Histogram Equalization

Pre-Processing > Histogram Equalization

Equalizes image brightness and contrast across the image by performing different histogram scaling in each tile of grid of tiles whose size is defined by user [1].

1. Method

Controls desired histogram shape for the image tiles

• Uniform: Flat-histogram

• Rayleigh: Bell-shaped histogram

• Exponential: Curved histogram

2. Tiles

Number of tiles to split the image into in each direction (Recommended: 8)

3. Enhancement

Adjusts amount of contrast enhancement. Higher values result in more contrast (Recommended: 0.01)

References

[1] Zuiderveld, Karel. “Contrast Limited Adaptive Histograph Equalization.” Graphic Gems IV. San Diego: Academic Press Professional, 1994. 474–485.