Thank you for your response. The link you described is something related to face tracking. Is it correct link? Sorry for not clear description, but if I use the following, I can get complete color video. var colorSpace = CGColorSpaceCreateDeviceRGB() var bitmapInfo = CGBitmapInfo(rawValue: (CGBitmapInfo.byteOrder32Little.rawValue | CGImageAlphaInfo.premultipliedFirst.rawValue) as UInt32) I just replace those 2 parameters with above-mentioned parameters to get greyscale video. I just wonder if this is correct way to get greyscale video , or I should use other way.

Thank you for your response. I understand I need to reload the cell to update its display.

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Yes, it is the same.

Well, it takes some time to modify my code. Before do that, please let me ask you the following question; "Is that the standard usage of Biometrics authentication to use a button action after back from background?"

I added a button and check if it works. The result is, I still see the problem.