METHOD FOR GENERATING PSEUDO HALF TONE PICTURE DATA

摘要

PURPOSE:To improve the picture quality of a reduced picture by selecting a pseudo half tone slice corresponding to a reduced ratio among plural pseudo half tone slices to reduce the difference between a pseudo half tone picture before reducing and a reduced half tone picture after interleaving. CONSTITUTION:The pseudo half tone slice level data is stored in a memory 15 and the pseudo half tone slice is considered to be close to the pseudo half tone picture before reducing when the slice is interleaved and reduced by 1/2. Plural sets of the slice level data are stored in advance in a fixed memory such as an ROM and grouped into addresses by using signals S1, S2 designating the reduced ratio easily. The circuit in the figure is synchronized by using a horizontal clock T1 and a vertical clock T2. The horizontal clock T1 and the vertical clock T2 are generated easily by a pulse oscillator. The address information by the signals S1, S2 designating the reduced ratio is generated by an operating switch or the like.