Quality perception and discrimination thresholds in quantised triangle meshes

At certain stages of the graphics pipeline, and most notably during compression for transmission and storage, triangle meshes may undergo a fixed-point arithmetic quantisation of their vertex coordinates. This paper presents the results of a psychophysical experiment, where discrimination thresholds between the original unquantised triangle meshes, and the quantised at various levels of quantisation versions of them, were estimated. The experiment had a two-alternative forced choice design. Our results show that the amount of geometric information of a mesh, as measured by its filesize after compression, correlates with the discrimination threshold. On the other hand, we did not find any correlation between the discrimination thresholds and the quality of the underlying meshing, as measured by the mean aspect ration of the mesh triangles.