A Full- Reference Quality Assessment Metric for Cartoon Images

Cartoon images are illustrations that are typically drawn, sometimes animated, in an unrealistic or semi-realistic style, which are widely applied in multimedia services. However, in some post-production processes as well as transmission systems, cartoon images are inevitably distorted by wrong color arrangement and compression. Therefore, it is urgent to carry out image quality assessment (IQA) metrics to automatically predict the perceptual quality levels of distorted cartoon images. Nevertheless, the existing mainstream IQA metrics are specially developed for natural scene images (NSIs). Due to the statistical difference in structure and color aspects between cartoon images and NSIs, the scores predicted by such metrics are often inconsistent with the human vision system (HVS) for cartoon images. To further improve the performance of cartoon image quality assessment (C-IQA) methods and provide guidance for practical applications, we propose a full-reference (FR) IQA method to tackle the challenge of C-IQA. Specifically, the proposed method extracts edge and texture features to analyze the structural error. Then the moment and entropy of various color spaces are computed to reflect color distortions. Then the features are regressed into quality scores with the assistance of a support vector regression (SVR) model. Experimental results show that our metric outperforms the mainstream FR-IQA metrics, which indicates that the proposed method is more capable of modeling the visual quality loss of cartoon images.