Samsung S4 Camera Problem

Hi guys, i have posted a topic about this before, but didn’t get much joy, so posting a similar one with a bit more information…
The camera on my S4 is poor when using the camera function, but when using it for snapchat it seems fine….
I have tried changing settings in the camera and nothing seems to help, the pictures are grainy, of low quality and have lines down them sometimes…. this is normally in low light situations, but sometimes happens during the daytime in light(ish) situations.
Can anyone help me? here is a picture to show you the difference between camera function and snapchat camera.
Answer #1
Something is wrong with yours. I tested mine out just now in well lit area and low light. I have not touched the 13 megapixel in these pictures. Its using 8 megapixel. Auto focus and auto picture mode.
Well Lit (Left) Low Light w/flash (Right) Low Light No flash (Bottom)

Answer #2
Bug with the app most likely, send a ticket to the devs
Answer #3
Upgrade firmware.
Answer #4
download lg camera its the best app for taking videos and photos