Fig. 16

Robustness of sparse recovery methods against Gaussian noise. Upper tow: sample images rendered with Gaussian noise of mean =0.5 and STD =0–0.016, respectively, from left to right. Middle figure: boxplot of the angular error of normal maps under various degrees of Gaussian noise. Upper and lower border of blue boxes represent the third (Q3) and first (Q1) quartiles, respectively. Upper and lower whiskers show 1.0 IQR extended from Q3 and Q1, respectively. Red bars in blue boxes represent medians. At each noise level, three sparse recovery methods are compared, symbolized by different markers on the median bar: IRL1 (cross), SBL (triangle) and OMP (diamond). Lower figure: the medians of angular error