Spinal curvature determination from x-ray image using GVF snake

Scoliosis is where the spine is curved, forming a "C" or "S" shape. The treatments are differs depending on the severity of Cobb Angle. But Cobb Angle measurement has a very low accuracy because of the unclear feature of spine in x-ray image. This paper discuss about spinal curvature determination using GVF Snake as the segmentation method and modified top-hat filter as pre-processing method. GVF Snake could fit the "S" shape best with parameters alpha=0.9, beta=0.5, and gamma=0.3. 10 frontal spinal x-ray images of scoliosis patients were used as segmentation samples. The modified top-hat filter is used for pre-processing the image with combination of disk sizes and attenuation factors of 1, 3, 5, 7, and 9. The average error of the qualified contour results is 6569 pixels. The best result gave an error of 3118 which is still couldn´t fit the desired contour well.