Subjective Image Quality Assessment at the Threshold Level

A subjective method for assessing image quality at the threshold level is presented. The assessment methodology has a trichotomous (3-way) structure. It looks at some problems associated with subjective assessments, particularly fatigue and scanning effects. In addition, it addresses the elusive issue of the minimum sample size necessary to achieve statistical relevance in subjective tests. This leads to the question of the reliability of subjects, a problem which may be resolved with a robust assessment method.