imagerExtra (version 1.3.2)

EqualizeDP: Double Plateaus Histogram Equalization

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

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

# NOT RUN {
g <- grayscale(dogs)
layout(matrix(1:2, 1, 2))
plot(g, main = "Original")
EqualizeDP(g, 20, 186) %>% plot(main = "Contrast Enhanced")
# }