Fig. 17
From: Robust surface normal estimation via greedy sparse regression
Robustness of sparse recovery methods against salt and pepper noise. Upper row: sample images rendered with salt and pepper noise of density = 0–4 %, respectively, from left to right. Middle figure: boxplot of the angular error of normal maps under various degrees of salt and pepper noise. Upper and lower border of blue boxes represent 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, four 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