OK, I think I found the problem.

First problem is edge detection is not right. Because I use vulkan which default coordinate system is y flip. So I need `#define SMAA_FLIP_Y 0` to make SMAA rightly processing.

Second problem is blend weight not clear. It is because I use UNORM color format rather than sRGB format. Use later will make blend output color is clear. Well this is not influence the result output image I thinking.