I can't tell what is signal and what is noise from that profile. Can you post the entire image? Like Jan said, it depends on what the image looks like. There are tons of filters you could use from simple linear filters like a moving box filter, to the non-linear median filter, to more complicated filters like Knn, sigma, to even more complicated (and better) filters like BM3D,K-SVD, K-LLD, non-local means, UINTA, ets.
It depends on what the wanted result is. If you want to smooth the data extremely, usemean. A moving average filter is possible also, or a highpass filter, a Savitzki-Golay-filter or a mean over chunks of the data.