A real-time implementation of gradient domain high dynamic range compression using a local Poisson solver

• Published in: Journal of real-time image processing Vol. 8; no. 2; pp. 153 - 167
• Main Authors: Vytla, Lavanya, Hassan, Firas, Carletta, Joan E.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer-Verlag 01.06.2013; Springer; Springer Nature B.V
• Subjects: Algorithms; Applied sciences; Artificial intelligence; Boundary conditions; Computer Graphics; Computer Science; Computer science; control theory; systems; Domains; Dynamic range; Electronics; Exact sciences and technology; Field programmable gate arrays; Fourier transforms; Frames per second; Hardware; Image compression; Image manipulation; Image Processing and Computer Vision; Image quality; Image reconstruction; Integrated circuits; Integrated circuits by function (including memories and processors); Methods; Multimedia Information Systems; Original Research Paper; Pattern Recognition; Pattern recognition. Digital image processing. Computational geometry; Poisson equation; Real time; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal,Image and Speech Processing; Solvers; Tone mapping operator; Poisson equation; Embedded hardware; Gradient domain dynamic range compression; Real time; Process dynamics; Hardware description languages; Image processing; Video signal; Video technique; Test standard; Field programmable gate array; Buffer system; Boundary condition; Color image; Depth of field; High Dynamic Range imaging; Color reproduction; Time domain method; VHDL language; Pixel
• ISSN: 1861-8200; 1861-8219
• DOI: 10.1007/s11554-011-0198-5

This paper presents a real-time hardware implementation of a gradient domain dynamic range compression algorithm for high dynamic range (HDR) images. This technique works by calculating the gradients of the HDR image, manipulating those gradients, and reconstructing an output low dynamic range image that corresponds to the manipulated gradients. Reconstruction involves solving the Poisson equation. We propose a Poisson solver that utilizes only local information around each pixel along with special boundary conditions, and requires a small and fixed amount of hardware for any image size, with no need to buffer the entire image. The hardware implementation is described in VHDL and synthesized for a field programmable gate array (FPGA) device. The maximum operating frequency achieved is fast enough to process high dynamic range videos with one megapixel per frame at a rate of about 100 frames per second. The hardware is tested on standard HDR images from the Debevec library. The output images produced have good visual quality.