module CrImage::Operation::HistogramEqualize

Overview

Provides methods for histogram and histogram equalization. Follows method outlined here

If an image is particularly dark or particularly bright with low contrast, the Operation::Contrast#contrast method will only make the image darker or lighter. For images like these, equalizing the image along its histogram will produce better results.

image.contrast(10).save("contrast.jpg")
image.histogram_equalize.save("equalized.jpg")

This method does not work well when a given method has a bimodal distribution of color pixels. For example:

Direct including types

• CrImage::GrayscaleImage
• CrImage::RGBAImage

Defined in:

cr-image/operation/histogram.cr

Instance Method Summary

• #histogram(channel_type : ChannelType) : Histogram
• #histogram_equalize : self
• #histogram_equalize! : self

Instance Method Detail