| 摘要 |
PURPOSE:To increase the number of gradations without varying picture elements in size, by using a threshold pattern which is variable in the correspondence ratio of the picture elements and threshold pattern, when obtaining a binary- coded picture signal of a shade picture by using the threshold pattern. CONSTITUTION:WHen shade picture element are to be converted into a binary signal, four matrix elements (A) of a dot matrix threshold pattern are made to correspond to one picture element (B) of a shade picture signal. Consequently, the number of elements of an output equipment is only four times as many as the number of picture elements, i.e., (number of picture elements)X(number of gradations)X1/4. Further, it is unnecessary to average a picture element signal, so fidelity to an original picture is improved. |
