mozilla

CameraControl.setExposureCompensation()

Non-standard
This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.

This API is available on Firefox OS for privileged or certified applications only.

Summary

This method is used to change the exposure compensation value.

Acceptable values for the exposure compensation range from the CameraCapabilities.minExposureCompensation value to the CameraCapabilities.maxExposureCompensation value in steps equal to the value of CameraCapabilities.stepExposureCompensation; invalid values will be rounded to the nearest valid value.

Syntax

CameraControl.setExposureCompensation([compensation]);

Parameters

compensation Optional
The new value for the exposure compensation. This parameter is optional; if it's missing, the camera will use automatic exposure compensation.

Example

This example gets the first camera and sets the exposure compensation to the middle of the allowed range.

var options  = {
  camera: navigator.mozCameras.getListOfCameras()[0]
};
 
function onAccessCamera( camera ) {
  var min  = camera.capabilities.minExposureCompensation;
  var max  = camera.capabilities.maxExposureCompensation;
  var step = camera.capabilities.stepExposureCompensation;

  var mid  = Math.round((max - min) / step / 2) * step;

  camera.setExposureCompensation(mid);
};
 
navigator.mozCameras.getCamera(options, onAccessCamera);

Specification

Not part of any specification; however, this API should be removed when the WebRTC Capture and Stream API has been implemented.

See also

Document Tags and Contributors

Contributors to this page: Sheppy, Jeremie, teoli, chrisdavidmills, kscarfone, ajaybhat
Last updated by: chrisdavidmills,