distance_transform/
lib.rs

1//! This crate provides an implementation of a distance transform of binary 
2//! grids using Squared Euclidean distances. It is a port of the C++
3//! implementation of [Distance Transforms of Sampled Functions][1] by
4//! P. Felzenszwalb and D. Huttenlocher.
5//! 
6//! [1]: http://cs.brown.edu/~pff/dt/
7//! 
8//! # Examples
9//! To use the functions inside module `distance_transform::utils` you need to
10//! compile this crate with the feature image-utils.
11//!
12//! ```
13//! extern crate distance_transform;
14//! extern crate image;
15//! 
16//! use distance_transform::*;
17//! use distance_transform::utils;
18//! use std::fs::File;
19//! 
20//! fn main() {
21//!     // create a 128x128 binary image
22//!     let imgwidth = 128usize;
23//!     let imgheight = 128usize;
24//!     let mut bimg = BoolGrid::new(imgwidth, imgheight);
25//! 
26//!     // draw a circle
27//!     for (x, y, value) in bimg.iter_mut() {
28//!         let pos = (x as isize - 64)*(x as isize - 64)
29//!                 + (y as isize - 64)*(y as isize - 64);
30//!         *value = pos < 32*32 && pos > 31*31;
31//!     }
32//! 
33//!     // do the distance transformation and
34//!     // take the square root since squared distances are calculated
35//!     let fmm = utils::sqrt_img(dt2d(&bimg));
36//! 
37//!     // scale values to range [0, 255] and save as image
38//!     let fmm_img = utils::min_max_scaling(&fmm, &(0., 255.));
39//!     let ref mut fmm_out = File::create("fmm_out.png").unwrap();
40//!     utils::save_float_grid(&fmm_img, fmm_out, image::PNG).unwrap();
41//! }
42//! ```
43
44pub mod grid;
45pub use grid::*;
46
47#[cfg(feature = "image-utils")]
48pub mod utils;
49#[cfg(feature = "image-utils")]
50pub use utils::*;
51
52pub mod dt;
53pub use dt::*;