reflection padding

[baopmessi]

Thanks for your awesome work. I have a little question about the paper. In the paper mentioned:
"To prevent the texture code from encoding positional information, we apply reflection padding for the residual blocks, and then no padding for the conv blocks. ". Hope you will explain.

[taesungp]

For ideal disentanglement, the structure code should contain all information that is specific to a particular location. In contrast, the texture code should contain the overall distribution of texture. In other words, the texture code should capture the overall style or "feel" of the image. This means that the texture code should not make use of any positional information. For example, the texture code should not make use of the fact that there is a church at pixel (232, 130). To enforce this in our architectural design, we use reflection padding. Otherwise, if we use zero padding, the conv layers will learn to recognize image boundaries. From there it may be able to recognize the coordinates of each location by measuring how far it is from the boundary.

An alternative way to avoid the use of zero padding is by using no padding at all. While this should also work, the output size of conv layer without any padding is hard to compute. Especially, it's hard to compute the correspondence of locations before and after the conv layer. So we decided to use reflection padding for the residual blocks before producing the structure codes, which require explicit correspondence between the image pixels to each location of the structure codes.

For reference, the relevant lines of code are here and here

[baopmessi]

Great and clear answer. Thanks you so much. Sorry for my English.
I have a little confuse about Interactive user interface:

• Base on architecture. We can edit texture in global fashion. and edit structure code in region (local) . Is there any way to edit texture of specified region (local). ie: snow in a mountain and no snow in others mountain. Are you inject texture (style) code at corresponding locations in feature map.

Hope you will explain.