Show coordinated for each keypoints using flandmark (Javacv)

Question

I am currently using this example from flandmark using JavaCV. Refer to: https://github.com/bytedeco/javacv-examples/blob/master/flandmark-demo/src/main/java/flandmark/Example1.java . I managed to run the code but is there a way that I could display the coordinated of each of the key point from the face (eye, mouth, nose)? There are around 7/8 key points that could be detected by the flandmark library. Thanks.

Answer 1

You find landmarks in function detectFaceInImage . At the bottom of the same function you see how to draw the detected landmarks on the face:

flandmark_detect(input, bbox, model, landmarks);

// display landmarks
cvRectangle(orig, cvPoint(bbox[0], bbox[1]), cvPoint(bbox[2], bbox[3]), CV_RGB(255, 0, 0));
cvRectangle(orig,
cvPoint((int) model.bb().get(0), (int) model.bb().get(1)),
cvPoint((int) model.bb().get(2), (int) model.bb().get(3)), CV_RGB(0, 0, 255));
cvCircle(orig,
cvPoint((int) landmarks[0], (int) landmarks[1]), 3, CV_RGB(0, 0, 255), CV_FILLED, 8, 0);
for (int i = 2; i < 2 * model.data().options().M(); i += 2) {
    cvCircle(orig, cvPoint((int) (landmarks[i]), (int) (landmarks[i + 1])), 3, CV_RGB(255, 0, 0), CV_FILLED, 8, 0);
}

bbox is a int[] containing the coordinates of the face bounding box as:

int[0] -> top left x
int[1] -> top left y
int[2] -> bottom right x
int[3] -> bottom right y

landmarks is a double[] , containing the coordinates of the points of the landmark in sequence:

index: 0   1   2   3   ...
coord: s0x s0y s1x s1y ...

with reference to the image from the flandmark homepage

The total number of landmarks is stored in model.data().options().M() . Now you have all the basics to print the coordinates of the landmarks:

for (int i = 0; i < 2 * model.data().options().M(); i += 2) {
    System.out.println("S" + (i/2) + ": (" + (int)(landmarks[i]) + ", " + (int)(landmarks[i+1]) + ")");
}