/// <summary>
/// detect faces on a picture and draw a square in each face
/// </summary>
private void detectFaces(){
//first check if picture has been taken
if(null != cameraBitmap){
//get width of a picture
int width = cameraBitmap.Width;
//get height of a picture
int height = cameraBitmap.Height;
//Initialize a facedetector with the picture dimensions and the max number of faces to check
FaceDetector detector = new FaceDetector(width, height, MainActivity.MAX_FACES);
//Create an array of faces with the number of max faces to check
Android.Media.FaceDetector.Face[] faces = new Android.Media.FaceDetector.Face[MainActivity.MAX_FACES];
//create a main bitmap
Bitmap bitmap565 = Bitmap.CreateBitmap(width, height, Bitmap.Config.Rgb565);
//create a dither paint
Paint ditherPaint = new Paint();
//create a draw paint
Paint drawPaint = new Paint();
//set true dither to dither paint variable
ditherPaint.Dither = true;
//set color red for the square
drawPaint.Color = Color.Red;
//set stroke to style
drawPaint.SetStyle(Paint.Style.Stroke);
//set stroke width
drawPaint.StrokeWidth = 2;
//Create a canvas
Canvas canvas = new Canvas();
//set bitmap to canvas
canvas.SetBitmap(bitmap565);
//draw bitmap to canvas
canvas.DrawBitmap(cameraBitmap, 0, 0, ditherPaint);
//get a number of faces detected
int facesFound = detector.FindFaces(bitmap565, faces);
//mid face point
PointF midPoint = new PointF();
//eye distance variable
float eyeDistance = 0.0f;
//confidence variable
float confidence = 0.0f;
//print numbre of faces found
System.Console.WriteLine ("Number of faces found: " + facesFound);
//check if found at least one face
if(facesFound > 0)
{
//for each face draw a red squeare
for(int index=0; index<facesFound; ++index){
// get midpoint of a face
faces[index].GetMidPoint(midPoint);
//get eye distance
eyeDistance = faces[index].EyesDistance();
//get confidence
confidence = faces [index].Confidence ();
//print all parameters
System.Console.WriteLine ("Confidence: " + confidence +
", Eye distance: " + eyeDistance +
", Mid Point: (" + midPoint.X + ", " + midPoint.Y + ")");
//draw a square in the picture
canvas.DrawRect((int)midPoint.X - eyeDistance ,
(int)midPoint.Y- eyeDistance ,
(int)midPoint.X + eyeDistance,
(int)midPoint.Y + eyeDistance, drawPaint);
}
}
//get imageview from layout
ImageView imageView = (ImageView)FindViewById(Resource.Id.image_view);
//set image with the red squares to imageview
imageView.SetImageBitmap(bitmap565);
}
}
protected override void OnSizeChanged (int w, int h, int oldw, int oldh)
{
int curW = mBitmap != null ? mBitmap.Width : 0;
int curH = mBitmap != null ? mBitmap.Height : 0;
if (curW >= w && curH >= h) {
return;
}
if (curW < w) curW = w;
if (curH < h) curH = h;
var newBitmap = Bitmap.CreateBitmap (curW, curH, Bitmap.Config.Argb8888);
var newCanvas = new Canvas ();
newCanvas.SetBitmap (newBitmap);
if (mBitmap != null) {
newCanvas.DrawBitmap (mBitmap, 0, 0, null);
}
mBitmap = newBitmap;
mCanvas = newCanvas;
mFadeSteps = MAX_FADE_STEPS;
}