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Merge "Improve camera face detection javadoc." into ics-mr1

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Wu-cheng Li
2011-11-15 06:14:11 -08:00
committed by Android (Google) Code Review
parent 4b7494e07a 8c13670c13
commit b90a70d154
1 changed files with 36 additions and 7 deletions
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43
core/java/android/hardware/Camera.java
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@@ -1111,9 +1111,21 @@ public class Camera {
* Parameters#getMaxNumDetectedFaces()} returns a number larger than 0.
* If the face detection has started, apps should not call this again.
*
* When the face detection is running, {@link Parameters#setWhiteBalance(String)},
* <p>When the face detection is running, {@link Parameters#setWhiteBalance(String)},
* {@link Parameters#setFocusAreas(List)}, and {@link Parameters#setMeteringAreas(List)}
* have no effect.
* have no effect. The camera uses the detected faces to do auto-white balance,
* auto exposure, and autofocus.
*
* <p>If the apps call {@link #autoFocus(AutoFocusCallback)}, the camera
* will stop sending face callbacks. The last face callback indicates the
* areas used to do autofocus. After focus completes, face detection will
* resume sending face callbacks. If the apps call {@link
* #cancelAutoFocus()}, the face callbacks will also resume.</p>
*
* <p>After calling {@link #takePicture(Camera.ShutterCallback, Camera.PictureCallback,
* Camera.PictureCallback)} or {@link #stopPreview()}, and then resuming
* preview with {@link #startPreview()}, the apps should call this method
* again to resume face detection.</p>
*
* @throws IllegalArgumentException if the face detection is unsupported.
* @throws RuntimeException if the method fails or the face detection is
@@ -1163,14 +1175,31 @@ public class Camera {
* camera field of view, and (1000, 1000) represents the bottom-right of
* the field of view. For example, suppose the size of the viewfinder UI
* is 800x480. The rect passed from the driver is (-1000, -1000, 0, 0).
* The corresponding viewfinder rect should be (0, 0, 400, 240). The
* width and height of the rect will not be 0 or negative. The
* coordinates can be smaller than -1000 or bigger than 1000. But at
* least one vertex will be within (-1000, -1000) and (1000, 1000).
* The corresponding viewfinder rect should be (0, 0, 400, 240). It is
* guaranteed left < right and top < bottom. The coordinates can be
* smaller than -1000 or bigger than 1000. But at least one vertex will
* be within (-1000, -1000) and (1000, 1000).
*
* <p>The direction is relative to the sensor orientation, that is, what
* the sensor sees. The direction is not affected by the rotation or
* mirroring of {@link #setDisplayOrientation(int)}.</p>
* mirroring of {@link #setDisplayOrientation(int)}. The face bounding
* rectangle does not provide any information about face orientation.</p>
*
* <p>Here is the matrix to convert driver coordinates to View coordinates
* in pixels.</p>
* <pre>
* Matrix matrix = new Matrix();
* CameraInfo info = CameraHolder.instance().getCameraInfo()[cameraId];
* // Need mirror for front camera.
* boolean mirror = (info.facing == CameraInfo.CAMERA_FACING_FRONT);
* matrix.setScale(mirror ? -1 : 1, 1);
* // This is the value for android.hardware.Camera.setDisplayOrientation.
* matrix.postRotate(displayOrientation);
* // Camera driver coordinates range from (-1000, -1000) to (1000, 1000).
* // UI coordinates range from (0, 0) to (width, height).
* matrix.postScale(view.getWidth() / 2000f, view.getHeight() / 2000f);
* matrix.postTranslate(view.getWidth() / 2f, view.getHeight() / 2f);
* </pre>
*
* @see #startFaceDetection()
*/