Method and arrangement for reducing the bandwidth and/or time required

Abstract

An image is scanned and dither processed in picture element groups of predetermined size, each corresponding to a group of cells of a remotely located display panel. As each picture element group is scanned, the pattern represented by the corresponding dithered image bits is compared to a dictionary of patterns stored in a first memory. If the pattern is not among those then in the memory, it is assigned an associated code word and is entered into the memory. In addition, both the pattern and its code word are transmitted to the remote location. They are there stored in a second memory, and individual cells of the cell group corresponding to the scanned picture elements are energized in accordance with the pattern. If, on the other hand, a scanned pattern is the same as one already stored in the first memory, only the code word associated with that pattern is transmitted to the remote location. The code word is used at the remote location to retrieve the associated pattern from the second memory when it is displayed at the corresponding cell group of the display panel.