Enhancement of Sight Effectiveness by Dual Infrared System E

Abstract- The problem of objective evaluation of multisensor image fusion strategies is analysed for the design of a dual infrared system. Such a system should be used to enhance the sight effectiveness in assisting a driver or a pilot in bad visibility co

Enhancement of Sight Effectiveness by Dual Infrared System: Evaluation of Image Fusion Strategies

G. Corsini , M. Diani , A. Masini

Dipartimento di Ingegneria dell’Informazione

Università di Pisa , Italy

Abstract - The problem of objective evaluation of multi-sensor image fusion strategies is analysed for the design of a dual infrared system. Such a system should be used to enhance the sight effectiveness in assisting a driver or a pilot in bad visibility conditions. Two no-reference indexes are used to quantify the performance of different image fusion methods. Numerical results are presented and discussed in terms of the quality of the fused images.

Index Terms – Image/video processing. Data fusion. Image quality indexes.

I. INTRODUCTION Image fusion methods combine the visual information contained into different source images in a single

composite one to enhance human perception and interpretation capabilities.

Such a tool is of paramount importance in many applications, where it is crucial to extend human vision to improve the operator performances. An interesting application can be easily found in the field of vehicle driving. In fact, the use of different infrared sensors can be

very useful for the perception of objects or obstacles in bad visibility conditions (night, rain and fog) and, consequently, can aid a car driver or aircraft pilot. Multispectral infrared image sources have to be fused to synthesize the salient information collected in the different channels enabling a better scene interpretation and

improving the situational awareness.

As a matter of fact, Image Fusion (IF) techniques are expected to achieve several objectives which can be summarized as follows:

a) integration of images from different sensors has to produce information that cannot be obtained by viewing the sensor outputs separately and consecutively; b) the information extracted from the input images must be salient with respect to the specific application and must improve the image semantic interpretation. Obviously, fusion methods should not discard any salient information from each source; c) an essential problem in merging images is pattern conservation: important details of the

component images must be preserved in the resulting composite image. Therefore, the incomplete representation of objects in one image may be integrated by information from the other one (complementary information); d) the fusion process should not introduce any artefacts which M. Cavallini Galileo Avionica

Campi Bisenzio, Firenze, Italy

can distract or mislead a human observer; e) the merging operation shall harmonise the disparity between the images coming from the input sensors. For example, the sensor output images could not be equally reliable. Such disparities have to be taken into account when fusing the information from such sources; g) the fusion must be reliable, robust and has to have the capability to tolerate disturbances and errors (noise and misregistration); h) common but contrast reversal information must be treated

in an appropriate way: there could be various objects and regions that occur in both images but with opposite

contrast. Therefore, in this case, the direct approach of

adding and averaging the source images is not satisfactory.

A fundamental issue of image fusion techniques is the process for evaluating the performances of a fusion

scheme. In fact, the improvement depends on the particular scenario, the used sensors, the lighting conditions and, obviously, on the capabilities of the human observer. Then, it is very difficult to define general procedures to compare fusion results.

Traditionally, the quality of video sequences is evaluated subjectively by an appropriate number of human evaluators. This method has two main disadvantages: it requires an appropriate number of evaluators (thus it is time consuming and expensive), and it cannot be done in real time.

As a result, a considerable research effort has been addressed to the development of automatic objective methods for video quality measurement. Performance measures are essential for various reasons: 1) to ascertain

the possible benefits of fusion; 2) to compare results obtained with different algorithms; 3) to obtain an optimal setting of parameters for tuning a specific fusion algorithm. A good quality index should extract all the important information from a perceptive point of view from the input images and measure the ability of the fusion process in transferring with the highest accuracy (that is minimising the number of artefacts or the amount of distortions) this information into the final image.

In this paper we propose some figures of merit for the evaluation and the comparison of fusion strategies in a dual infrared system, used to enhance the sight effectiveness in assisting a driver or a pilot in bad visibility conditions. Namely, we consider the two figures of merit, recently proposed in the literature by Xydeas and Petrovic [1] and

Abstract- The problem of objective evaluation of multisensor image fusion strategies is analysed for the design of a dual infrared system. Such a system should be used to enhance the sight effectiveness in assisting a driver or a pilot in bad visibility co

Wang-Bovik [2] and discuss their capability of assessing the performance of different fusion strategies applied to an experimental data set.

We refer to an experiment where, for the first time, presented: they utilize local measures to estimate the level of the salient information tr …… 此处隐藏：24394字，全部文档内容请下载后查看。喜欢就下载吧 ……