Castlevania The Dracula X Chronicles US

[LunaMoo]

It's not a bug, nor issue with your settings, postprocessing shaders are applied on whole output that's it - if they don't work on some elements it just means it's effect was designed to apply only on some elements like ie edges or certain color patterns.

In general games which re-use content from older consoles(which this one I belive does) or either due to budget or design choice use "pixel art"/low quality content are the worst case scenario for most post processing shaders.

Dunno what you ment by "bilinear filtering not working" as from screenshots posted earlier in this thread game is very blurry ~ most likely due to stretching ps1 res into psp one with that particular filtering.