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| author | Wu-cheng Li <wuchengli@google.com> | 2011-11-15 06:14:11 -0800 |
|---|---|---|
| committer | Android (Google) Code Review <android-gerrit@google.com> | 2011-11-15 06:14:11 -0800 |
| commit | b90a70d1542edd5a95e73b75192e6eb5a66401cc (patch) | |
| tree | b40613693e6017e18fd76e7e9990d474586d6827 /core | |
| parent | 4b7494e07a44c0aa363379be463de70455a895f3 (diff) | |
| parent | 8c13670c13a7a965884d92193b039e26c96b95c6 (diff) | |
| download | frameworks_base-b90a70d1542edd5a95e73b75192e6eb5a66401cc.zip frameworks_base-b90a70d1542edd5a95e73b75192e6eb5a66401cc.tar.gz frameworks_base-b90a70d1542edd5a95e73b75192e6eb5a66401cc.tar.bz2 | |
Merge "Improve camera face detection javadoc." into ics-mr1
Diffstat (limited to 'core')
| -rw-r--r-- | core/java/android/hardware/Camera.java | 43 |
1 files changed, 36 insertions, 7 deletions
diff --git a/core/java/android/hardware/Camera.java b/core/java/android/hardware/Camera.java index 3becec0..c2a757f 100644 --- a/core/java/android/hardware/Camera.java +++ b/core/java/android/hardware/Camera.java @@ -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() */ |