import numpy as np
import random
import cv2
[docs]def generate_random_pattern_img(width: int, height: int, n_points: int) -> np.ndarray:
"""Generate transparent image with random pattern.
:param width: width of image to be generated.
:param height: height of image to be generated.
:param n_points: number of white points uniformly placed on image.
"""
pattern_img = np.zeros((height, width, 4), dtype=np.uint8)
m_width = int(width // np.sqrt(n_points))
m_height = int(height // np.sqrt(n_points))
for i in range(width // m_width):
for j in range(height // m_height):
x_idx = random.randint(i * m_width, (i + 1) * m_width - 1)
y_idx = random.randint(j * m_height, (j + 1) * m_height - 1)
pattern_img = cv2.circle(pattern_img, (x_idx, y_idx), 1, (255, 255, 255, 255), -1)
return pattern_img