Efficient implementation of a cubic-convolution based image scaling engine
In video applications, real-time image scaling techniques are often required. In this paper, an efficient implementation of a scaling engine based on 4×4 cubic convolution is proposed. The cubic convolution has a better performance than other traditional interpolation kernels and can also be realized on hardware. The engine is designed to perform arbitrary scaling ratios with an image resolution smaller than 2560×1920 pixels and can scale up or down, in horizontal or vertical direction. It is composed of four functional units and five line buffers, which makes it more competitive than conventional architectures. A strict fixed-point strategy is applied to minimize the quantization errors of hardware realization. Experimental results show that the engine provides a better image quality and a comparatively lower hardware cost than reference implementations.
Key wordsCubic-convolution Hardware implementation Interpolation Engine
CLC numberTN79+1 TP752
- Farrow, C.W., 1988. A Continuously Variable Digital Delay Element. IEEE Int. Symp. on Circuits and Systems, 3:2641–2645. [doi:10.1109/ISCAS.1988.15483]Google Scholar
- Feng, T., Xie, W.L., Yang, L.X., 2001. An Architecture and Implementation of Image Scaling Conversion. 4th Int. Conf. on ASIC, p.409–410. [doi:10.1109/ICASIC.2001.982587]Google Scholar
- Lin, C.C., Sheu, M.H., Chiang, H.K., Liaw, C., Wu, Z.C., 2008. The Efficient VLSI Design of BI-CUBIC Convolution Interpolation for Digital Image Processing. IEEE Int. Symp. on Circuits and Systems, p.480–483. [doi:10.1109/ISCAS.2008.4541459]Google Scholar
- Nuno-Maganda, M.A., Arias-Estrada, M.O., 2006. Real-Time FPGA-Based Architecture for Bicubic Interpolation: an Application for Digital Image Scaling. Int. Conf. on Reconfigurable Computing and FPGAs, p.1–8. [doi:10.1109/RECONFIG.2005.34]Google Scholar
- Sheikh, H.R., Wang, Z., Cormack, L., Bovik, A.C., 2010. LIVE Image Quality Assessment Database Release 2. Available from http://live.ece.utexas.edu/research/quality/subjective.htm [Accessed on Oct. 18, 2010].
- Shi, H.J., Ward, R., 2002. Canny Edge Based Image Expansion. IEEE Int. Symp. on Circuits and Systems, 1:785–788. [doi:10.1109/ISCAS.2002.1009958]Google Scholar