Accelerating rotation of high-resolution images

Real-time image rotation is an essential operation in many application areas such as image processing, computer graphics and pattern recognition. Existing architectures that rely on CORDIC computations for trigonometric operations cause a severe bottleneck in high-throughput applications, especially where high-resolution images are involved. A novel hierarchical method that exploits the symmetrical characteristics of the image to accelerate the rotation of high-resolution images is presented. Investigations based on a 512times512 image show that the proposed method yields a speedup of ~20times for a mere 3% increase in area cost when compared with existing techniques. Moreover, the effect of hierarchy on the computational efficiency has been evaluated to provide for area-time flexibility. The proposed technique is highly scalable and significant performance gains are evident for very high-resolution images