Table 4. Mean and standard deviation of luminance statistics within each stimulus group. Correlation coefficients between the statistics of original images and all stimulus groups.
| Stimulus group | Luminance statistics |
||||
|---|---|---|---|---|---|
| Mean | Std. deviation | Skewness | Kurtosis | ||
| Original | Mean | 22.30 | 9.09 | 2.36 | 8.93 |
| Std. deviation | 1.08 | 1.17 | 1.22 | 7.18 | |
| Correlation | 1.00 | 1.00 | 1.00 | 1.00 | |
| 1 to All | Mean | 20.40 | 9.09 | 2.37 | 8.92 |
| Std. deviation | 0.21 | 1.17 | 1.22 | 7.17 | |
| Correlation | 0.28 | 1.00 | 1.00 | 1.00 | |
| 57 to All | Mean | 22.29 | 9.02 | 2.32 | 8.76 |
| Std. deviation | 0.24 | 1.20 | 1.25 | 7.15 | |
| Correlation | −0.05 | 1.00 | 1.00 | 1.00 | |
| 169 to All | Mean | 23.26 | 8.96 | 2.29 | 8.42 |
| Std. deviation | 0.19 | 1.11 | 1.20 | 6.92 | |
| Correlation | 0.41 | 1.00 | 1.00 | 1.00 | |