EqualizeDP: Double Plateaus Histogram Equalization

In imagerExtra: Extra Image Processing Library Based on 'imager'

Description

enhance contrast of image by double plateaus histogram equalization.

Usage

EqualizeDP(im, t_down, t_up, N = 1000, range = c(0, 255))

Arguments

im	a grayscale image of class cimg
t_down	lower threshold
t_up	upper threshold
N	the number of subintervals of histogram
range	range of the pixel values of image. this function assumes that the range of pixel values of of an input image is [0,255] by default. you may prefer [0,1].

Value

a grayscale image of class cimg

Author(s)

Shota Ochi

References

Kun Liang, Yong Ma, Yue Xie, Bo Zhou ,Rui Wang (2012). A new adaptive contrast enhancement algorithm for infrared images based on double plateaus histogram equalization. Infrared Phys. Technol. 55, 309-315.

Examples

g <- grayscale(dogs)
layout(matrix(1:2, 1, 2))
plot(g, main = "Original")
EqualizeDP(g, 20, 186) %>% plot(main = "Contrast Enhanced")

Example output

Loading required package: imager
Loading required package: magrittr

Attaching package: ‘imager’

The following object is masked from ‘package:magrittr’:

    add

The following objects are masked from ‘package:stats’:

    convolve, spectrum

The following object is masked from ‘package:graphics’:

    frame

The following object is masked from ‘package:base’:

    save.image

imagerExtra documentation built on May 2, 2019, 1:44 p.m.