Hardware Implementation of an Automatic Rendering Tone Mapping Algorithm for a Wide Dynamic Range Display

Abstract

Tone mapping algorithms are used to adapt captured wide dynamic range (WDR) scenes to the limited dynamic range of available display devices. Although there are several tone mapping algorithms available, most of them require manual tuning of their rendering parameters. In addition, the high complexities of some of these algorithms make it difficult to implement efficient real-time hardware systems. In this work, a real-time hardware implementation of an exponent-based tone mapping algorithm is presented. The algorithm performs a mixture of both global and local compression on colored WDR images. An automatic parameter selector has been proposed for the tone mapping algorithm in order to achieve good tone-mapped images without manual reconfiguration of the algorithm for each WDR image. Both algorithms are described in Verilog and synthesized for a field programmable gate array (FPGA). The hardware architecture employs a combination of parallelism and system pipelining, so as to achieve a high performance in power consumption, hardware resources usage and processing speed. Results show that the hardware architecture produces images of good visual quality that can be compared to software-based tone mapping algorithms. High peak signal-to-noise ratio (PSNR) and structural similarity (SSIM) scores were obtained when the results were compared with output images obtained from software simulations using MATLAB.

Real-time Tone Mapping: A State of the Art Report

“…On the other hand, due to floating-point arithmetic can save a huge range of luminance with small bit depth. Yadid-Pecht Orly et al in [21,38] proposed a FPGA implementation of tone mapping algorithm for HDR images with floating-point arithmetic. Different researches implemented different TMO of HDR images with different data type on different hardware.…”

Local tone mapping algorithm and hardware implementation

“…The pixel status module keeps track of the row and column number of the current input pixel and outputs the row and column number pair to block div module where decisions are made to keep the maximum and minimum pixel values of each block. The values are then passed to and stored in the regfile module for the use of the next frame because when operating in real time, we reasonably assume without any exaggeration that there is very little variation between successive image frames [5, 8]. Hence, image statistics (like minimum and maximum) acquired from one frame can be used to process the subsequent frame.…”

“…Local tone mapping takes pixel neighbour statistics into account, and they can produce images with more contrast and brightness than global tone mapping algorithms. However, many local tone mapping algorithms are computationally expensive and require a significant amount of hardware resources for implementation [5][6][7][8]. In this Letter, we first propose a novel local tone mapping algorithm which processes the WDR image in a pixel-by-pixel manner, and then we present the hardware implementation of the algorithm.…”

A Biological Retina Inspired Tone Mapping Processor for High-Speed and Energy-Efficient Image Enhancement

“…This work achieves real-time processing with high resource utilization. Reference [ 9 ] proposed a tone mapping processor using exponent-based tone mapping algorithm [ 10 ]. It achieves real-time processing with high image quality, however, it is prone to halos that significantly affect the visual effect.…”