Solving Eq. (12) for the difference map d_m,n (Fig. 4 right panel), one obtains a solution for the offset values P. For comparison we show in the left panel the reconstructed difference map (which is basically a noise-free version of the input difference map). Via Eq. (14) one can easily compute a correction map (second panel) that can be subtracted from the original “dirty” map (see Fig. 4 third panel). The result is a cleaned data set (third panel), from which image artifacts are visually removed. The right panel shows the difference of the clean and cleaned map. Residual stripes appear, but they are suppressed by about an order of magnitude compared to the correction map (note the different intensity scale).