Function stretch_contrast

pub fn stretch_contrast(image: &GrayImage, lower: u8, upper: u8) -> GrayImage

Linearly stretches the contrast in an image, sending lower to 0u8 and upper to 2558u8.

Is it common to choose upper and lower values using image percentiles - see percentile.

Examples

use imageproc::contrast::stretch_contrast;

let image = gray_image!(
     0,   20,  50;
    80,  100, 255);

let lower = 20;
let upper = 100;

// Pixel intensities between 20 and 100 are linearly
// scaled so that 20 is mapped to 0 and 100 is mapped to 255.
// Pixel intensities less than 20 are sent to 0 and pixel
// intensities greater than 100 are sent to 255.
let stretched = stretch_contrast(&image, lower, upper);

let expected = gray_image!(
      0,   0,  95;
    191, 255, 255);

assert_pixels_eq!(stretched, expected);