# utif

> Fast and advanced TIFF decoder

Latest version **3.1.0** (published 2019-06-18) · MIT license · 0 weekly downloads

## Install

```sh
npm install utif
pnpm add utif
yarn add utif
bun add utif
```

## Health

**Score 28/100 (F)** — status: abandoned.

Positive: has types package; no vulnerabilities.

Warnings: low downloads; no esm support.

Negative: abandoned.

## Facts

| | |
|---|---|
| Version | 3.1.0 |
| Published | 2019-06-18 |
| First published | 2017-08-03 |
| Weekly downloads | 0 |
| License | MIT |
| TypeScript types | separate (@types/utif) |
| Module format | CommonJS |
| Dependencies | 1 |
| Unpacked size | 62.5 KB |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 497 |
| Author | photopea |
| Maintainers | photopea, scimonster |
| Keywords | tiff, image, conversion |

## Links

- npm: https://www.npmjs.com/package/utif
- Repository: https://github.com/photopea/UTIF.js
- Issues: https://github.com/photopea/UTIF.js/issues
- npm.io page: https://npm.io/package/utif

## Dependencies (1)

- [pako](https://npm.io/package/pako.md) ^1.0.5

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## Recent versions

- 3.1.0 (latest) — 2019-06-18
- 3.0.0 — 2019-02-11
- 2.0.1 — 2018-09-01
- 2.0.0 — 2018-05-10
- 1.3.0 — 2018-02-06
- 1.2.1 — 2017-12-23
- 1.2.0 — 2017-12-21
- 1.1.2 — 2017-09-25
- 1.1.1 — 2017-09-19
- 1.1.0 — 2017-08-07
- 1.0.0 — 2017-08-03

## README

# UTIF.js
A small, fast and advanced TIFF / EXIF (+ DNG, CR2, NEF and other TIFF-ish files) decoder and encoder. It is the main TIFF library for [Photopea image editor](https://www.photopea.com). Try to open your TIFF file with Photopea to see, if UTIF.js can parse it.

* Supports Black & White, Grayscale, RGB and Paletted images
* Supports Fax 3 and Fax 4 (CCITT), JPEG, LZW, PackBits and other compressions (1,3,4,5,6,7,8,32773,32809)
* E.g. [this 8 MPix image](//www.photopea.com/api/img/G4.TIF) with Fax 4 compression is just 56 kB ( [Open in Photopea](https://www.photopea.com?p=%7B%22files%22:%5B%22//www.photopea.com/api/img/G4.TIF%22%5D%7D) )

For RAW files, UTIF.js only decodes raw sensor data (and JPG previews, if there are any). It does not convert the raw data into a displayable image (RGBA). Such conversion is complex and out of scope of this library.

## Installation

Download and include the `UTIF.js` file in your code. If you're in NodeJS or otherwise using NPM, run:

```sh
npm install utif
```

#### `UTIF.decode(buffer)`
* `buffer`: ArrayBuffer containing TIFF or EXIF data
* returns an array of "IFDs" (image file directories). Each IFD is an object, keys are "tXYZ" (XYZ is a TIFF tag number), values are values of these tags. You can get the the dimension (and other properties, "metadata") of the image without decompressing pixel data.

#### `UTIF.decodeImage(buffer, ifd)`
* `buffer`: ArrayBuffer containing TIFF or EXIF data
* `ifd`: the element of the output of UTIF.decode()
* If there is an image inside the IFD, it is decoded and three new properties are added to the IFD:
* * `width`: the width of the image
* * `height`: the height of the image
* * `data`: decompressed pixel data of the image

TIFF files may have various number of channels and various color depth. The interpretation of `data` depends on many tags (see the [TIFF 6 specification](http://www.npes.org/pdf/TIFF-v6.pdf)). The following function converts any TIFF image into a 8-bit RGBA image.

#### `UTIF.toRGBA8(ifd)`
* `ifd`: image file directory (element of "ifds" returned by UTIF.decode(), processed by UTIF.decodeImage())
* returns Uint8Array of the image in RGBA format, 8 bits per channel (ready to use in context2d.putImageData() etc.)

### Example

```javascript
function imgLoaded(e) {
  var ifds = UTIF.decode(e.target.response);
  UTIF.decodeImage(e.target.response, ifds[0])
  var rgba  = UTIF.toRGBA8(ifds[0]);  // Uint8Array with RGBA pixels
  console.log(ifds[0].width, ifds[0].height, ifds[0]);
}

var xhr = new XMLHttpRequest();
xhr.open("GET", "my_image.tif");
xhr.responseType = "arraybuffer";
xhr.onload = imgLoaded;   xhr.send();
```
## Use TIFF images in HTML

If you are not a programmer, you can use TIFF images directly inside the `<img>` element of HTML. Then, it is enough to call `UTIF.replaceIMG()` once at some point.

#### `UTIF.replaceIMG()`
```html
<body onload="UTIF.replaceIMG()">
...
<img src="image.tif" />  <img src="dog.tif" /> ...
```
And UTIF.js will do the rest. Internally, the "src" attribute of the image will be replaced with a new URI of the image (base64-encoded PNG). Note, that you can also insert DNG, CR2, NEF and other raw images into HTML this way.

## Encoding TIFF images

You should not save images into TIFF format in the 21st century. Save them as PNG instead (e.g. using [UPNG.js](https://github.com/photopea/UPNG.js)). If you still want to use TIFF format for some reason, here it is.

#### `UTIF.encodeImage(rgba, w, h, metadata)`
* `rgba`: ArrayBuffer containing RGBA pixel data
* `w`: image width
* `h`: image height
* `metadata` [optional]: IFD object (see below)
* returns ArrayBuffer of the binary TIFF file. No compression right now.

#### `UTIF.encode(ifds)`
* `ifds`: array of IFDs (image file directories). An IFD is a JS object with properties "tXYZ" (where XYZ are TIFF tags)
* returns ArrayBuffer of binary data. You can use it to encode EXIF data.

## Dependencies
TIFF format sometimes uses Inflate algorithm for compression (but it is quite rare). Right now, UTIF.js calls [Pako.js](https://github.com/nodeca/pako) for the Inflate method.

---
_Source: https://npm.io/package/utif · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._