Contrast Stretching

1. Linear Contrast Stretching:

$$\text{Output pixel value}=\left(\frac{\text{Input pixel value}-\text{Min}}{\text{Max}-\text{Min}}\right)\times \text{NewMax}+\text{NewMin}$$

2. Piecewise Linear Contrast Stretching: #explore

$$\text{Output pixel value}=\{\begin{array}{ll}\text{Slope1}\times (\text{Input pixel value})& \text{if }0\le \text{Input pixel value}<\text{Threshold1}\\ \text{Slope2}\times (\text{Input pixel value}-\text{Threshold1})+\text{S1}& \text{if }\text{Threshold1}\le \text{Input pixel value}<\text{Threshold2}\\ \text{Slope3}\times (\text{Input pixel value}-\text{Threshold2})+\text{S2}& \text{if }\text{Threshold2}\le \text{Input pixel value}\le \text{L-1}\end{array}$$

References

• Contrast Stretching and intensity level Slicing in digital image processing with examples - YouTube
• Contrast Stretching in Digital Image Processing - YouTube