Performance Optimization and FPGA Implementation of Real-Time Tone Mapping

This brief analyzes the performance of the hardware-based tone mapping operators for compression of high dynamic range images. The bottlenecks of a tone mapping system are determined and a high-performance field programmable gate array (FPGA) implementation of an operator is introduced. The operator utilizes polynomial mapping technique, adaptive to the pixel values; hence preserving high contrast areas. The technique is further optimized for the presented resource-efficient FPGA implementation. We show that the timing optimization does not reduce the image quality, by obtaining high peak signal-to-noise ratio of the resulting images. The timing comparison to the similar implementations shows 2.5 times increase in the achieved throughput, irrespective of the hardware platform

Multi-Camera Platform for Panoramic Real-Time HDR Video Construction and Rendering

High dynamic range (HDR) images are usually obtained by capturing several images of the scene at different exposures. Previous HDR video techniques adopted the same principle by stacking HDR frames in time domain. We designed a new multi-camera platform which is able to construct and render HDR panoramic video in real-time, with 1024 × 256 resolution and a frame rate of 25 fps. We exploit the overlapping fields-of-view between the cameras with different exposures to create an HDR radiance map. We propose a method for HDR frame reconstruction which merges the previous HDR imaging techniques with the algorithms for panorama reconstruction. The developed FPGA-based processing system is able to reconstruct the HDR frame using the proposed method and tone map the resulting image using a hardware-adapted global operator. The measured throughput of the system is 245 MB/s, which is, up to our knowledge, among the fastest HDR video processing systems