Solution to https://stackoverflow.com/questions/69319883/convert-a-csv-file-to-image-for-opencv

import numpy as np
import cv2


print('Loading CSV...')
raw = np.loadtxt('HEA_515_01.csv', delimiter=';', skiprows=1)
print('Loaded %d rows.' % len(raw))

# Split the array for convenience...
x = raw[:,0]
y = raw[:,1]
value = raw[:,2]

min_x, max_x = x.min(), x.max()
min_y, max_y = y.min(), y.max()
min_val, max_val = value.min(), value.max()

# Determine output image size....
count_x = len(np.unique(x))
count_y = len(np.unique(y))

# Calculate accurate step sizes
step_x = (max_x - min_x) / (count_x - 1)
step_y = (max_y - min_y) / (count_y - 1)

# Remap x and y to pixel coordinates
x = np.int32(np.rint((x - min_x) / step_x))
y = np.int32(np.rint((y - min_y) / step_y))

# Normalize values to range [0.0, 1.0]
value = (value - min_val) / max_val

# Create destination array...
result = np.full((count_y, count_x), np.nan)

# Assign the values...
result[y,x] = value

assert(np.count_nonzero(np.isnan(result)) == 0)

cv2.imwrite('output.png', np.uint8(result * 255))