zune-image

Zune-image

An (opinionated) image library

This is the main library tying most of the zune- family of image decoders, encoders and image processors and image libraries

Supported formats

Features

Image decoders and encoders

Each image decoder and encoder can be disabled or enabled by toggling it's feature, e.g to only include jpeg decoding and encoding, one can use

zune-image={version="0.4",default-features=false,features=["jpeg"]}

Other features

• serde: Enable serde support for serializing image metadata, adds serde as a dependency

• log: Enable printing information via log crate

• simd: Enable SIMD support for certain image operations,

• this just enables explicitly written simd code, not compiler autovectorization which may generate simd

• threads: Enables support for running some operations in multiple threads, if this is disabled, the library can run in areas which lack support for threading e.g wasm

• image-formats: Blanket feature to include all supported image formats

• metadata: Enable parsing of exif data, adds kamadak-exif as a dependency

• all: Enables all the above features

DecoderTrait, OperationsTrait and EncoderTrait

These traits encapsulate the main operations expected to be performed by an image library

• DecoderTrait: Any item implementing this can decode an image into the library's Image representation
• OperationsTrait: Any item implementing this can manipulate an Image modifying appropriate fields where necessary
• EncoderTrait: Any item implementing this can take an Image and encode it to a desired function

Representation of images

All images are represented as an Image struct, this doesn't matter if the image is Grayscale, RGB, animated or represented by f32, this allows easy interoperability and simpler api at the cost of a slightly complex internal API

You can create images via the from_ methods or read an image file via Image.open

Examples

• Generating fractals, the same example as image crate

use zune_core::colorspace::ColorSpace;

fn main() {
    let img_x = 800;
    let img_y = 800;

    let scale_x = 3.0 / img_x as f32;
    let scale_y = 3.0 / img_y as f32;

    let mut image = zune_image::image::Image::from_fn(img_x, img_y, ColorSpace::RGB, |y, x, px| {
        let r = (0.3 * x as f32) as u8;
        let b = (0.3 * y as f32) as u8;

        // colorspace channels are three, so we must set three pixels
        px[0] = r;
        px[1] = 0;
        px[2] = b;
    });

    // This may actually be combined with the function `from_fn` above.
    // But it tries to match the image example given as much as possible
    //
    // we have to annotate our image is `u8` so that it works
    image
        .modify_pixels_mut::<u8, _>(|y, x, px| {
            let cx = y as f32 * scale_x - 1.5;
            let cy = x as f32 * scale_y - 1.5;

            let c = num_complex::Complex::new(-0.4, 0.6);
            let mut z = num_complex::Complex::new(cx, cy);

            let mut i = 0;
            while i < 255 && z.norm() <= 2.0 {
                z = z * z + c;
                i += 1;
            }
            // write it
            *px[1] = i as u8;
        })
        .unwrap();

    image.save("./fractals.jpg").unwrap();
}