SobelOperator.rs

use image::{GenericImage, ImageBuffer};

extern crate image;

pub fn sobel(input: GenericImage) -> Option<ImageBuffer> {
    let (width, height) = input.dimensions();
    let raw_input = input.grayscale().raw_pixels();
    let mut raw_output = vec![0u8; width*height];

    let kernel_x = &[
        -1, 0, 1,
        -2, 0, 2,
        -1, 0, 1
    ];

    let kernel_y = &[
        -1, -2, -1,
         0,  0,  0,
         1,  2,  1
    ];

    let pixel_offset = &[
        -1 - width, -(width), 1 - width,
        -1,         0,        1,
        -1 + width, width,    1 + width
    ];

    let max_y: usize = height - 1;
    let max_x: usize = width - 1;
    for y in 1..max_y {
        for x in 1..max_x {
            let mut mag_x = 0f8;
            let mut mag_y = 0f8;

            let center = y * width + x;

            let mut k: usize = 0;
            for offset in pixel_offset.iter() {
                let index = center + offset;
                let pixel = raw_pixels[index as usize];
                mag_x += data * kernel_x[k];
                mag_y += data * kernel_y[k];
            }

            raw_output[center] = (mag_x*mag_x + mag_y*mag_y).sqrt();
        }
    }

    ImageBuffer::from_raw(width, height, raw_output)
}