ImageTracker
A tracker that tracks images in a video. Images are tracked using templates known as reference images.
Instantiation
AR.Tracker.Image
AR.Tracker.Image(options: object): ImageTracker
Instantiate an image tracker with the specified options.
Since: 0.4.0
Arguments
options: object, optional. An object with the following keys (all are optional):resolution: Resolution. The resolution of the tracker. Make sure that the resolution of the video is at least as high as this. Suggested values:"sm","sm+","md","md+".
Returns
A new image tracker.
Example
AR.Tracker.ImageTracker
AR.Tracker.ImageTracker(): ImageTracker
Instantiate an image tracker with the default settings.
Deprecated since: 0.4.0. Use AR.Tracker.Image() instead.
Returns
A new image tracker.
Properties
type
tracker.type: string, read-only
The string "image-tracker".
state
tracker.state: string, read-only
The current state of the tracker.
database
tracker.database: ReferenceImageDatabase, read-only
A database of reference images.
resolution
tracker.resolution: Resolution, read-only
The resolution adopted by the computer vision algorithms implemented in the tracker. Higher resolutions improve the tracking quality, but are computationally more expensive. Note that this resolution is different from, and should not be larger than, the resolution of the camera!
Note: this property is read-only since 0.4.0. Set the resolution when instantiating the tracker.
Events
An ImageTracker is an AREventTarget. You can listen to the following events:
targetfound
A target has been found.
Properties
referenceImage: ReferenceImage. The reference image that is linked to the target.
Example
tracker.addEventListener('targetfound', event => {
console.log('Found target: ' + event.referenceImage.name);
});
targetlost
A target has been lost.
Properties
referenceImage: ReferenceImage. The reference image that is linked to the target.