## 3 Experimental Results and Evaluations
To evaluate color or hue shift and color leakage in perspective, in Figure 8, CIE LAB color space-based gamut area [28] is used to measure the target image (Figure 4). (a) shows the gamut area of an original image and the L* axis is from top to bottom (L+ for top and L- for bottom). The maximum L+ is 100 and indicates a perfect reflecting diffuser. The minimum L- is zero and appears black. The a* and b* axes have no limits. Positive a* (or a+) is red and negative a* (or a-) is green. Positive b* (or b+) appears yellow and negative b* (or b-) appears blue. The gamut area of the original image is biased \begin{table}
\begin{tabular}{c c c c c} \hline  & **iCAM06** &
\begin{tabular}{c} **[PERSON]’s** \\ **Method** \\ \end{tabular} & **[PERSON]’s Method** & **Proposed Method** \\ \hline Computational cost & 8.6238 & 1.986 & 5.89 & 29.7170 \\ \hline \end{tabular}
\end{table} 
Table 1: Comparative evaluation of computational cost between iCAM06, [PERSON]’s method, [PERSON]’s method, and the proposed method (units: per seconds). Figure 5: “aligned_00165” images with (**a**) an original HDRI, and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. in both red and red-blue directions. (b) shows the gamut area of the resulting image tone-mapped by the iCAM06. The biased regions increase in both red and red-blue directions. Noticeably, the resulting image is overall affected by color or hue shift and color leakage. (c) shows the gamut area of the resulting image processed by [PERSON]'s method. The gamut area is biased in a blue direction. In contrast, (d) shows that the biased region decreases in the gamut area in the resulting image tone-mapped by [PERSON]'s method. (e) shows the gamut area in the resulting image tone-mapped by the proposed method where the biased region decreases to some extent, compared to those of its conventional counterparts. Figure 9 is the histograms of the images in Figure 4 and represents the dynamic range in the L* color space. The brightness of the resulting image processed by the proposed method increases compared to those of its conventional counterparts. Figure 10 shows the resulting tone-mapped images of the captured images under five standard illuminations. Figure 11 is CIEL*a*b* [29], Ref [30]--based comparative evaluation of color difference (\(\Delta E_{ab}\)) between the original images and the resulting tone-mapped images as shown in Figure 10. As compared in Figure 11, the proposed method results in lower differences than its conventional counterparts, meaning the proposed method records the state-of-the-art performance in terms of color reproduction. Figure 6: “aligned_00260” images with (**a**) an original HDRI, and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. Figure 8: Gamut areas of Figure 4 images: (**a**) an original HDRI and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. Figure 7: Other images with (**a**) an original HDRI and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. Figure 10: (**a**) Original images captured under five standard illuminations and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. Figure 9: Histograms of Figure 4 images: (**a**) an original image and resulting images of (**b**) iCAM06, (**c**) [PERSON]’s method, (**d**) [PERSON]’s method, and (**e**) the proposed method. Next, CIEL*a*b*-based colorfulness [29] is assessed and compared in Figure 12. The proposed method records higher values than its conventional counterparts except CWF and D65 which in fact perform better in [PERSON]'s method than the proposed method.