fastimageresize

Rust library for fast image resizing with using of SIMD instructions.

Supported pixel formats and available optimisations: - U8x4 - four u8 components per pixel: - native Rust-code without forced SIMD - SSE4.1 - AVX2 - I32 - one i32 component per pixel: - native Rust-code without forced SIMD - F32 - one f32 component per pixel: - native Rust-code without forced SIMD

Benchmarks

Environment: - CPU: Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz - RAM: DDR4 3000 MHz - Ubuntu 20.04 (linux 5.8) - Rust 1.54 - fastimageresize = "0.1" - glassbench = "0.3.0"

Other Rust libraries used to compare of resizing speed: - image = "0.23.14" (https://crates.io/crates/image) - resize = "0.7.2" (https://crates.io/crates/resize)

Resize algorithms: - Nearest - Convolution with Bilinear filter - Convolution with CatmullRom filter - Convolution with Lanczos3 filter

Resize RGB image 4928x3279 => 852x567

Pipeline:

src_image => resize => dst_image

Source image nasa-4928x3279.png
Numbers in table is mean duration of image resizing in milliseconds.

| | Nearest | Bilinear | CatmullRom | Lanczos3 | |------------|:-------:|:--------:|:----------:|:--------:| | image | 105.194 | 198.359 | 289.810 | 381.861 | | resize | 16.186 | 71.964 | 132.501 | 192.672 | | fir rust | 0.476 | 55.284 | 84.732 | 117.519 | | fir sse4.1 | - | 11.848 | 17.864 | 25.978 | | fir avx2 | - | 8.753 | 12.569 | 18.112 |

Compiled with rustflags = ["-C", "target-cpu=native"]

| | Nearest | Bilinear | CatmullRom | Lanczos3 | |------------|:-------:|:--------:|:----------:|:--------:| | image | 91.138 | 182.251 | 279.838 | 380.956 | | resize | 15.967 | 62.125 | 114.870 | 168.013 | | fir rust | 0.467 | 56.376 | 61.565 | 85.433 | | fir sse4.1 | - | 11.229 | 16.503 | 23.465 | | fir avx2 | - | 8.464 | 11.602 | 17.076 |

Resize RGBA image 4928x3279 => 852x567

Pipeline:

src_image => multiply by alpha => resize => divide by alpha => dst_image

Source image nasa-4928x3279.png
Numbers in table is mean duration of image resizing in milliseconds.

| | Nearest | Bilinear | CatmullRom | Lanczos3 | |------------|:-------:|:--------:|:----------:|:--------:| | image | 101.499 | 216.029 | 335.151 | 455.582 | | resize | 19.671 | 85.199 | 155.205 | 224.660 | | fir rust | 13.583 | 67.031 | 94.816 | 124.344 | | fir sse4.1 | 12.012 | 23.370 | 29.345 | 36.925 | | fir avx2 | 6.893 | 15.162 | 18.959 | 24.518 |

Compiled with rustflags = ["-C", "target-cpu=native"]

| | Nearest | Bilinear | CatmullRom | Lanczos3 | |------------|:-------:|:--------:|:----------:|:--------:| | image | 90.750 | 186.545 | 284.383 | 392.403 | | resize | 19.918 | 69.129 | 130.433 | 191.987 | | fir rust | 9.957 | 68.817 | 76.454 | 103.521 | | fir sse4.1 | 7.865 | 18.407 | 23.586 | 30.649 | | fir avx2 | 6.882 | 14.847 | 18.026 | 23.450 |

Example

```rust use std::io::BufWriter; use std::num::NonZeroU32;

use image::codecs::png::PngEncoder; use image::io::Reader as ImageReader; use image::{ColorType, GenericImageView};

use fastimageresize as fr;

[test]

fn resizeimageexample() { // Read source image from file let img = ImageReader::open("./data/nasa-4928x3279.png") .unwrap() .decode() .unwrap(); let width = NonZeroU32::new(img.width()).unwrap(); let height = NonZeroU32::new(img.height()).unwrap(); let srcbuffer = img.torgb8();

// Create immutable view of source image data
let src_view =
    fr::SrcImageView::from_buffer(
        width, 
        height, 
        src_buffer.as_raw(), 
        fr::PixelType::U8x4
    )
    .unwrap();

// Create wrapper that own data of destination image
let dst_width = NonZeroU32::new(1024).unwrap();
let dst_height = NonZeroU32::new(768).unwrap();
let mut dst_image = fr::ImageData::new(
    dst_width, 
    dst_height, 
    src_view.pixel_type()
);

// Get mutable view of destination image data
let mut dst_view = dst_image.dst_view();

// Create Resizer instance and resize source image 
// into buffer of destination image
let mut resizer = fr::Resizer::new(
    fr::ResizeAlg::Convolution(
        fr::FilterType::Lanczos3
    )
);
resizer.resize(&src_view, &mut dst_view);

// Write destination image as PNG-file
let mut result_buf = BufWriter::new(Vec::new());
let encoder = PngEncoder::new(&mut result_buf);
encoder
    .encode(
        dst_image.get_buffer(),
        dst_width.get(),
        dst_height.get(),
        ColorType::Rgb8,
    )
    .unwrap();

} ```