 7, 3, 2

Identify Pixels Satisfying the Condition

We need to find pixels where the intensity '$U\le 4$ '. Let's examine each pixel value:

- 0: $0\le 4$ (Yes)
- 1: $1\le 4$ (Yes)
- 0: $0\le 4$ (Yes)
- 2: $2\le 4$ (Yes)
- 4: $4\le 4$ (Yes)
- 7: $7\le 4$ (No)
- 3: $3\le 4$ (Yes)
- 3: $3\le 4$ (Yes)
- 5: $5\le 4$ (No)
- 5: $5\le 4$ (No)
- 4: $4\le 4$ (Yes)
- 4: $4\le 4$ (Yes)
- 6: $6\le 4$ (No)
- 7: $7\le 4$ (No)
- 3: $3\le 4$ (Yes)
- 2: $2\le 4$ (Yes)

Calculate Total Count

Count the number of pixels identified as satisfying the condition '$U\le 4$ '.

The pixels satisfying the condition are: 0, 1, 0, 2, 4, 3, 3, 4, 4, 3, 2.

Total count = 11.