MLKit Firebase android - How to convert FirebaseVisionFace to Image Object (like Bitmap)?
You created the FirebaseVisionImage
from a bitmap. After detection returns, each FirebaseVisionFace
describes a bounding box as a Rect
that you can use to extract the detected face from the original bitmap, e.g. using Bitmap.createBitmap().
Since the accepted answer was not specific enough I will try to explain what I did.
1.- Create an ImageView on LivePreviewActivity like this:
private ImageView imageViewTest;
2.- Create it on the Activity xml and link it to java file. I placed it right before the the sample code had, so it can be visible on top of the camera feed.
3.-When they create a FaceDetectionProcessor pass an instance of the imageView to be able to set the source image inside the object.
FaceDetectionProcessor processor = new FaceDetectionProcessor(imageViewTest);
4.-Change the constructor of FaceDetectionProcessor to be able to receive ImageView as a parameter and create a global variable that saves that instance.
public FaceDetectionProcessor(ImageView imageView) {
FirebaseVisionFaceDetectorOptions options =
new FirebaseVisionFaceDetectorOptions.Builder()
.setClassificationType(FirebaseVisionFaceDetectorOptions.ALL_CLASSIFICATIONS)
.setTrackingEnabled(true)
.build();
detector = FirebaseVision.getInstance().getVisionFaceDetector(options);
this.imageView = imageView;
}
5.- I created a crop method that takes a bitmap and a Rect to focus only on the face. So go ahead and do the same.
public static Bitmap cropBitmap(Bitmap bitmap, Rect rect) {
int w = rect.right - rect.left;
int h = rect.bottom - rect.top;
Bitmap ret = Bitmap.createBitmap(w, h, bitmap.getConfig());
Canvas canvas = new Canvas(ret);
canvas.drawBitmap(bitmap, -rect.left, -rect.top, null);
return ret;
}
6.- Modify detectInImage method to save an instance of the bitmap being detected and save it in a global variable.
@Override
protected Task<List<FirebaseVisionFace>> detectInImage(FirebaseVisionImage image) {
imageBitmap = image.getBitmapForDebugging();
return detector.detectInImage(image);
}
7.- Finally, modify OnSuccess method by calling the cropping method and assign result to the imageView.
@Override
protected void onSuccess(
@NonNull List<FirebaseVisionFace> faces,
@NonNull FrameMetadata frameMetadata,
@NonNull GraphicOverlay graphicOverlay) {
graphicOverlay.clear();
for (int i = 0; i < faces.size(); ++i) {
FirebaseVisionFace face = faces.get(i);
FaceGraphic faceGraphic = new FaceGraphic(graphicOverlay);
graphicOverlay.add(faceGraphic);
faceGraphic.updateFace(face, frameMetadata.getCameraFacing());
croppedImage = cropBitmap(imageBitmap, face.getBoundingBox());
}
imageView.setImageBitmap(croppedImage);
}