An Efficient Universal Noise Removal Algorithm Combining Spatial Gradient and Impulse Statistic

Table 1

Comparison of noise detectors in CR.

Noise ratio	ROAD	ROLD	RORD	DARD
Salt-and-pepper noise
10%	99.48%	99.37%	99.77%	99.87%
20%	98.75%	98.63%	99.44%	99.73%
30%	97.15%	96.74%	98.53%	99.58%
40%	93.21%	92.65%	95.86%	99.16%
50%	83.58%	83.75%	86.01%	98.89%
Random-valued impulse noise
10%	97.25%	97.38%	97.71%	97.56%
20%	94.59%	94.83%	95.68%	95.57%
30%	92.54%	92.88%	93.71%	93.54%
40%	90.62%	91.04%	91.75%	91.53%
50%	88.77%	89.31%	89.37%	88.87%
Mixed impulse noise
10%	97.26%	97.40%	97.87%	97.57%
20%	94.51%	94.77%	95.65%	95.50%
30%	92.06%	92.47%	93.48%	93.36%
40%	89.51%	90.11%	90.81%	90.77%
50%	86.53%	87.52%	87.21%	87.28%