Evaluations of Image Degradation from Multiple Scan-Print

2. Image Metrics

Usually image quality is measured by computable metrics. These metrics are classified into two-fold: objective and subjective. Objective metrics (Falk, 2007; Gallager, 2001; Wang, 2011) take advantages of quantified parameters to measure the quality of perceived images while subjective metrics(Falk, 2007; Wang, 2011) are often employed to evaluate visual effects of how a viewer perceives a specific image. Figure 1 shows the classifications of the metrics which are grouped into objective and subjective categories. The objective metrics are further taken part into statistics based and human visual system oriented.

Figure 1.

Image quality metrics