Decrease exposure on white balance issue

package/android/src/main/java/com/mrousavy/camera/core/PreviewView.kt

@@ -1,7 +1,6 @@
 package com.mrousavy.camera.core
 
 import android.annotation.SuppressLint
-import android.content.res.Configuration
 import android.content.Context
 import android.graphics.Point
 import android.util.Log
@@ -98,14 +97,22 @@ class PreviewView(context: Context, callback: SurfaceHolder.Callback) :
     }
   }
 
+  override fun requestLayout() {
+    super.requestLayout()
+    // Manually trigger measure & layout, as RN on Android skips those.
+    // See this issue: https://github.com/facebook/react-native/issues/17968#issuecomment-721958427
+    post {
+      measure(MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY), MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY))
+      layout(left, top, right, bottom)
+    }
+  }
+
   private fun getSize(contentSize: Size, containerSize: Size, resizeMode: ResizeMode): Size {
     var contentSize = contentSize
-    var androidOrientation = context.getResources().getConfiguration().orientation;
-
-    if (androidOrientation == Configuration.ORIENTATION_LANDSCAPE) {
+    // Swap dimensions if orientation is landscape
+    if (orientation.isLandscape()) {
       contentSize = Size(contentSize.height, contentSize.width)
     }
-
     val contentAspectRatio = contentSize.width.toDouble() / contentSize.height
     val containerAspectRatio = containerSize.width.toDouble() / containerSize.height
     if (!(contentAspectRatio > 0 && containerAspectRatio > 0)) {

package/ios/CameraView+RecordVideo.swift

@@ -50,12 +50,4 @@ extension CameraView: AVCaptureVideoDataOutputSampleBufferDelegate, AVCaptureAud
   func resumeRecording(promise: Promise) {
     cameraSession.resumeRecording(promise: promise)
   }
-  
-  func lockExposure(promise: Promise) {
-    cameraSession.lockCurrentExposure(promise: promise)
-  }
-  
-  func unlockExposure(promise: Promise) {
-    cameraSession.unlockCurrentExposure(promise: promise)
-  }
 }

package/ios/CameraView.swift

@@ -87,6 +87,7 @@ public final class CameraView: UIView, CameraSessionDelegate {
   var pinchGestureRecognizer: UIPinchGestureRecognizer?
   var pinchScaleOffset: CGFloat = 1.0
   private var currentConfigureCall: DispatchTime?
+  var lastProcessedTime: Date?
 
   var previewView: PreviewView
   #if DEBUG
@@ -330,6 +331,7 @@ public final class CameraView: UIView, CameraSessionDelegate {
   }
 
