No faces found

[yigitbacakoglu]

• face_recognition version: latest
• Python version: 3.4
• Operating System: macos sierra

Description

The picture was taken with iphone8,
Library says 'no face found' on this image.

Dimensions: 2320 × 3088px

But when I capture a screenshot on mac, this works well.
Dimensions: 908x1218px

What I Did

face_recognition ./known/ ./unknown/group.jpg
WARNING: No faces found in ./known/yigit3.jpg. Ignoring file.

Is it possible to consider ExifTags and rotate the picture if required in the library?

[ageitgey]

You have to implement EXIF rotation yourself. If you Google, there are some python examples on stack overflow that work fine. I'd like to create a simple EXIF rotation python library sometime and add that feature here, but I haven't had time yet.

[DanielReyesDev]

@yigitbacakoglu Hey I'm developing an iOS App and a Backend server that use Django and face_recognition. So yesterday I realized about this problem with iOS cameras in general and I came with a solution about processing the Image in my iOS App before send it to server. More info here: https://stackoverflow.com/questions/10600613/ios-image-orientation-has-strange-behavior. So yes, it's an issue about iOS Cameras and you have to pre-process the image before pass it to face_recognition, but that's not an issue of face_recognition itself.
In swift I applied this method over the UIImage before send it to my backend and now It works as expected.

extension UIImage {
    func correctlyOrientedImage() -> UIImage {
        if self.imageOrientation == .up {
            return self
        }

        UIGraphicsBeginImageContextWithOptions(size, false, scale)
        draw(in: CGRect(x: 0, y: 0, width: size.width, height: size.height))
        let normalizedImage = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return normalizedImage ?? self
    }
}

[rom1504]

I just had this problem too. I took a few images from my google photos without thinking about this because google photos (and a lot of image displaying tools) auto rotate the images based on the exif, so you don't see the rotation.
I understand it takes a bit of time to add this to the library, but could you just add a notice in the README for now ?
So people don't get confused about getting poor results because of this problem.

Thank you for creating that really easy to use lib !

[ageitgey]

@rom1504 Thanks, that's a good idea. I'll do that.

[ageitgey]

I added it here: https://github.com/ageitgey/face_recognition/wiki/Common-Errors

[rom1504]

for information, here is a way to rotate your images in python before using face_recognition https://github.com/hooram/ownphotos/blob/29e4fa855363e00fb2168cfa706ef870e23013e0/api/models.py#L254

[YubinXie]

I also notice that the package is bad at detecting rotated faces, while can be very common in real life. Is this because no rotation augmentation added during training?