This tool can be used to reduce colour bias in a colour composite image based on the technique described by Liu (1991). Colour bias is a common phenomena with colour images derived from multispectral imagery, whereby a higher average brightness value in one band results in over-representation of that band in the colour composite. The tool essentially applies a parabolic stretch to each of the three bands in a user specified RGB colour composite, forcing the histograms of each band to have the same minimum, maximum, and average values while maintaining their overall histogram shape. For greater detail on the operation of the tool, please see Liu (1991). Aside from the names of the input and output colour composite images, the user must also set the value of E, the desired output band mean, where 20 < E < 235.

## Reference

Liu, J.G. (1991) Balance contrast enhancement technique and its application in image colour composition. International Journal of Remote Sensing, 12:10.

## See Also

direct_decorrelation_stretch, histogram_matching, histogram_matching_two_images, histogram_equalization, gaussian_contrast_stretch

## Function Signature

`def balance_contrast_enhancement(self, image: Raster, band_mean: float = 100.0) -> Raster: ...`

## Project Links

WbW Homepage User Manual Support WbW