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

imwrite prints on a 0 to 255 scale, but your image is in a 0 to 1 scale. To scale up, use this line:

image.convertTo(image, CV_8UC3, 255.0);