Calculate percentage of a face in an image
What Would the calculation of porcetangem of a face in an image look like? Suppose I have a 3x4 photo of a user, but he was with a good part of the hair capping his face. Would there be any way to detect that the image does not have a minimum com percentage of the user's face?
1 answers
Facial detection algorithms work from facial features. Thus, certain features must be present in the photo so that the algorithm can extract the necessary data and determine whether the object being evaluated is a face or not.
It is completely possible to have a high percentage of exposure of a face in the photo and yet detection fails if the right features are hidden / manipulated, such as the pose, facial expression, lighting, etc.
Therefore, thinking of the success of facial detection as if it depended on a minimum percentage of face exposure in the photo is not a realistic approach.
I recommend the article Eigenfaces vs Fishfaces, from Columbia University (1997), which discusses a more robust technique for solving these problems and makes an interesting comparison with the 2 most popular facial detection/recognition algorithms.