Retinal image vessel segmentation and their branching pattern are used for automated screening and diagnosis of diabetic retinopathy. Vascular pattern is normally not visible in retinal images. We present a method that uses 2-D Gabor wavelet and sharpening filter to enhance and sharpen the vascular pattern respectively. Our technique extracts the vessels from sharpened retinal image using edge detection algorithm and applies morphological operation for their refinement. This technique is tested on publicly available DRIVE database of manually labeled images. The validation of our retinal image vessel segmentation technique is supported by experimental results.