ISO 20462-3:2012 Photography — Psychophysical experimental methods for estimating image quality — Part 3: Quality ruler method
ISO 20462-1, ISO 20462-2 and ISO 20462-3 address the need for documented means of determining image quality in a calibrated fashion. The quality ruler method described in ISO 20462-3 is particularly suitable for measuring quality differences exceeding one JND. With suitable reference stimuli, the quality ruler method permits the results to be reported using the Standard Quality Scale (SQS).
As stated in ISO 20462-3, the reflection prints calibrated against the absolute SQS, referred to as standard reference stimuli (SRS), and the calibrated softcopy digital reference stimuli (DRS), are available here.
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ISO 20462-3 Set of Photographic Digital Reference Stimuli
This digital package includes two zip files. The first of the two zip files contains the digital reference image set, supporting documentation, and related data files. These images, when displayed on a high-quality monitor and viewed correctly, will have approximately known absolute Standard Quality Scale (SQS) values, and accurately known relative SQS values (JNDs). The SQS is an absolute scale of image quality and the ruler images supplied, when displayed as described, are calibrated against the SQS.
The second of the two zip files contains a MATLAB application that implements an improved version of the psychophysical method described in ISO 20462-3, Part 3, which allows quantification of the overall image quality of test images using the Standard Quality Scale (SQS) of that same standard. The software application can be used on both Mac and PC platforms.
These reference image files and the supporting MATLAB application are offered for use in image quality tests based on ISO 20462-3, Photography -- Psychophysical experimental methods for estimating image quality -- Part 3: Quality ruler method. $215, including shipping.
ISO 20462-3 Set of Photographic Standard Reference Stimuli
These hardcopy reference prints are offered for use in image quality tests based on ISO 20462-3, Photography -- Psychophysical experimental methods for estimating image quality -- Part 3: Quality ruler method. $215, including shipping.