heif-rs

A Rust library to encode and decode HEIF/HEIC images using x265 and libde265, via statically-linked libheif.

⬇️ Installation

This library can be installed using Cargo. To do that, run the following command in your project's root directory:

cargo add heif-rs

The crate links as heif, so you import it with use heif; regardless of the package name.

[!NOTE] The first build downloads the prebuilt static binaries for your platform, so an internet connection is required (see Troubleshooting for offline builds).

🤖 Usage

Here are some examples of how to encode and decode HEIC images using this library. These snippets don't have any error handling for the sake of simplicity, but you should always check for errors in production code.

Encoding

let img = image::open("/path/to/image.png").unwrap(); // an image to be encoded
let bytes = heif::encode(&img).unwrap(); // encode the image with default settings
std::fs::write("/path/to/image.heic", &bytes).unwrap(); // save the HEIC to a file

Encoding with custom settings

use heif::{Chroma, HeifEncoder, Preset};
use image::ImageEncoder;

let img = image::open("/path/to/image.png").unwrap();
let mut bytes = Vec::new();
img.write_with_encoder(
    HeifEncoder::new(&mut bytes)
        .with_quality(80)             // 0–100, higher = better quality
        .with_preset(Preset::Slow)    // x265 speed preset (slower = better compression)
        .with_chroma(Chroma::Yuv420), // 4:2:0 / 4:2:2 / 4:4:4
).unwrap();

Decoding

let bytes = std::fs::read("/path/to/image.heic").unwrap(); // read the HEIC file
let img = heif::decode(&bytes).unwrap(); // decode it into a DynamicImage
img.save("/path/to/image.png").unwrap(); // save it in another format

Probing (header only)

Read the image dimensions and bit depth without decoding the pixels — useful for validation or thumbnailing pipelines:

let bytes = std::fs::read("/path/to/image.heic").unwrap();
let info = heif::probe(&bytes).unwrap();
println!("{}x{} @ {:?}", info.width, info.height, info.bit_depth);

The public API also exposes [encode_buffer] (encode a typed ImageBuffer directly), [HeifEncoder] / [HeifDecoder] for image-trait integration, [EncoderConfig] / [DecoderConfig] for full control, and [libheif_version].

Runnable examples

The examples/ directory has standalone programs covering each part of the API, runnable out of the box against the bundled assets:

cargo run --example encode          # encode with defaults
cargo run --example decode          # decode a HEIC to PNG
cargo run --example custom_encoder  # HeifEncoder builder (quality/preset/chroma)
cargo run --example encode_buffer   # encode a typed ImageBuffer
cargo run --example probe           # read the header without decoding pixels
cargo run --example roundtrip       # encode then decode
cargo run --example high_bit_depth  # 10-bit encoding via EncoderConfig
cargo run --example parallel_encode # concurrent encoding
cargo run --example version         # print the linked libheif version

💣 Troubleshooting

High bit depth (10/12-bit) encoding fails

libheif supports 8/10/12-bit HEIC for both encode and decode. Decoding high-bit-depth HEIC works out of the box (via libde265). Encoding 10/12-bit, however, depends on the bundled x265 binary, which is currently an 8-bit build — requesting 10/12-bit output makes libheif return an encoder error. If you need high-bit-depth encoding, supply your own libheif/x265 binaries built with high-bit-depth support via the HEIF_BINARIES_DIR environment variable (see below).

My build fails because it can't download the binaries

The first build fetches the prebuilt static libraries for your platform over the network. For offline or air-gapped builds, download the archive for your target from binaries-heif, extract it, and point the build at it with the HEIF_BINARIES_DIR environment variable:

$ HEIF_BINARIES_DIR=/path/to/extracted/libs cargo build

📝 License

heif-rs is released under the Apache 2.0 License. See LICENSE for details.

👨🏾‍💻 Author

Vinicius Egidio (vinicius.io)