When "GPU acceleration of video processing" is enabled in the Vegas Pro video preferences, the anti-aliased edges of imported Photoshop layers are paler than they should be.
The easiest way to demonstrate is with an example. Here is a zip file that contains a very simple VP10 project and associated 2-layer Photoshop file. The lower layer is a 320x240 grey rectangle. The upper layer is a centered 160x120 rectangle. The layers are added across tracks in the Vegas project. I have set the width and height of the project to 317x237 to force the edges of the smaller rectangle to not line up with pixel edges in the Vegas project so that they get anti-aliased by Vegas. With GPU acceleration on in VP12 or VP13 these anti-aliased edges appear paler than they should:
It seems to me that the GPU-anti-aliasing code is doing some unwanted "shaping" of the edges, increasing the luminance before fading out, a bit like the ringing created by sharpening. In the majority of cases of Photoshop import I would say this is unwanted.
If GPU acceleration is turned off, or in VP10, the whole area remains uniform grey, as it should.
I have tested this in VP12 and VP13, using either my Nvidia GTX 580 or my AMD HD 6970 for GPU acceleration.
Please can someone else verify this behaviour before I submit a bug report?