Improving Self-Quotient Image Method of NPR

Self-quotient image (SQI) method was recently proposed, which is applicable to non-photorealistic rendering (NPR). In this paper, we analyse the deficiencies of the original SQI method in generating sketching style from various images and make some improvements on it. The basic idea is to enhance features and weaken noise by enlarging the differences of feature pixels¿ gray values between anisotropic filtrated and isotropic filtrated images and reducing the differences in other areas. The experiment results show that using the improved SQI method, we can obtain sketching style with stronger features and less noises from original photos regardless of their smoothness or noise.