Some platforms or User Agents may provide built-in support for human + face lighting correction, in particular for camera video streams. + Web applications may either want to control or at least be aware that + human face lighting correction is applied at the source level. + This may for instance allow the web application to update its UI or to + not apply human face lighting correction on its own. + For that reason, we extend {{MediaStreamTrack}} with the following + properties. +
+The WebIDL changes are the following:
+partial dictionary MediaTrackSupportedConstraints {
+ boolean lightingCorrection = true;
+};
+
+partial dictionary MediaTrackCapabilities {
+ sequence<boolean> lightingCorrection;
+};
+
+partial dictionary MediaTrackConstraintSet {
+ ConstrainBoolean lightingCorrection;
+};
+
+partial dictionary MediaTrackSettings {
+ boolean lightingCorrection;
+};
+ When the "lightingCorrection" setting is set to true by
+ the ApplyConstraints algorithm, the UA will attempt to correct
+ human face and background lighting balance so that human faces are
+ not underexposed.
+
When the "lightingCorrection" setting is set to false by
+ the ApplyConstraints algorithm, the UA will not correct human
+ face and background lighting balance.
+
+<video></video>
+<script>
+// Open camera.
+const stream = await navigator.mediaDevices.getUserMedia({video: true});
+const [videoTrack] = stream.getVideoTracks();
+
+// Try to correct lighting.
+const videoCapabilities = videoTrack.getCapabilities();
+if ((videoCapabilities.lightingCorrection || []).includes(true)) {
+ await videoTrack.applyConstraints({lightingCorrection: {exact: true}});
+} else {
+ // Lighting correction is not supported by the platform or by the camera.
+ // Consider falling back to some other method.
+}
+
+// Show to user.
+const videoElement = document.querySelector("video");
+videoElement.srcObject = stream;
+</script>
+
+