Showing papers on "Illumination problem published in 2010"

Illumination invariant face recognition: A survey of passive methods

Abstract: Face recognition under varying illumination is one of the challenging problems in real-time applications. Numerous methods have been developed by the research community to handle the problem. Existing surveys of methods are either too old or do not cover performance analysis of illumination invariant methods. This paper is more extensive than previous surveys and covers recently developed methods. The paper focuses on passive methods which solve the illumination problem by investigating the visible light images in which the face appearance has been altered by varying illumination. The methods are classified into four broad categories, namely (1) subspace-based statistical methods (2) illumination invariant representation methods, (3) model based methods, (4) other illumination handling methods. The other illumination handling category includes the methods which do not fall under first three categories. Performance analysis and discussion of methods and an evaluation of results is presented to determine the suitability and applicability of the method(s) for specific applications. It is observed from the survey of methods that illumination invariant representation based methods are better in terms of the number of training images required, the simplicity, computational complexity and robustness.

Survey on enhancement methods for non-uniform illumination image

Abstract: In order to solve the non-uniform illumination problem of digital images, which was caused by poor light environment or lighting disproportionation on object’s surface, this paper provided some common enhancement methods.They included gray transformation represented by histogram equalization, homomorphic filtering based on illumination-reflectance model, Retinex enhancement theory and gradient field method.Compared these methods’ effect,analysed their application scopes and gave the solution direction of the non-uniform illumination problem.

Box-and-Ellipse-Based ANFIS for Bridge Coating Assessment

Abstract: In the late 1990s, image processing was first applied to steel bridge coating assessment in the United States. Yet, there has not been any robust method that could solve nonuniform illumination problems to date. In this regard, this paper aims to develop an approach that handles nonuniform illumination in rust image recognition. The proposed approach also contributes to rust intensity recognition and process automation. This paper adopts the a∗ b∗ color configuration (of the L∗ a∗ b∗ color space) which is shown to be the best coordinate system for rust recognition by the proposed method. Different rust colors are regarded as relating to different degrees of rust intensity. Due to the difficulty of defining light rust colors, the adaptive-network-based fuzzy inference system (ANFIS) is used as the framework for the box-and-ellipse-based ANFIS (BE-ANFIS). Illumination adjustment is used to overcome the nonuniform illumination problem. The proposed BE-ANFIS is trained using 120 rust images of the size of 256...

Maximizing intra-individual correlations for illumination-insensitive face recognition

Abstract: Illumination variation has been one of the most intractable problems in face recognition and many approaches have been proposed to handle illumination problem in the last decades of years. The key problem is how to get stable similarity measurements between two face images of the same individual but captured under dramatically different lighting conditions. We propose a framework to optimize the illumination normalization for a pair of gallery and probe face images by maximizing a correlation (MAC) between them. The illumination normalization in the proposed framework tends to maximize the intra-individual correlations instead of both the inter- and intra-individual correlations. Experiments on Extended YaleB and CMU-PIE face databases show the effectiveness of our proposed approach in face recognition across varying lighting conditions.

Importance of virtual illumination technique in the illumination education

Abstract: Fundamental topic of Illumination consists of production, distribution, economy and measurement of light Besides, behaviors of people towards light are studied Illumination is a major topic in electrical engineering and architecture in our age Any field to be illuminated should be analyzed as a special problem However, solution to the illumination problem can only be found by electrical engineers having a voice in light production and architects working together Illumination education has only started in recent past in our country In the past, in many applications too many or wrong type lighting fixtures were used mistakenly due to ignorance Since illumination became a separate field in our universities, use of computers in illumination education has increased rapidly Computers are used in preparing illumination projects both to measure and to visualize A designer can make virtual and natural lighting measurements using computers In general, computer programmers are used in illumination technique to design fixtures, to measure and evaluate interior and exterior lighting In addition to this, virtual illumination technique should be used in education in order to be able to visualize the lighting projects in three dimensions