No, it won't. The reason why it makes those phones take worse pictures is because the manufacturer has their own closed source libraries for processing images and autofocus, so custom ROMs are forced to use the (usually worse) AOSP camera libraries. The Nexus 4 is based off of AOSP, so stock already has the AOSP camera libraries.
PHONES: iPhone 3GS (Retired, Jailbroken, iDroid, overclocked to 800MHz) -> Motorola Atrix 4G (Shattered, CM10, Faux kernel @ 1.45 ghz overclocked) -> Google/LG Nexus 4 (Primary Phone, PSX v2), Franco kernel) + Motorola Atrix HD (Secondary Phone (For when the battery dies on the Nexus 4), PSX v1)
TABLETS: Sony Tablet S (Retired, rooted 4.0.3), Surface Pro 2 128GB (Current, W8.1)