tiff-dec v0.3.4

tiff-dec

Javascript TIFF file decoder library built using wasm-pack and Rust.

Example - Vanilla JS

import * as wasm from "tiff-dec";

let tif = fetch("./img/grey8.tif")
    .then((res) => res.arrayBuffer())
    .then((buf) => {
        var uint8 = new Uint8Array(buf);
        return new Promise((resolve, reject) => {
            const img = wasm.decode_image(uint8);

            const metadata = img.metadata;

            const decoded = wasm.to_decoded_u8(img);
            resolve({ data: decoded, metadata: metadata });
        });
    });

tif.then((decoded) => {
    console.log(decoded.data.length);
    console.log("width: ", decoded.metadata.width, " height: ", decoded.metadata.height);
});

Check out the full example in examples/js

Example - React with Typescript

examples/ts

async import of wasm module

// Fetches asynchronous files and dependencies
const fetchAsync = async () => {
    const wasm = await import('tiff-dec');
    const image = await fetch('./m51.tif')
        .then((tif) => {
            if (tif.status < 299)
                return tif.arrayBuffer()
            else
                throw new Error("could not recieve tif");
        })
        .then((buff) => new Uint8Array(buff));
    return { wasm, image };
}

...

// mount the component and decode images
// images can be decoded anytime after the
// wasm is loaded
useEffect(() => {
    const fetchFiles = async () => {
        try {
            // wasm module asynchronously loaded and image retrieval
            const { wasm: wasmModule, image: galaxy } = await fetchAsync();

            // decoding image using `tiff-dec` package
            const initialDecodedImage = wasmModule.decode_image(galaxy);
            const loadedMetadata = initialDecodedImage.metadata;
            const initialDecodedImageData = wasmModule.to_decoded_u16(initialDecodedImage);

            // image processing parameter calculation
            let imageHistoMinMax: ContrastParams = preDepth(loadedMetadata.bit_depth, wasmModule);
            let maxContrast = imageHistoMinMax.max;

            // set state
            setLoaded(true);
            setWasm(wasmModule);

            ... 
            
        } catch (e) {
            // more state
            setError({ error: e });
            setLoaded(false);
        }
    }
    fetchFiles();
}, []);

...

Building JS/Wasm package from source

Check out wasm-pack here for more information