Real time Thermogram enhancement by FPGA-based contrast stretching

Abstract

Image enhancement is a challenging problem in the world of digital technology. Currently, producers of video cameras, are providing devices working with increasingly higher frequencies and resolutions of acquired video frames. However, that creates a need of development of methods used in image enhancement. Furthermore, real time processing of a significant amount of data require utilization of parallel processing. The paper presents the results of research on the problem of real time histogram stretching. Proposed solution utilizes parallel processing, supported by FPGA (Field Programmable Gate Array). The problem of histogram stretching is closely associated with thermal imaging, in which, in most of the cases, the range of measured infrared radiation, in the observed scene, is generally narrow, in relation to total possible range of radiation measured by IRFPA (Infrared Focal Plane Array), which results in narrow histogram and thus low contrast of the acquired image. The proposed solution can be used in every branch of contemporary industry, wherever video cameras are used. Real time operating hardware implementation, eliminates a need of further post-processing, and may be considered as useful and eligible in many modern applications.