OpenCV imwrite saving complete black jpeg

Question

I have done some pre processing for dft , and i am trying to save this image by imwrite.

My cropped image has this information

output.type()                


        

Answer 1

A Python solution for those who come here from Google

import numpy as np
import cv2

frame_normed = 255 * (frame - frame.min()) / (frame.max() - frame.min())
frame_normed = np.array(frame_normed, np.int)

cv2.imwrite("path/to/out/file", frame_normed)