This web element can be used to tag videos, frame by frame. It is useful for video-processing applications, where computer vision algorithms are used on video input. For example, drones and robot applications are used to track a specific persn, to detect oil pipes leaks, etc.

Using the video-tagging web wlement, users can mark regions in each frame and associate text tags to these regions.

The video-tagging web element is built using HTML5, CSS3 based on Polymer. Here's an example of marking rectangualr regions in a frame and tagging them with textual labels, representing the objects within the region. More details on the functionality apear below.

The area selection is credited to ImageAreaSelect

Follow the next steps to run the demo locally.

• You will need the following installations to be able to run the demo:
  node.js
  Bower
  Git client or GitHub app

• Clone the repository and install required packages

   // clone the repository
   git clone https://github.com/CatalystCode/video-tagging.git
  

   // change dir to the 'demo'
   cd video-tagging
  

   // install required node.js packages
   npm install
  

   // install http-server to be able to host the demo
   npm install -g http-server
  

   // install bower components
   cd demo
   bower install
  

   // run a local http-server to host the demo
   http-server
  

• Open your browser: http://localhost:8080/index.html

• Select a tagging job from the list

• Use the mouse to mark a frame point/rectangle and use the tags toggles to select the relevant tags

In order to use the element in your app, you need to install the video-tagging Bower component as follows:

 bower install CatalystCode/video-tagging

In your HTML page, add the element as follows:

• Add a reference to the element:

    <link rel="import" href="/bower_components/video-tagging/video-tagging.html">
  

• Add the element tag inline:

   <div style="width:65%">
   	<video-tagging id='video-tagging'></video-tagging>
   </div>
  

A video-tagging web app, using this web element, is available here: VideoTaggingTool

##API & Usage

The video-tagging element is based on a video player, with additional functionality for tagging the frames. The tags are text labels associated to regions or points designated in each frame. The regions that are currently supported are of type "Rectangle".

A video-tagging job is an input video and a configuration object which defines the tagging job. Here's an example of a job configuration:

{ "id": 5,
  "video": "sample-video.mp4",
  "Description = "human tracking job",
  "regiontype":"Point", 
  "regionsize":"25", 
  "multiregions":"1", // allow multiple regions per frame
  "tage" : ["text-1","text-2","text-3"],
  "DurationSeconds" = 21.8, 
  "FramesPerSecond = 25,
  "Height" = 480,
  "Width" = 640
}

Each frame may have multiple region/point markers, each labeled with text tags.

Example #1: Point markers

{ region: { name: 1, type: 'Point', x1: 123, y1: 54, tags: [ 'horse', 'brown'], ... }}

Example #2: rectangle markers

{ region: { name: 1, type: 'Rectangle', x1: 123, y1: 54, x2: 35, y2: 78, tags: [ 'horse', 'brown'], ... }}

###Video Controls:

1. Video timebar
2. Previous frame
3. Play/Pause
4. Next frame
5. Skip to the furst untagged frame
6. Frame index
7. Play speed
8. Timer
9. Volume/Mute

###Tagging controls

1. Tags - click on the relevant buttons to tag the selected region/point in the frame.
2. Mark as empty frame - designates a frame with no relevant tags.
3. Lock tags - automatically adds selected tags to new regions. Toggle to enable/disable.

###Tag the video

Point marker
click on the frame and associate tags to the clicked point/position in the frame.

Rectangle marker Click on the frame, drag mouse to create a rectangle and release the mouse. Add tags using the tag toggles.

To edit tags, select a marker (Point or Rectangle), and add/remove tags.

Lock tags When enabled, the selected tags will remain selected after tagging the current frame and moving to the next frame. When only single marker can be tagged in a frame ("multitags="0") and the tags are locked, the frame will advance automatically after the marker was created. In tsuch case, the tagging workflow is as follows:

1. Create a new region - Click or drag
2. Select tags
3. Click on the Lock Icon
4. Create a region
5. Repeat
6. Click the icon again to exit this mode.

####Input Data
The following properties must be populated:

• videoduration - number, for example 30.07
• videowidth - number, for example 420
• videoheight - number, for example 240
• framerate - number, for example 29.97
• regiontype - string, can be "point" or "rectangle"
• regionsize - number, for example 20 (in pixels) for point regions.
• multitags - string, can be "0" or "1"
• inputtagsarray - a string array of the possible tags
• inputFrames - an object containing all the tagged frames of this video (That have been created at an earlier time). The object is a dictionary, the frame number is the key. Each frame has a collection of regions and each region has a collection of tags.
  In this example we see data for frames 434, 442 and 628.
  
  Expanded- each region is an object with coordinates and a tags array.
  

Example:

var videotagging = document.getElementById('video-tagging');
		
videotagging.videoduration = data.video.DurationSeconds;
videotagging.videowidth = data.video.Width;
videotagging.videoheight = data.video.Height;
videotagging.framerate = data.video.FramesPerSecond;

Finally, to load the control, set the src property to the URL of the video:

videotagging.src = data.video.Url;

####Output Data
When a region is created or updated and when tags are added/removed, the element fires an event called "onregionchanged". Register to this event to get the data:

document.getElementById('video-tegging').addEventListener('onregionchanged', function (e) {...

The control returns all the regions and their tags in the current frame. The parameter e holds this data in e.detail:

####Browser Support

Chrome 47
Firefox 43

It is recommended to use the same browser consistently as there are differences between them regarding video time calculations. Better precision was observed in Firefox.

MIT