CameraHal: Add filter to smooth faces from OMXCamera

Filter faces coming from Ducati to smooth out the jitter.
This patch requires the face tracking mechanism in Ducati
so faces are ordered properly for each frame. Also, this patch
is only providing filtering of face sizes since Ducati is already
smoothing the face positions.

b/5141268

Change-Id: Ia7ee1c46ca41fcdd1e45505242f2802b0b4fb647
Orginal-author: Mandeep Kumar <mandeep@ti.com>
Signed-off-by: Tyler Luu <tluu@ti.com>

2 files changed, 79 insertions, 20 deletions

diff --git a/camera/OMXCameraAdapter/OMXDefaults.cpp b/camera/OMXCameraAdapter/OMXDefaults.cpp
index 57ee556..9157d06 100644
--- a/camera/OMXCameraAdapter/OMXDefaults.cpp
+++ b/camera/OMXCameraAdapter/OMXDefaults.cpp
@@ -29,6 +29,8 @@ namespace android {
 #undef LOG_TAG
 #define LOG_TAG "CameraHAL"
 
+#define __STRINGIFY(s) __STRING(s)
+
 // OMX Camera defaults
 const char OMXCameraAdapter::DEFAULT_ANTIBANDING[] = "auto";
 const char OMXCameraAdapter::DEFAULT_BRIGHTNESS[] = "50";
@@ -62,7 +64,7 @@ const char OMXCameraAdapter::DEFAULT_SHARPNESS[] = "100";
 const char OMXCameraAdapter::DEFAULT_VSTAB[] = "0";
 const char OMXCameraAdapter::DEFAULT_WB[] = "auto";
 const char OMXCameraAdapter::DEFAULT_ZOOM[] = "0";
-const char OMXCameraAdapter::DEFAULT_MAX_FD_HW_FACES[] = "35";
+const char OMXCameraAdapter::DEFAULT_MAX_FD_HW_FACES[] = __STRINGIFY(MAX_NUM_FACES_SUPPORTED);
 const char OMXCameraAdapter::DEFAULT_MAX_FD_SW_FACES[] = "0";
 const char OMXCameraAdapter::DEFAULT_FOCAL_LENGTH[] = "4.6";
 const char OMXCameraAdapter::DEFAULT_HOR_ANGLE[] = "54.8";
diff --git a/camera/OMXCameraAdapter/OMXFD.cpp b/camera/OMXCameraAdapter/OMXFD.cpp
index 2900d68..3c0b219 100644
--- a/camera/OMXCameraAdapter/OMXFD.cpp
+++ b/camera/OMXCameraAdapter/OMXFD.cpp
@@ -30,6 +30,13 @@
 
 #define FACE_DETECTION_THRESHOLD 80
 
+// constants used for face smooth filtering
+static const int HorizontalFilterThreshold = 40;
+static const int VerticalFilterThreshold = 40;
+static const int HorizontalFaceSizeThreshold = 30;
+static const int VerticalFaceSizeThreshold = 30;
+
+
 namespace android {
 
 status_t OMXCameraAdapter::setParametersFD(const CameraParameters &params,
@@ -61,12 +68,11 @@ status_t OMXCameraAdapter::startFaceDetection()
         goto out;
     }
 
+    // Note: White balance will not be face prioritized, since
+    // the algorithm needs full frame statistics, and not face
+    // regions alone.
 
-    //Note: White balance will not be face prioritized, since
-    //the algorithm needs full frame statistics, and not face
-    //regions alone.
-
-
+    faceDetectionNumFacesLastOutput = 0;
  out:
     return ret;
 }
@@ -95,6 +101,7 @@ status_t OMXCameraAdapter::stopFaceDetection()
         apply3Asettings(mParameters3A);
     }
 
+    faceDetectionNumFacesLastOutput = 0;
  out:
     return ret;
 }
@@ -105,6 +112,7 @@ void OMXCameraAdapter::pauseFaceDetection(bool pause)
     // pausing will only take affect if fd is already running
     if (mFaceDetectionRunning) {
         mFaceDetectionPaused = pause;
+        faceDetectionNumFacesLastOutput = 0;
     }
 }
 
@@ -125,7 +133,7 @@ status_t OMXCameraAdapter::setFaceDetection(bool enable, OMX_U32 orientation)
 
     if ( NO_ERROR == ret )
         {
-        if ( orientation < 0 || orientation > 270 ) {
+        if ( orientation > 270 ) {
             orientation = 0;
         }
 
@@ -368,6 +376,20 @@ status_t OMXCameraAdapter::encodeFaceCoordinates(const OMX_FACEDETECTIONTYPE *fa
         / *               (r, b)
           */
 
