Abstract
This paper presents an FPGA implementation of a novel image enhancement algorithm, which compensates for the under-/over-exposed image regions, caused by the limited dynamic range of contemporary standard dynamic range image sensors. The algorithm, which is motivated by the attributes of the shunting center-surround cells of the human visual system, is implemented in Altera Stratix II GX: EP2SGX130GF1508C5 FPGA device. The proposed implementation, which is synthesized in an FPGA technology, employs reconfigurable pipeline, structured memory management, and data reuse in spatial operations, to render in real-time the huge amount of input data that the video signal comprises. It also avoids the use of computationally intensive operations, achieving the required specifications in terms of flexibility, timing, performance and visual quality. The proposed implementation allows real-time processing of color images with sizes up to 2.5 Mpixels, at frame rate of 25 fps. As a result, the architectural solution described in this work offers a low-cost implementation for automatic exposure correction in real-time video systems.
Similar content being viewed by others
References
Battiato, S., Castorina, A., Mancuso, M.: High dynamic range imaging for digital still camera: an overview. J. Electron. Imaging 12, 459–469 (2003). doi:10.1117/1.1580829
Benedetti, A.: Image convolution on FPGAs: the implementation of a multi-FPGA FIFO structure. EUROMICRO’98 1, 123–130 (1998)
Elad, M., Kimmel, R., Shaked, D., Keshet, R.: Reduced complexity retinex algorithm via the variational approach. J. Vis. Commun. Image Representation 14, 369–388 (2003)
Funt, B., Ciurea, F., McCann, J.: Retinex in Matlab. J. Electron. Imaging 13, 48–57 (2004). doi:10.1117/1.1636761
Goshtasby, A.: Fusion of multi-exposure images. Image Vis. Comput. 23, 611–618 (2005). doi:10.1016/j.imavis.2005.02.004
Hines, G.D., Rahman, Z., Jobson, D.J., Woodell, G.A.: DSP implementation of the Retinex image enhancement algorithm. In: Proceedings of the SPIE 5438: Visual Information Processing XIII, Orlando, USA, pp. 13–24 (2004)
Hines, G., Rahman, Z., Jobson, D.J., Woodell, G.A., Harrah, S.D.: Real-time enhanced vision system. In: Proceedings of the SPIE 5802: Enhanced and Synthetic Vision, Orlando, USA, pp. 127–134 (2005)
Jobson, D., Rahman, Z., Woodell, G.: Properties and performance of a center/surround Retinex. IEEE Trans. Image Process. 6, 451–462 (1997). doi:10.1109/83.557356
Jobson, D., Rahman, Z., Woodell, G.: A multi-scale Retinex for bridging the gap between color images and the human observation of scenes. IEEE Trans. Image Process. 6, 965–976 (1997). doi:10.1109/83.597272
Kimmel, R., Elad, M., Shaked, D., Keshet, R., Sobel, I.: A variational framework for Retinex. Int. J. Comput. Vis. 52, 7–23 (2003). doi:10.1023/A:1022314423998
Land, E.: The Retinex. Am. Sci. 2, 247–264 (1964)
Land, E.: An alternative technique for the computation of the designator in the Retinex theory of color vision. Proc. Natl. Acad. Sci. USA 83, 3078–3080 (1986). doi:10.1073/pnas.83.10.3078
Meylan, L.: Tone mapping for high dynamic range images. s.l.: EPFLThesis No. 3588
Meylan, L., Süsstrunk, S.: High dynamic range image rendering with a retinex-based adaptive filter. IEEE Trans. Image Process. 15, 2820–2830 (2006). doi:10.1109/TIP.2006.877312
Provenzi, E., Fierro, M., Rizzi, A., De Carli, L., Gadia, D., Marini, D.: Random spray Retinex: a new retinex implementation to investigate the local properties of the model. IEEE Trans. Image Process. 16, 162–171 (2007). doi:10.1109/TIP.2006.884946
Reinhard, E., Devlin, K.: Dynamic range reduction inspired by photoreceptor physiology. IEEE Trans. Vis. Comput. Graph. 11, 13–24 (2005). doi:10.1109/TVCG.2005.9
Sepora, S., Fanucci, L., Marsi, S., Ramponi, G.: Algorithmic and architectural design for real-time and power-efficient Retinex image/video processing. J. Real-Time Image Process. 1, 267–283 (2007). doi:10.1007/s11554-007-0027-z
Sobol, R.: Improving the Retinex algorithm for rendering wide dynamic range photographs. J. Electron. Imaging 13, 65–74 (2004). doi:10.1117/1.1636762
Vonikakis, V., Andreadis, I., Gasteratos, A.: Fast centre-surround contrast modification. IET Image Process. 2, 19–34 (2008). doi:10.1049/iet-ipr200712
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Iakovidou, C., Vonikakis, V. & Andreadis, I. FPGA implementation of a real-time biologically inspired image enhancement algorithm. J Real-Time Image Proc 3, 269–287 (2008). https://doi.org/10.1007/s11554-008-0090-0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11554-008-0090-0