| 摘要 |
PURPOSE:To precisely vary magnification with an optional scale-factor by adjusting the frequency of a writing clock for input data so as to satisfy a prescribed condition. CONSTITUTION:In a method for mainly scanning picture elements in an original picture, converting the input data into a time-sequential binary electric signal and processing the converted input data to form variable magnification data, a CPU 1 executes operation based on an formula, encodes the calculated result and writes the encoded result in a RAM 4. The contents of the RAM 4 are successively read out through a CPU 3 and an address counter 8, the read contents are parallel/serial converted by a shift register 5 to which a reference pulse is supplied to generate a writing pulse of required frequency. Data are written in a picture memory of which contents are read out by a fixed frequency clock by a writing clock whose frequency is adjusted to a required band so as to precisely execute the variable magnification for a picture with an optional scale-factor. In the formula, (a) is an integer, (m) is magnification fBS is the reference frequency of a writing clock, and fRD is the frequency of a reading clock. When a calculating value is a decimal value, the value is rounded to the 1st decimal place. |
