Figure 2. Example of image compression with various thresholding levels.

(a) Original image with 16 × 16 resolution; here, the number of phase values (that is, quanta) is sixteen. (b) Compressed image for different values of the threshold δ Only quarter-images are shown (due to symmetry) compressed respectively at 2:1−δ=1/16, 2.5:1−δ=1/8, 4:1−δ=1/4 and 4.6:1−δ=1/2. The corresponding values of the phase error ϕ_E(δ) are reported in figure (d) while the distribution of unique quanta versus quanta index is shown in c.