此crate提供了一种使用平方欧几里得距离进行二进制网格距离变换的实现。它是P. Felzenszwalb和D. Huttenlocher的Distance Transforms of Sampled Functions C++实现的移植。

示例

要使用模块distance_transform::utils中的函数，需要编译此crate时启用image-utils功能。

extern crate distance_transform;
extern crate image;

use distance_transform::*;
use distance_transform::utils;
use std::fs::File;

fn main() {
    // create a 128x128 binary image
    let imgwidth = 128usize;
    let imgheight = 128usize;
    let mut bimg = BoolGrid::new(imgwidth, imgheight);

    // draw a circle
    for (x, y, value) in bimg.iter_mut() {
        let pos = (x as isize - 64)*(x as isize - 64)
                + (y as isize - 64)*(y as isize - 64);
        *value = pos < 32*32 && pos > 31*31;
    }

    // do the distance transformation and
    // take the square root since squared distances are calculated
    let fmm = utils::sqrt_img(dt2d(&bimg));

    // scale values to range [0, 255] and save as image
    let fmm_img = utils::min_max_scaling(&fmm, &(0., 255.));
    let ref mut fmm_out = File::create("fmm_out.png").unwrap();
    utils::save_float_grid(&fmm_img, fmm_out, image::PNG).unwrap();
}