Python Coding challenge - Day 679| What is the output of the following Python Code?

 

Code Explanation:

1. Import Libraries

import cv2

import numpy as np

cv2 → OpenCV library, mainly for image processing.

numpy → Used here to create the image as an array of numbers.

2. Create a Blank Image

img = np.zeros((100,100,3), dtype=np.uint8)

np.zeros((100,100,3)) → makes an array of shape (100,100,3) filled with zeros.

100,100 → height and width of the image.

3 → 3 color channels (B, G, R).

dtype=np.uint8 → pixel values range from 0–255 (standard for images).

Since all values are 0, this creates a black image of size 100×100.

3. Draw a Line

cv2.line(img, (0,0), (99,99), (255,0,0), 1)

cv2.line(image, start_point, end_point, color, thickness)

image = img

start_point = (0,0) → top-left corner.

end_point = (99,99) → bottom-right corner.

color = (255,0,0) → Blue in BGR format.

thickness = 1 → line width = 1 pixel.

This draws a blue diagonal line from the top-left to bottom-right.

4. Access Pixel Value

print(img[0,0])

img[y,x] → gets the pixel at row y, column x.

img[0,0] → pixel at top-left corner.

Since we drew a line that passes through (0,0), this pixel is part of the line.

The line color = (255,0,0) (Blue).

Final Output

[255   0   0]

This means:

Blue = 255

Green = 0

Red = 0

So the pixel is pure blue.

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