about dict in Seg fuction

[whyandbecause]

Hi, your reproduction is very helpful to me, But I have a question, where does the definition of dict in Seg() come from, or what is the theory-based? thank you.
dict = {0: 0, 1: 1, 2: 8, 3: 16, 4: 9, 5: 2, 6: 3, 7: 10, 8: 17,
9: 24, 10: 32, 11: 25, 12: 18, 13: 11, 14: 4, 15: 5, 16: 12,
17: 19, 18: 26, 19: 33, 20: 40, 21: 48, 22: 41, 23: 34, 24: 27,
25: 20, 26: 13, 27: 6, 28: 7, 29: 14, 30: 21, 31: 28, 32: 35,
33: 42, 34: 49, 35: 56, 36: 57, 37: 50, 38: 43, 39: 36, 40: 29,
41: 22, 42: 15, 43: 23, 44: 30, 45: 37, 46: 44, 47: 51, 48: 58,
49: 59, 50: 52, 51: 45, 52: 38, 53: 31, 54: 39, 55: 46, 56: 53,
57: 60, 58: 61, 59: 54, 60: 47, 61: 55, 62: 62, 63: 63}

[Moushumi9medhi]

The dict in seg refers to the indices of DCT coefficients when encoded in the zigzag manner.
But if this is so, I think there is an issue with the following lines of code:

high = torch.cat([feat_y[:, 32:, :, :], feat_Cb[:, 32:, :, :], feat_Cr[:, 32:, :, :]], 1)
low = torch.cat([feat_y[:, :32, :, :], feat_Cb[:, :32, :, :], feat_Cr[:, :32, :, :]], 1) 

As in the above, the high and low frequency bands are simply extracted from the last 32 and the first 32 frequencies, which does not follow the zigzag pattern.

[whyandbecause]

The dict in seg refers to the indices of DCT coefficients when encoded in the zigzag manner. But if this is so, I think there is an issue with the following lines of code:

high = torch.cat([feat_y[:, 32:, :, :], feat_Cb[:, 32:, :, :], feat_Cr[:, 32:, :, :]], 1)
low = torch.cat([feat_y[:, :32, :, :], feat_Cb[:, :32, :, :], feat_Cr[:, :32, :, :]], 1) 

As in the above, the high and low frequency bands are simply extracted from the last 32 and the first 32 frequencies, which does not follow the zigzag pattern.

Hi, thank you for your answer. I think i have got the meaning of this dict. About 'does not follow the zigzag pattern', my simple understand is that the 288-290 lines have made the high frequency extraction through self.seg in a zigzag manner，so we can simply split the channels to get high/low frequency. I hope it's useful for you. Thank you.