# PDFAnno
PDFAnno is a browser-based linguistic annotation tool for PDF documents.
It offers functions for annotating PDF with labels and relations.
For natural language processing and machine learning, it is suitable for development of gold-standard data with named entity spans, dependency relations, and coreference chains.
* [Online Demo (v0.3.0)](https://paperai.github.io/pdfanno/0.3.0/)
* [Online Demo (latest)](https://paperai.github.io/pdfanno/latest/)
**It is highly recommended to use the latest version of Chrome.** (Firefox will also be supported in future.)
If you install PDFAnno locally,
```
git clone https://github.com/paperai/pdfanno.git
cd pdfanno
npm install
```
or
```
npm install pdfanno
```
See the developer's guide for more details.
## Usage
1. Visit the [online demo](https://paperai.github.io/pdfanno/latest/) with the latest version of Chrome.
1. Load your PDF and annotation file (if any). Sample PDFs and annotations are downloadable from [here](https://cl.naist.jp/%7Eshindo/pdfanno_material.zip).
* For PDFs located on your computer:
Put the PDFs and annotation files (if any) in the same directory, then specify the directory via `Browse` button.
* For PDF available on the Web:
Access 'https://paperai.github.io/pdfanno/latest/?pdf=' + ``
For example, https://paperai.github.io/pdfanno/latest/?pdf=http://www.aclweb.org/anthology/P12-1046.pdf.
1. Annotate the PDF as you like.
1. Save your annotations via 
button.
If you continue the annotation, respecify your directory via `Browse` button to reload the PDF and anno file.
For security reasons, PDFAnno does NOT automatically save your annotations.
Don't forget to download your current annotations!
## Annotation Tools
| Icon | Description |
|:---:|:---:|
| 
| Span highlighting. It is disallowed to cross page boundaries. |
| 
| One-way relation. This is used for annotating dependency relation between spans. |
| 
| Two-way relation. |
| 
| Link relation. If you want to add non-directional relation between spans, use this. |
| 
| Rectangle. It is disallowed to cross page boundaries. |
## Annotation File (.anno)
In PDFAnno, the annotation file (.anno) follows [TOML](https://github.com/toml-lang/toml) format.
Here is an example of anno file:
```
version = 0.3
[1]
type = "span"
page = 1
position = [["95.818", "252.977", "181.761", "10.909"], ["95.818", "264.806", "107.136", "10.909"]]
label = "label-1"
[2]
type = "span"
page = 1
position = [["323.863", "230.715", "213.988", "11.590"], ["313.125", "244.522", "224.829", "10.795"]]
label = "label-2"
[3]
type = "rect"
page = 1
position = ["323.863", "230.715", "213.988", "11.590"]
label = "label-3"
[4]
type = "relation"
dir = "two-way"
ids = ["1", "2"]
label = "label-4"
```
where `position` indicates `(x, y, width, height)` of the annotation.
## Reference Anno File
To support multi-user annotation, PDFAnno allows to load `reference anno file`.
For example, if you create `a.anno` and an another annotator creates `b.anno` for the same PDF, load `a.anno` as usual, and load `b.anno` as a reference file. Then PDFAnno renders `a.anno` and `b.anno` with different colors each other. Rendering more than one reference file is also supported.
This is useful to check inter-annotator agreement and resolving annotation conflicts.
Note that the reference files are rendered as read-only.
## Annotation API
`PDFAnno` provides annotation API.
### Span
```
var span = new SpanAnnotation({
page: 1,
position:
[["139.03536681054345","60.237086766202694","155.97302418023767","14.366197183098592"]],
label: 'orange',
text: 'Ready?',
id: 1
});
window.add(span);
window.delete(span);
```
### Relation
```
var rel = new RelationAnnotation({
dir: 'link',
ids: ["1","2"],
label: 'sample'
});
window.add(rel);
window.delete(rel);
```
### Rectangle
```
var rect = new RectAnnotation({
page:1,
position:["9.24324324324326","435.94054054054055","235.7027027027027","44.65945945945946"],
label: 'rect-label',
id: 2
});
window.add(rect);
window.delete(rect);
```
### Read from TOML or JSON
```
var toml = `
version = 0.2
[1]
type = "span"
page = 1
position = [["139.03536681054345","60.237086766202694","155.97302418023767","14.366197183098592"]]
label = "orange"
text = "Ready?"
`;
var anno = readTOML(toml);
var annoObj = window.addAll(anno);
window.delete(annoObj["1"]);
// delete all annotations
window.clear();
```
## Developer's Guide
PDFAnno is built upon [pdf.js](https://github.com/mozilla/pdf.js) for PDF viewer.
We implement custom layers for rendering annotations on pdf.js.
### Install and Build
First, install [Node.js](https://nodejs.org/) and npm. The version of Node.js must be 6+.
Then, run the following commands:
```
npm install
npm run publish:latest
```
where the output is on `docs/latest`, and you can access PDFAnno via `docs/latest/index.html`.
For developing,
```
npm run dev
```
This command starts Webpack Dev Server and you can access [http://localhost:8080/dist/index.html](http://localhost:8080/dist/index.html) in your browser.
## Authors
* [hshindo](https://github.com/hshindo)
* [yoheiMune](https://github.com/yoheiMune)
## LICENSE
MIT