Seven Challenges in Image Quality Assessment: Past, Present, and Future Research

Figure 20

Subjective ratings of perceived distortion for images containing both structural distortion and additive white noise. In each graph, the horizontal axis denotes the total RMS contrast of the combined distortions and the vertical axis denotes perceived distortion relative to the corresponding original image; error bars denote standard errors of the means. Black circles: results for 𝐶_struct∈[0.1,0.3] and 𝐶_noise=0. White circles: results for 𝐶_struct=0 and 𝐶_noise∈[0.1,0.3]. Gray squares: results for 𝐶_struct=0.1 and 𝐶_noise∈[0.1,0.3]. White squares: results for 𝐶_struct=0.15 and 𝐶_noise∈[0.1,0.3]. Black triangles: results for 𝐶_struct=0.2 and 𝐶_noise∈[0.1,0.3]. Gray triangles: results for 𝐶_struct=0.25 and 𝐶_noise∈[0.1,0.3]. White triangles: results for 𝐶_struct=0.3 and 𝐶_noise∈[0.1,0.3]. Note that, for the image baby, the contrasts are halved. Figure from [59].

(a)

(b)

(c)

(d)