Switching system for image enhancement and analysis of fused thermal and RGBD data

Abstract

A number of methods have been developed in the past for color image enhancement, including retinex and color constancy algorithms. theory is based on psychophysical experiments using mondrian patterns. Recently, multi-scale retinex algorithms have been developed. They combine several Retinex outputs to produce a single output image which has both good dynamic range compression and color constancy, as well as good tonal rendition. Unfortunately, multi-scale retinex processing time is consuming. In this paper we present a new algorithm for color and thermal image enhancement. Additionally, an experimental prototype system for fusing the two data types with depth data to create a three-dimensional map of the datasets is presented. The image processing algorithm utilizes a combination of fourier domain and retinex algorithms. Different types of thermal and natural scene NASA images have been tested, along with other imagery. The primary advantages of the image processing algorithm are the reduced computational complexity and the contrast enhancement performance. Experimental results demonstrate that the algorithm works well with underexposed images. The algorithm also gives better contrast enhancement in most cases, thus bringing out the true colors in the image. It thus helps in achieving both color constancy and local contrast enhancement. We compare the presented method with enhancement based on NASA's Multi-scale Retinex. Statistically and quantitatively, we have shown that our technique indeed results in enhanced images, with our argument validated by conducting experiments on human observers. Additionally, the fusion of 2-dimensional (2D) thermal, 2D RGB, and 3-dimensional (3D) depth data (TRGBD) can be analyzed and researched for the purpose of extrapolating thermal conductance and other thermal properties within a scanned environment. This will allow for the determination of energy assessments regarding structural boundaries, the effectiveness of insulation, leakages of heat, water and refrigerant, and computing the true value of observed thermal losses/gains as they are related not only to thermal properties, but geometries as well. The data generated from this analysis can be used in many other domains and process evaluation fields such as medical, geological, architectural and others.