基于近红外图像质量评价的静脉图像采集系统

On the Vein Image Capturing System Based on Near-Infrared Image Quality Assessment

以手背静脉图像采集系统作为研究对象,根据图像采集对后续图像处理的影响,设计了红外光源调控装置.研究了近红外成像所生成的灰度图像的评价方法,分析了基于信息容量、能量谱-熵、伪信噪比的评价方法,以及每种方法所适用的场合,建立了基于静脉图像质量的评价方法.研究了采集图像与光强之间的关系,推导出图像质量与LED电流之间的关系,从而获得最优的光源控制调制信号.将图像质量评价结果应用到光强控制,设计了集红外采集、红外图像质量评价和红外光源调控于一体的光源装置,采集到的静脉图像符合后续处理的需要.

According to the effect of image capturing on image processing, a near-infrared source control system was designed for the hand vein image capturing system. The different assessment methods for the gray-scale images resulting from near-infrared imagery and their different applications were discussed, based on the information capacity, energy spectrum-entropy and false signal-to-noise ratio. A method was therefore proposed to assess the vein images quality, with which the relationship between image captured and light intensity was investigated so as to deduce the relationship between image quality and LED current, thus obtaining the optimal light source control/modulation signal. Applying the results of image quality assessment to light intensity control, a light source system was designed to integrate the near-infrared image capturing and image quality assessment with light source control together. As a result, the vein images meet the requirements of subsequent processing.