Method for recording quasi half-tone pictures and apparatus for converting the tonal data of picture elements

摘要

In the method for binary recording of pictures in which a picture is reproduced by individual points having the colour value "full" or the colour value "zero", extensive fault calculations and considerations are in some cases required. The required fault calculations reduce the processing speed for the picture signals. …??To avoid fault considerations, provision is made to decide in each case by means of the sum of the tonal values of a few sampling points whether a recording point is to be printed to reproduce these sampling points. For this purpose, the sampling points just investigated are combined in an input switching network (34) to form groups for which an arithmetic processor (40) determines the sum of the tonal values. The arithmetic processor (40) outputs a signal when the sum of the tonal values exceeds a particular amount. When the signal is present, the recording point to be printed is determined in an output switching network (44). This method is progressively carried out for ever increasing areas of the original, that is to say sets of sampling points. …IMAGE…