The Design Of Leg Vein Image Acquisition System And Its Corresponding Segmentation Algorithm

Near-infrared imaging technology has a vital role in intravenous puncture,venousidentification and early diagnosis of varicose veins and other clinical medical operations.Yet all available vein imaging device in the market are costly that makes their application limited.In this paper,a set of human leg venous acquisition system was designed based on the difference absorption characteristics of the vein with the other tissue components in the light of a certain wavelength range(Near-infrared window).The camera of the vein collection system employed a 1/3.5 inch CMOS as the sensor chip and a lens of 2.8 mm in focal length.The light source selected the infrared LED ring array with a center wavelength of 850 nm distributed around the camera.The arrangement of the camera and light source were controlled through the acquisition card to achieve digital image acquisition and storage.The method of the adaptive histogram equalization with a limited contrast(CLAHE)was used to enhance the collected vein image.And the area of the vein has been enhanced.The effect of uneven illumination can be reduced and that was verified experimentally.The prominence of the CLAHE algorithm was proved effective in an experimental way.The segmentation algorithm that combined the integral sum image and local adaptive threshold method was not only obtained the binary image of the leg vein,but also significantly reduced the processing time.And this binary imaging after the morphological closed operation and open operation eliminates of noise patches.So the edge of the veins was smoothed in a large part.