+        if (mDeviceOrientation == 180) {
+            orient_mult = -1;
+            trans_left = 2; // right is now left
+            trans_top = 3; // bottom is now top
+            trans_right = 0; // left is now right
+            trans_bot = 1; // top is not bottom
+        } else {
+            orient_mult = 1;
+            trans_left = 0; // left
+            trans_top = 1; // top
+            trans_right = 2; // right
+            trans_bot = 3; // bottom
+        }
+
         int j = 0, i = 0;
         for ( ; j < faceData->ulFaceCount ; j++)
             {
@@ -382,23 +404,12 @@ status_t OMXCameraAdapter::encodeFaceCoordinates(const OMX_FACEDETECTIONTYPE *fa
              continue;
 
             if (mDeviceOrientation == 180) {
-                orient_mult = -1;
-                trans_left = 2; // right is now left
-                trans_top = 3; // bottom is now top
-                trans_right = 0; // left is now right
-                trans_bot = 1; // top is not bottom
                 // from sensor pov, the left pos is the right corner of the face in pov of frame
-                nLeft  = faceData->tFacePosition[j].nLeft + faceData->tFacePosition[j].nWidth;
+                nLeft = faceData->tFacePosition[j].nLeft + faceData->tFacePosition[j].nWidth;
                 nTop =  faceData->tFacePosition[j].nTop + faceData->tFacePosition[j].nHeight;
             } else {
-                orient_mult = 1;
-                trans_left = 0; // left
-                trans_top = 1; // top
-                trans_right = 2; // right
-                trans_bot = 3; // bottom
-                nLeft  = faceData->tFacePosition[j].nLeft;
+                nLeft = faceData->tFacePosition[j].nLeft;
                 nTop =  faceData->tFacePosition[j].nTop;
-
             }
 
             tmp = ( double ) nLeft / ( double ) previewWidth;
@@ -435,6 +446,52 @@ status_t OMXCameraAdapter::encodeFaceCoordinates(const OMX_FACEDETECTIONTYPE *fa
         faceResult->number_of_faces = i;
         faceResult->faces = faces;
 
+        for (int i = 0; i  < faceResult->number_of_faces; i++)
+        {
+            int centerX = (faces[i].rect[trans_left] + faces[i].rect[trans_right] ) / 2;
+            int centerY = (faces[i].rect[trans_top] + faces[i].rect[trans_bot] ) / 2;
+
+            int sizeX = (faces[i].rect[trans_right] - faces[i].rect[trans_left] ) ;
+            int sizeY = (faces[i].rect[trans_bot] - faces[i].rect[trans_top] ) ;
+
+            for (int j = 0; j < faceDetectionNumFacesLastOutput; j++)
+            {
+                int tempCenterX = (faceDetectionLastOutput[j].rect[trans_left] +
+                                  faceDetectionLastOutput[j].rect[trans_right] ) / 2;
+                int tempCenterY = (faceDetectionLastOutput[j].rect[trans_top] +
+                                  faceDetectionLastOutput[j].rect[trans_bot] ) / 2;
+                int tempSizeX = (faceDetectionLastOutput[j].rect[trans_right] -
+                                faceDetectionLastOutput[j].rect[trans_left] ) ;
+                int tempSizeY = (faceDetectionLastOutput[j].rect[trans_bot] -
+                                faceDetectionLastOutput[j].rect[trans_top] ) ;
+
+                if ( (abs(tempCenterX - centerX) < HorizontalFilterThreshold) &&
+                     (abs(tempCenterY - centerY) < VerticalFilterThreshold) )
+                {
+                    // Found Face. It did not move too far.
+                    // Now check size of rectangle compare to last output
+                    if ( (abs (tempSizeX -sizeX) < HorizontalFaceSizeThreshold) &&
+                         (abs (tempSizeY -sizeY) < VerticalFaceSizeThreshold) )
+                    {
+                        // Rectangle is almost same as last time
+                        // Output exactly what was done for this face last time.
+                        faces[i] = faceDetectionLastOutput[j];
+                    }
+                    else
+                    {
+                        // TODO(XXX): Rectangle size changed but position is same.
+                        // Possibly we can apply just positional correctness.
+                    }
+                }
+            }
+        }
+
+        // Save this output for next iteration
+        for (int i = 0; i  < faceResult->number_of_faces; i++)
+        {
+            faceDetectionLastOutput[i] = faces[i];
+        }
+        faceDetectionNumFacesLastOutput = faceResult->number_of_faces;
     } else {
         faceResult->number_of_faces = 0;
         faceResult->faces = NULL;