Like Hodgman said, My initial setting was 1/2 texel size off on DX9.
After fixing the issue the textures still renders the old jaggy pattern
Initially I noticed some difference in the image when rendering to texture vs normal rendering in the case of DX9.
Now, both look the same. I am assuming the 1/2 texel problem is accounted for.
I used this article to understand the color space stuff
Tried to use the color space as in the Fxaa_3.11 header. But still no dice.
Reattaching updated shaders.
lol... Maybe I should go for SMAA
Fxaa3 (lower quality 0.62 ms) vs SMAA Tx2 (higher quality 1.32 ms)
Hard to decide