Understanding Mosaic Artifacts and “Hot” Regions Mosaic artifacts in 4K sensors commonly refer to two related phenomena. First is the color mosaic pattern produced by the color filter array (CFA), typically a Bayer pattern, which must be demosaiced into full-color images; improper demosaicing or insufficient per-pixel calibration can create zippering, color fringing, or blocky textures at fine detail levels. Second is structural or algorithmic mosaicing: visible block artifacts arising from compression, pixel-binning mismatches, or subsampling stages in the capture pipeline.