This API is available on Firefox OS for privileged or certified applications only.
Summary
The meteringAreas property is an Array of one or more Area objects that define where the camera will perform light metering.
If the array contains more objects than the number defined inside CameraCapabilities.maxMeteringAreas, extra objects will be ignored.
If set to null, the camera will determine the light metering areas by itself.
Area
Area objects are arbitrary JavaScript objects which describe an area of the sensor field. They are used in the Array presented by the meteringAreas property. Each object must have the following properties:
top- A number ranging from -1000 at the topmost of the sensor to 1000 at the bottommost of the sensor.
left- A number ranging from -1000 at the leftmost of the sensor to 1000 at the rightmost of the sensor.
bottom- A number ranging from -1000 at the topmost of the sensor to 1000 at the bottommost of the sensor.
right- A number ranging from -1000 at the leftmost of the sensor to 1000 at the rightmost of the sensor.
weight- A number defining the relative importance of the area against other areas, range from 0 to 1000.
Note: Objects missing one or more of these properties will be ignored.
Syntax
var areas = instanceOfCameraControl.meteringAreas
Value
Return an Array of one or more objects that define where the camera will perform light metering.
Example
var options = {
camera: navigator.mozCameras.getListOfCameras()[0]
};
function onSuccess( camera ) {
var max = camera.capabilities.maxMeteringAreas;
if (max > 0) {
camera.meteringAreas = [
{top: -500, bottom: 500, left: -500, right: 500, weight: 1000}
];
}
};
navigator.mozCameras.getCamera(options, onSuccess)
Specification
Not part of any specification; however, this API should be removed when the WebRTC Capture and Stream API has been implemented.