Multi-scale camera projection matrices

[HencyChen]

Hi @JeffWang987

Thanks for the great work. There's a little confusion about the data preprocessing in dtu_yao4.py

Around Line 220, there are four different scales of corresponded camera intrinsic parameter. I aware MVSTER train the model in a multi-scale fasion, and the resolution of transformer outputs are as follows:

Stage 1: H/8 x W/8
Stage 2: H/4 x W/4
Stage 3: H/2 x W/2
Stage 4: H x W

So I expect the intrinsic of each stage will be /8, /4, /2, /1 sequentially. However, I find out in the code stage1 is /2, stage2 does nothing, stage3 is *2 and stage4 is *4 instead.

I'm wondering if there's something I misunderstand? Hope for a hint from you, thanks again for the great work!