image.libfacedetection fails with some images about image HOT 4 CLOSED

Doc says: it can detect faces of dimension 48x48. Do the faces that you indicate have at least that size? Output also show a confidence called neighbours. You can use that according to your needs.
FYI. Model was trained on data from http://mmlab.ie.cuhk.edu.hk/projects/WIDERFace, caffe convolutional neural architecture is here: https://github.com/ShiqiYu/libfacedetection/tree/master/models/caffe

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I saw that, and If you look at the URL in the code, the face is bigger than that. Just so it is clear, I am including a manually cut rectangle of 94 x 79 pixels, containing the face.

Tested with a photo with people with different ethnicities from Peru and it also failed. Might it be a training bias?

Will check the source materials for the model next weekend and report back if I get a hint of what's happening.

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this face is 45x62 - why don't you take larger faces.

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OK, you were correct. Sorry for that. High-res versions do work.

from image.