Vessel enhancement based an improved bilateral filter for coronary angiography

The effectiveness of the standard bilateral filter is rather good in some cases for lots of images. It could not only smooth images, but also preserve the edges of the images simultaneously. However, the shape of coronary angiography images performing complex, the diameters of blood vessels changing tremendously and image noise etc. greatly increased the difficulty of image processing for coronary angiography. What´s more, the contrast ratio between the vascular structure shown in coronary angiography images and the background is generally rather low. Therefore, the standard bilateral filter tends to blur the edges of blood vessels for coronary angiography images. It is indispensable to develop an improved bilateral filtering method to enhance images for coronary angiography.