rust opencv test

Cargo.toml

[package]
name = "rust-ela"
version = "0.1.0"
edition = "2018"

[dependencies]
opencv = {version = "0.46", features = ["contrib"]}

main.rs

use std::convert::TryInto;
use std::char;
use std::env;

use opencv::prelude::*;
use opencv::core::Mat;
use opencv::highgui;
use opencv::imgcodecs;
use opencv::imgproc;


fn main() {
    let args: Vec<String> = env::args().collect();
    if args.len() <= 1 {
        panic!("Call with an image plz");
    }
    load(&args[1]);
}

fn load(path: &str) {
    let src: Mat = imgcodecs::imread(path, 1).unwrap();
    if src.empty().unwrap() {
        panic!("Image is empty");
    }
    let mut hsv : Mat = Mat::default().unwrap();
    imgproc::cvt_color(&src, &mut hsv, imgproc::COLOR_BGR2HSV, 3).unwrap();

    highgui::named_window("Source", highgui::WindowFlags::WINDOW_FREERATIO as i32).unwrap();
    highgui::imshow("Source", &src).unwrap();
    highgui::named_window("HSV", highgui::WindowFlags::WINDOW_FREERATIO as i32).unwrap();
    highgui::imshow("HSV", &hsv).unwrap();
    
    loop {
        let key_raw : u32 = highgui::wait_key(0).unwrap().try_into().unwrap();
        if let Some(key) = char::from_u32(key_raw) {
            if key == 'q' || key == '\u{1b}' { break; } // press q or esc
        }
    }
}

shell.nix

with import <nixpkgs> {};
stdenv.mkDerivation {
  name = "env";
  nativeBuildInputs = [ pkg-config ];
  buildInputs = [
    opencv
  ];
}