Image Quality Scale (IQS) for Compressed Images Quality Measurement

In this paper, an objective measurement to evaluate the quality of gray scale compressed images, Image Quality Scale (IQS), has been proposed. It is defined by 5 measurements, which are Mean Square Error, Edge Measurement, Correlation Measurement, Human Visual System Measurement and Spectrum Measurement. The evaluation result is rated into 5-level grading scale, 1 to 5, which is comparable to Mean Opinion Score (MOS). The objective of this paper is to provide defining method, definition, and reliability of IQS. From the experiments, we demonstrate that the reliability (correlation coefficient) of IQS is higher than PSNR, MSE, Edge Measurement, Cori-elation Measurement, HVS Measurement and Spectrum Measurement. Therefore, the IQS is reliable and can be used to evaluate the quality of compressed images, JPEG and JPEG2000.