SYSTEM FOR ROTATING IMAGE BY USING ROTATING DEVICE

PROBLEM TO BE SOLVED: To make it possible to efficiently rotate an image without degrading the system performance and without requiring an intricate hardware by using a prefetch buffer and an off screen memory in order to rotate the image. SOLUTION: The prefetch buffer 380 and the off screen memory 390 are used in order to rotate the image. The display device 370 has the prefetch buffer 380 capable of periodically detecting whether the image has been updated or not. If the image has been updated, the prefetch buffer 380 is capable of fetching the pixel data stored in a display memory 340 with continuous address sequence. After the prefetch buffer 380 completely arrays the pixel data, the prefetch buffer 380 delivers the results to the off screen memory 390. The off screen memory 390 sends the pixel data to a CRTC 350 in order to display the data on a CRT 360 according to the converted continuous address sequence.