how to convert output gray image to rgb?

[twinsyssy1018]

hi ,thanks for your sharing. could you tell me how to convert the output gray image to color ? thank you very much.

[seunghwanyoo]

Hi, thanks for your interest.
Both input and output images are of RGB format. But it converts RGB into YCbCr and the algorithm is applied only to Y channel. For Cb and Cr channels, bicubic interpolation is used instead. At the end, Y channel and CbCr channels in high-resolution are combined and converted into RGB back (convert_y2rgb()).