ABSTRACT
We have extensively used two embodiments of the quality ruler, one involving hardcopy images and the other softcopy display. These two implementations differ not only physically, but also in the nature of the assessment task. This chapter, which explains both approaches in detail, is organized as follows. Sections 8.2 and 8.3 describe the hardcopy and softcopy quality rulers, respectively. Instructions to the observers are discussed in Sect. 8.4. Finally, Sect. 8.5 reviews various aspects of quality ruler performance.
