应用连续小波变换检测和增强DSA血管影像的研究

Study of Continuous Wavelet Transform on Detecting and Enhancing Blood Vessel in DSA Image

数字血管减影的影像中的血管像具有对比度低的特点。本文用一种全新的思想实现 DSA影像中血管像的增强 ,即先应用小波变换技术检测血管边缘 ,使其从背景中分离出来 ,再应用对比度拉伸的方法进一步增强血管同背景的对比度。由于本文使用的连续小波变换可从不同方向上检测影像灰度变化情况 ,所以检测到的影像边缘更准确全面。而且由于噪声的小波变换的模较小 ,较好地抑制了减影像中的背景噪音 。

Low contrast is the shortcoming of the image in Digital Subtraction Angiography. This paper presents a new approach for the enhancement of blood volume in DSA image. The wavelet transform was applied to detect blood edges, and then the image contrast was enhanced by the method of contrast stretched. Because the continuous wavelet adopted in this study can detect gray variety in different orientations, the blood vessel edge detected by this algorithm is more precise and complete. Moreover, because the module of image noise by wavelet transform is smaller, the algorithm can protrude blood vessel but restrain noise in background. The Processing result showed a very good optical effect of 3 dimensional objects for medical diagnoses.