Research On No Reference Image Quality Assessment Algorithm

Image is the main carrier of human to obtain information from the real world. There is an inevitable distortion in the process of image processing. Therefore, how to assess image quality quickly and efficiently has caused more and more attention. In the process of assessment,Objective assessment method of image quality can be divided into three parts according to the using degree of reference images: FRIQA,RRIQA,NRIQA. It is always difficult to obtain the original image, therefore, the research on the no reference quality assessment method has a great significance. The major contents are as follows .(1) A novel metric for no reference blurred image quality assessment based on the Haar wavelet transform is proposed. Fast Haar wavelet decomposition is applied on a blurred image.To obtain a new high frequency detail image, the high frequency subbands are weighted. Then,the detail image should be normalized in brightness. The Generalized Gaussian distribution is used to estimate parameters and then the final evaluation scores are obtained by new indicator.Experiments in the LIVE database and TID2008 database verify the validity and accuracy of the method, where, the PLCC values in LIVE database and TID2008 database are 0.8721 and 0.7813. The SROCC values in LIVE database and TID2008 database are 0.8805 and 0.7921,respectively.(2) A no reference image quality assessment algorithm based on sparse dictionary is proposed. By extracting the image features in spatial domain and frequency domain,respectively, then image features are sparse using dictionary leaning, and establish evaluation model for the sparse coefficient. The simulation experiment results in the LIVE database are consistent with the subjective evaluation results, where, the PLCC and SROCC values in LIVE database are 0.8512 and 0.8661.