How do I setup an AVCaptureDevice and/or AVCaptureSession to support a wide range of lighting scenarios ("normal" top-lit by artificial lighting, sunlight from behind, sunlight from in front, etc.)?
The code I am currently using is giving me blackened images from a MacBookPro camera circa 2012 when the user is facing the camera with her back to a window the sun is shining through. I am using as much automatic settings for exposure and whitebalance as I can, and yet the problem is still occurring.
let session = AVCaptureSession()
session.beginConfiguration()
defer {
session.commitConfiguration()
}
if let videoDevice = AVCaptureDevice.default(for: AVMediaType.video) {
guard let videDeviceInput = try? AVCaptureDeviceInput(device: videoDevice), session.canAddInput(videoDeviceInput) else {
return
}
session.sessionPreset = .photo
do {
try videoDevice.lockForConfiguration()
if videoDevice.isExposureModeSupported(.continuousAutoExposure) {
videoDevice.exposureMode = .continuousAutoExposure
} else if videoDevice.isExposureModeSupported(.autoExposure) {
videoDevice.exposureMode = .autoExposure
} else {
NSLog("unable to set exposure mode")
}
if videoDevice.isWhiteBalanceModeSupported(.continuousAutoWhiteBalance) {
videoDevice.whiteBalanceMode = .continuousAutoWhiteBalance
} else if videoDevice.isWhiteBalanceModeSupported(.autoWhiteBalance) {
videoDevice.whiteBalanceMode = .autoWhiteBalance
} else {
NSLog("unable to set white balance mode")
}
let centerPoint = CGPoint(x:0.50, y:0.50)
if videoDevice.isExposurePointOfInterestSupported {
videoDevice.exposurePointOfInterest = centerPoint
}
if videoDevice.isFocusPointOfInterestSupported {
videoDevice.focusPointOfInterest = centerPoint
}
videoDevice.unlockForConfiguration()
} catch let error {
NSLog(error.localizedDescription)
}
session.addInput(videoDeviceInput)
let outputCapture = AVCaptureStillImageOutput()
guard session.canAddOutput(outputCapture) else {NSLog("unable to add output capture") ; return}
session.addOutput(outputCapture)
}My goal is to achieve the best possible image by telling the camera to automatically adjust all the parameters it can, like an old-school Canon AE-1 program used to back in the day.
