High-dynamic-range infrared image enhancement and hardware design

A new technique for the display of high-dynamic-range infrared images is presented in this paper, which reduces the dynamic range while preserving details. It is based on a two-scale decomposition of the image into a base layer and a detail layer. The base layer is obtained using an edge-preserving filter called the bilateral filter. We discuss the different characteristics between Gaussian filter and bilateral filter in filtering noise and edges. Then we present the technique of histogram projection based on the information of histogram. The proposed design is a combination of bilateral filter and histogram projection. And that is suitable for FPGA to map the 14-bit infrared image data to 8-bit values for display. This kind of technique has considered infrared image characteristic and vision characteristic of the human eye synthetically, and guarantees real-time character of image process, at the same time, also give consideration to the advantage of the FPGA design.