Embedding image

[szabgab]

I would like to embed an image into another image. I could not find a method for this so I wrote a small example.
Is there a better way to do it?

use image::{GenericImageView, ImageBuffer, RgbaImage};

fn main() {
    let img = create_image();

    let img = embed_image(img, "rust.png", 100, 50);

    img.save("created.png").unwrap();

}

fn embed_image(mut img: RgbaImage, infile: &str, start_x: u32, start_y: u32) -> RgbaImage {
    let logo = image::open(infile).unwrap();

    println!("Base image: width={}, height={}", img.width(), img.height());
    println!("Embedding:  width={}, height={}", logo.width(), logo.height());

    if start_x + logo.width() > img.width() {
        println!("Does not fit in width");
        return img;
    }
    if start_y + logo.height() > img.height() {
        println!("Does not fit in height");
        return img;
    }

    for x in 0..logo.width() {
        for y in 0..logo.height() {
            *img.get_pixel_mut(start_x + x, start_y + y) = logo.get_pixel(x, y);
        }
    }

    img
}

fn create_image() -> RgbaImage {
    let width = 300;
    let height = 200;

    let mut img: RgbaImage = ImageBuffer::new(width, height);
    let red = 0 as u8;
    let green = 255;
    let blue = 255;
    let alpha = 255;

    for x in 0..width {
        for y in 0..height {
            *img.get_pixel_mut(x, y) = image::Rgba([red, green, blue, alpha]);
        }
    }

    img    
}

[fintelia]

Your implementation looks fine. The only change I'd suggest would be swapping the two loops since that would be more cache friendly though the optimizer might do that anyway.

The replace method does roughly the same thing you're doing, but handles out of bounds slightly differently (you can click the [source] link to see how it is implemented)