a) Frame of the PACS imaging camera in the blue band. The darker and brighter isolated pixels are bad pixels. There is one complete bad line (at the bottom of the last matrix, ordered from the left to the right and from the bottom to the top). The observable structure is mainly the offset. Discontinuities in the offset correspond to the borders of the matrices of bolometers. There are physical gaps between matrices, as well as rotation and distortion. The matrix used in the transparent mode is the sixth one. b) The same frame with the offset removed. The brighter isolated pixels are glitches. c) The same frame after Hadamard transform. The offsets have not been removed.