Object Detection on Edge of Equirectangular Image

THETA API Usage plugin
1

I tested the THETA Automatic Face Blur plug-in to see how accurate it is when the face is on the edge of the equirectangular image.

It performed very well.

Original Equirectangular Image Before Blur

image
image549×818 156 KB

image
image337×841 77.3 KB

Equirectangular with Successful Detection and Face Blurring

image
image468×580 104 KB

image

Close Up of Detection

image

Quartering Image

I don’t understand the technique, but this section appears to be relevant.

    //Cut both sides of the equirectangular picture which the size is a quarter of it.
    int trimmingWidth = (int) (mBitmapToDetectFace.getWidth() * 0.25);
    int trimmingHeight = mBitmapToDetectFace.getHeight();

    Bitmap leftTrimmingImage =
            Bitmap.createBitmap(mBitmapToDetectFace, 0, 0, trimmingWidth, trimmingHeight,
                    null, true);
    Bitmap rightTrimmingImage =
            Bitmap.createBitmap(mBitmapToDetectFace,
                    mBitmapToDetectFace.getWidth() - trimmingWidth, 0,
                    trimmingWidth, trimmingHeight, null, true);

    //Decide the size of composited bitmap.
    int compositeWidth = trimmingWidth * 2;
    int compositeHeight = trimmingHeight;
    //Composite the two cut bitmap.
    Bitmap compositedImage = Bitmap
            .createBitmap(compositeWidth, compositeHeight, Bitmap.Config.RGB_565);
    Canvas canvas = new Canvas(compositedImage);
    canvas.drawBitmap(mBitmapToDetectFace, 0, 0, null);
    canvas.drawBitmap(leftTrimmingImage, trimmingWidth, 0, null);
    canvas.drawBitmap(rightTrimmingImage, 0, 0, null);

With this type of detection, it seems possible to apply the TensorFlow learning models to THETA media. I’m not sure how this will work with video.