An image signal processing system DPCM encodes the signal, then Huffman and run length encodes (112) the signal to produce variable length code words, which are then tightly packed without gaps for efficient transmission without loss of any data. The tightly packing apparatus has a barrel shifted (138) with its shift modulus controlled by an accumulator (140) receiving code word length information. An OR gate (144) is connected to the shifter, while a register (146) is connected to the gate. Apparatus for processing a tightly packed and decorrelated digital signal has a barrel shifted (238) and accumulator (240) for unpacking, a Huffman and run length decoder (212), and an inverse DCPM decoder (200).
Non-destructive lossless image coder.