Fast and safe image scaling in Rust

This crate provides zero unsafe fast rescaling.

Example

let img = ImageReader::open("./assets/nasa-4928x3279.png")
    .unwrap()
    .decode()
    .unwrap();
let dimensions = img.dimensions();
let transient = img.to_rgb8();

let src_size = ImageSize::new(dimensions.0 as usize, dimensions.1 as usize);
let dst_size = ImageSize::new(dimensions.0 as usize / 4, dimensions.1 as usize / 4);

let resized = resize_rgb8(&transient, src_size, dst_size, 
                          ResamplingFunction::Lanczos3).unwrap();

Example comparison time for downscale RGBA 4928x3279 8 bit image in 4 times.

cargo bench --bench resize_rgba --manifest-path ./app/Cargo.toml

	Lanczos3	Bilinear
image(aarch64)	121.19	48.89
pic-scale(aarch64)	11.89	8.92
fir(aarch64)	25.89	11.30
image(x86)	192.52	88.63
pic-scale(x86)	25.50	18.37
fir(x86)	42.89	24.13
image(x86-cpu-native)	205.64	89.02
pic-scale(x86-cpu-native)	14.39	11.31
fir(x86-cpu-native)	41.21	22.77

Example comparison time for downscale RGB 4928x3279 8 bit image in 4 times.

cargo bench --bench resize_rgb --manifest-path ./app/Cargo.toml

	Lanczos3	Bilinear
image(aarch64)	123.85	51.30
pic-scale(aarch64)	17.23	12.32
fir(aarch64)	23.61	10.53
image(x86)	201.52	90.82
pic-scale(x86)	27.17	21.08
fir(x86)	41.97	24.39
image(x86-cpu-native)	184.57	84.69
pic-scale(x86-cpu-native)	20.96	15.16
fir(x86-cpu-native)	41.49	20.38

Example comparison time for downscale RGBA 4928x3279 16 bit image in 4 times.

cargo bench --bench resize_rgba_u16 --manifest-path ./app/Cargo.toml

	Lanczos3	Bilinear
image(aarch64)	262.32	76.91
pic-scale(aarch64)	15.49	11.38
fir(aarch64)	141.78	50.08
image(x86)	196.28	107.78
pic-scale(x86)	57.48	50.85
fir(x86)	139.56	58.48
image(x86-cpu-native)	192.85	102.05
pic-scale(x86-cpu-native)	39.60	46.44
fir(x86-cpu-native)	101.48	52.58

Example comparison time for downscale RGB 4928x3279 16 bit image in 4 times.

cargo bench --bench resize_rgb_u16 --manifest-path ./app/Cargo.toml

	Lanczos3	Bilinear
image(aarch64)	130.45	57.38
pic-scale(aarch64)	16.17	12.11
fir(aarch64)	110.06	42.04
image(x86)	204.10	148.34
pic-scale(x86)	43.21	145.73
fir(x86)	210.28	51.29
image(x86-cpu-native)	190.21	98.42
pic-scale(x86-cpu-native)	33.48	28.50
fir(x86-cpu-native)	72.88	45.17

Example comparison time for downscale RGBA 4928x3279 f32 image in 4 times.

cargo bench --bench resize_rgba_f32 --manifest-path ./app/Cargo.toml

	Lanczos3	Bilinear
image(aarch64)	100.16	50.09
pic-scale(aarch64)	14.07	11.18
fir(aarch64)	105.30	37.75
image(x86)	208.25	107.84
pic-scale(x86)	33.55	28.97
fir(x86)	92.38	74.12
image(x86-cpu-native)	162.83	108.54
pic-scale(x86-cpu-native)	33.13	28.54
fir(x86-cpu-native)	56.65	59.96

This project is licensed under either of

• BSD-3-Clause License (see LICENSE)
• Apache License, Version 2.0 (see LICENSE)

at your option.