ISO 20462, a three-pan standard, is being developed by WG18 (Electronic Still Picture Imaging) of TC42 (Photography). All three parts will be published this year. This standard describes two novel perceptual methods, the triplet comparison technique and the quality ruler, that yield results calibrated in just noticeable differences (JNDs). Part 1, “Overview of psychophysical elements, ” discusses specifications regarding observers, test stimuli, instructions, viewing conditions, data analysis, and reporting of results. Part 2, “Triplet comparison method, ” describes a technique involving simultaneous five-point scaling of sets of three stimuli at a time, arranged so that all possible pairs of stimuli are compared exactly once. Part 3, “Quality ruler method, ” describes a real-time technique optimized for obtaining assessments over a wider range of image quality.