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An Approach to Improve the Quality of Infrared Images of Vein-Patterns
Department of Electronic Engineering, Hwa Hsia Institute of Technology, 111 Gong Jhuan Rd., Chung Ho district, New Taipei City, 23568, Taiwan
Department of Information and Computer Engineering, Chung Yuan Christian University, 200 Chung Pei Rd., Chung Li City, 32023, Taiwan
Received: 30 September 2011; in revised form: 23 November 2011 / Accepted: 29 November 2011 / Published: 1 December 2011
Abstract: This study develops an approach to improve the quality of infrared (IR) images of vein-patterns, which usually have noise, low contrast, low brightness and small objects of interest, thus requiring preprocessing to improve their quality. The main characteristics of the proposed approach are that no prior knowledge about the IR image is necessary and no parameters must be preset. Two main goals are sought: impulse noise reduction and adaptive contrast enhancement technologies. In our study, a fast median-based filter (FMBF) is developed as a noise reduction method. It is based on an IR imaging mechanism to detect the noisy pixels and on a modified median-based filter to remove the noisy pixels in IR images. FMBF has the advantage of a low computation load. In addition, FMBF can retain reasonably good edges and texture information when the size of the filter window increases. The most important advantage is that the peak signal-to-noise ratio (PSNR) caused by FMBF is higher than the PSNR caused by the median filter. A hybrid cumulative histogram equalization (HCHE) is proposed for adaptive contrast enhancement. HCHE can automatically generate a hybrid cumulative histogram (HCH) based on two different pieces of information about the image histogram. HCHE can improve the enhancement effect on hot objects rather than background. The experimental results are addressed and demonstrate that the proposed approach is feasible for use as an effective and adaptive process for enhancing the quality of IR vein-pattern images.
Keywords: noise removal; noise detection; adaptive contrast enhancement; hybrid cumulative histogram equalization
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MDPI and ACS Style
Lin, C.-L. An Approach to Improve the Quality of Infrared Images of Vein-Patterns. Sensors 2011, 11, 11447-11463.
Lin C-L. An Approach to Improve the Quality of Infrared Images of Vein-Patterns. Sensors. 2011; 11(12):11447-11463.
Lin, Chih-Lung. 2011. "An Approach to Improve the Quality of Infrared Images of Vein-Patterns." Sensors 11, no. 12: 11447-11463.