| 摘要 |
<p>PURPOSE:To perform coordinate transformation by a small number of times of addition by using a system that combines plural component angles to a specified rotation angel and using one of -90 deg., 90 deg., 180 deg. for one of them when rotating a picture. CONSTITUTION:When a rotation angle is set to a rotation angle register 1, the content is analyzed with respect to the fact that the rotation angle is constituted of component angle by which combination through a rotation controlling circuit 2. When the consequent rotation angle is smaller than -45 deg. or larger than 45 deg., one of -90 deg., 90 deg., 180 deg. is selected as one of them. The rotation angle of n-th time is sent to a selected circuit 3, and at the same time, a read/write controlling line between rotation memories 11 and 12 is controlled. When all rotations are completed, it is reported to a controlling section, and if not, the next rotation angle is outputted to the circuit 3. By using a system in which rotation of plural component angles is read and written alternately between rotation memories 11, 12 coordinate transformation can be made by a small number of times of addition.</p> |
