anyone having cam issues with galaxy s4???

[diamondlr1]

I am having a problem with my camera on my galaxy s4 (back camera, front camera works fine). When I open the camera app if I don't get a complete black screen (which is 90% of the time) the camera shows purple bars through the screen like it is malfunctioning then freezes and says that the camera failed. I have gone to a sprint repair store and they tried to troubleshoot it by resetting my phone and the camera worked fine for a little bit but then went back to the same as described above. Has anyone had the same issue with their phone??? any suggestions on how to fix my phone would be greatly appreciated...