An Adaptive Enhance Method Based on Unsharp Masking for Cone Beam CT Images

An Unsharp Masking based enhance method using Laplacian for sequence of CT images is proposed. In this method, local variance of each pixel is computed, according to which and the two gradient thresholds the image is divided into three regions. Different region is given different enhance coefficient, which is determined by it's local variance, and a Laplace template which is determined by corresponding gradient of current pixel. Thus, the adaptive and anisotropic enhancement of image is achieved. The results show, the enhanced images using proposed method have higher SNR, lower MSE and clearer details comparing which the traditional ones. The proposed method performs well in the enhancement of sequence of cone-beam CT images.