Reputation: 1647
AVFoundation brightness/exposure is different than the native camera. Is it possible to replicate the native camera settings with the AVFoundation framework?
Upvotes: 2
Views: 1678
Reputation: 4038
auto-exposure in Swift 4.2
// MARK: Exposure Methods
@objc
func tapToExpose(recognizer: UIGestureRecognizer){
if activeInput.device.isExposurePointOfInterestSupported{
let point = recognizer.location(in: camPreview)
// The tap location is converted from the `GestureRecognizer` to the preview's coordinates.
let pointOfInterest = previewLayer.captureDevicePointConverted(fromLayerPoint: point)
// Then , the second conversion is made for the coordinate space of the camera.
showMarkerAtPoint(point: point, marker: exposureMarker)
exposeAtPoint(pointOfInterest)
}
}
func exposeAtPoint(_ point: CGPoint){
let device = activeInput.device
if device.isExposurePointOfInterestSupported, device.isFocusModeSupported(.continuousAutoFocus){
do{
try device.lockForConfiguration()
device.exposurePointOfInterest = point
device.exposureMode = .continuousAutoExposure
if device.isFocusModeSupported(.locked){
// Now let us add the illumination for the `observeValueForKeyPath` method,
device.addObserver(self, forKeyPath: kExposure, options: .new, context: &adjustingExposureContext)
device.unlockForConfiguration()
}
}
catch{
print("Error Exposing on POI: \(String(describing: error.localizedDescription))")
}
}
}
// MARK: KVO
override func observeValue(forKeyPath keyPath: String?, of object: Any?, change: [NSKeyValueChangeKey : Any]?, context: UnsafeMutableRawPointer?) {
// First , check to make sure that the context matches the adjusting exposure context,
// Otherwise, pass the observation on to super.
if context == &adjustingExposureContext {
let device = object as! AVCaptureDevice
// then determine if the camera has stopped adjusting exposure , and if the locked mode is supported.
if !device.isAdjustingExposure , device.isExposureModeSupported(.locked){
// remove self from the observer to stop subsequent notification,
device.removeObserver(self, forKeyPath: kExposure, context: &adjustingExposureContext)
DispatchQueue.main.async {
do{
try device.lockForConfiguration()
device.exposureMode = .locked
device.unlockForConfiguration()
}
catch{
print("Error exposing on POI: \(String(describing: error.localizedDescription))")
}
}// DispatchQueue.main.async
}// if !device.isAdjustingExposure , device.isExposureModeSupported(.locked)
}// if context == &adjustingExposureContext {
else{
super.observeValue(forKeyPath: keyPath, of: object, change: change, context: context)
}
}
Upvotes: 1
Reputation: 633
If you're looking for auto-exposure, set a key-value observer for "adjustingExposure" and set the exposure mode to AVCaptureExposureModeContinuousAutoExposure. If you're trying to implement manual exposure, have a look at this WWDC session on camera controls.
Upvotes: 0