Pre-trained model based conversion from day to night is producing not so good results for high resolution images.

[ankur-chr]

@sauradip I tried to use the pretrained model. However, the day to night time conversion is producing not so good results. Sometimes the image is too dark (with no added lighting effect: ex car light, street light), or at times the image produced is just a little darker version of the real day time image. Is there a way to fix this?

I used the pytorch colab implementation link from here (https://github.com/junyanz/pytorch-CycleGAN-and-pix2pix) to test this. (link found via the cyclegan link in the readme). Tested this with and without '--preprocess none' option, as the day images are high resolution 1024 x 2048 images. If the preprocess none option is not used, then the generated images have better effect of car lights, etc, however, they are much smaller in resolution (256x256), which is not what I need (required output resolution is 1024 x 2048).

Also tried using the gamma correction code as suggested. But getting the following error in that:
error: OpenCV(4.1.2) /io/opencv/modules/core/src/matrix.cpp:406: error: (-215:Assertion failed) m.dims >= 2 in function 'Mat'

Could you please share some pointers?