| 摘要 |
PURPOSE:To increase the picture converting speed and to improve the flexibility against the change of the conversion algorithm, by using a read-only memory ROM, etc. for picture conversion. CONSTITUTION:The coordinates (X, Y) of a point (b) and conversion magnification ratios alpha and beta of a picture B obtained after conversion are supplied to ROMs 1-3. The ROM 1 delivers the (x) coordinates xk of a reference picture element akl, and the ROM 2 delivers the (y) coordinates yl of the element akl. While the ROM 3 delivers a logical arithmetic mode g5. Then both coordinates xk and yl are supplied to a memory 4 to deliver a picture element ak(l+1) shifted in the direction (y) by a step, a picture element a(k+1)l shifted in the direction (x) by a step and a picture element a(k+1)(l+1) shifted in both directions (x) and (y) by a step respectively. These picture elements are stored in registers 5-1-5-4 respectively. When four reference picture elements are obtained, a gate circuit 6 at the preceding stage of a ROM 7 is opened to supply the reference picture element value and the logical arithmetic mode to the ROM 7. Then the ROM 7 delivers the value of a converted picture element (b). |