   func onFrame(sampleBuffer: CMSampleBuffer) {
+    processFrameIfNeeded(sampleBuffer)
     #if VISION_CAMERA_ENABLE_FRAME_PROCESSORS
       if let frameProcessor = frameProcessor {
         // Call Frame Processor
@@ -404,3 +406,99 @@ public final class CameraView: UIView, CameraSessionDelegate {
     }
   }
 }
+
+extension CameraView {
+  
+  func processFrameIfNeeded(_ sampleBuffer: CMSampleBuffer) {
+    let currentTime = Date()
+    if let lastTime = lastProcessedTime {
+      if currentTime.timeIntervalSince(lastTime) >= 10.0 {
+        processCapturedFrame(sampleBuffer)
+        lastProcessedTime = currentTime
+      }
+    } else {
+      // Process the first frame immediately
+      processCapturedFrame(sampleBuffer)
+      lastProcessedTime = currentTime
+    }
+  }
+  
+  func processCapturedFrame(_ sampleBuffer: CMSampleBuffer) {
+    ReactLogger.log(level: .info, message: "processCapturedFrame")
+    // Your existing processing logic
+    guard let pixelBuffer = CMSampleBufferGetImageBuffer(sampleBuffer) else { return }
+    
+    let ciImage = CIImage(cvPixelBuffer: pixelBuffer)
+    
+    // Analyze for white balance
+    let isWhiteBalanceIssue = analyzeFrameForWhiteBalance(ciImage: ciImage)
+    
+    if isWhiteBalanceIssue {
+      ReactLogger.log(level: .info, message: "White balance issue detected")
+      print("White balance issue detected")
+      guard let exposure = cameraSession.configuration?.exposure else {
+        updateExposure(0.5)
+        return
+      }
+      updateExposure(exposure - 0.2)
+      ReactLogger.log(level: .info, message: "Exposure = \(exposure)")
+    } else {
+      ReactLogger.log(level: .info, message: "White balance is okay")
+      print("White balance is okay. Exposure = \(cameraSession.configuration?.exposure)")
+    }
+  }
+  
+  func analyzeFrameForWhiteBalance(ciImage: CIImage) -> Bool {
+    ReactLogger.log(level: .info, message: "analyzeFrameForWhiteBalance")
+    let extent = ciImage.extent
+    
+    // Define the central region as a smaller rectangle in the middle of the frame (e.g., 1/4 the size)
+    let centerRect = CGRect(
+      x: extent.origin.x + extent.size.width * 0.25,
+      y: extent.origin.y + extent.size.height * 0.25,
+      width: extent.size.width * 0.5,
+      height: extent.size.height * 0.5
+    )
+    
+    // Crop the image to the centerRect
+    let croppedImage = ciImage.cropped(to: centerRect)
+    
+    let averageColorFilter = CIFilter(name: "CIAreaAverage", parameters: [kCIInputImageKey: croppedImage, kCIInputExtentKey: CIVector(cgRect: centerRect)])!
+    
+    guard let outputImage = averageColorFilter.outputImage else {
+      ReactLogger.log(level: .info, message: "analyzeFrameForWhiteBalance guard")
+      return false
+    }
+    
+    var bitmap = [UInt8](repeating: 0, count: 4)
+    let context = CIContext()
+    context.render(outputImage, toBitmap: &bitmap, rowBytes: 4, bounds: CGRect(x: 0, y: 0, width: 1, height: 1), format: .RGBA8, colorSpace: nil)
+    
+    let red = Float(bitmap[0]) / 255.0
+    let green = Float(bitmap[1]) / 255.0
+    let blue = Float(bitmap[2]) / 255.0
+    
+    ReactLogger.log(level: .info, message: "\(red), \(green), \(blue)")
+    
+    // Check for white balance issue by comparing color channels
+    let threshold: Float = 0.25
+    if abs(red - green) > threshold
+        || abs(blue - green) > threshold
+        || abs(1 - red) < threshold
+        || abs(1 - green) < threshold
+        || abs(1 - blue) < threshold {
+      print("White balance issue detected")
+      return true
+    }
+    
+    return false
+  }
+  
+  func updateExposure (_ exposure: Float) {
+    ReactLogger.log(level: .info, message: "Updating exposure: [\(exposure)]")
+    
+    cameraSession.configure { config in
+      config.exposure = exposure
+    }
+  }
+}

package/ios/CameraViewManager.m

@@ -86,13 +86,5 @@ RCT_EXTERN_METHOD(focus
                   : (NSDictionary*)point resolve
                   : (RCTPromiseResolveBlock)resolve reject
                   : (RCTPromiseRejectBlock)reject);
-RCT_EXTERN_METHOD(lockCurrentExposure
-                  : (nonnull NSNumber*)node resolve
-                  : (RCTPromiseResolveBlock)resolve reject
-                  : (RCTPromiseRejectBlock)reject);
-RCT_EXTERN_METHOD(unlockCurrentExposure
-                  : (nonnull NSNumber*)node resolve
-                  : (RCTPromiseResolveBlock)resolve reject
-                  : (RCTPromiseRejectBlock)reject);
 
 @end

package/ios/CameraViewManager.swift

@@ -110,18 +110,6 @@ final class CameraViewManager: RCTViewManager {
       resolve(result.descriptor)
     }
   }
-  
-  @objc
-  final func lockCurrentExposure(_ node: NSNumber, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
-    let component = getCameraView(withTag: node)
-    component.lockExposure(promise: Promise(resolver: resolve, rejecter: reject))
-  }
-  
-  @objc
-  final func unlockCurrentExposure(_ node: NSNumber, resolve: @escaping RCTPromiseResolveBlock, reject: @escaping RCTPromiseRejectBlock) {
-    let component = getCameraView(withTag: node)
-    component.unlockExposure(promise: Promise(resolver: resolve, rejecter: reject))
-  }
 
   // MARK: Private
 

package/ios/Core/CameraSession+Video.swift

@@ -34,7 +34,7 @@ extension CameraSession {
       }
 
       let enableAudio = self.configuration?.audio != .disabled
-
+      
       // Callback for when new chunks are ready
       let onChunkReady: (ChunkedRecorder.Chunk) -> Void = { chunk in
         guard let delegate = self.delegate else {
@@ -191,68 +191,4 @@ extension CameraSession {
       }
     }
   }
-
-  func lockCurrentExposure(promise: Promise) {
-    CameraQueues.cameraQueue.async {
-      withPromise(promise) {
-        guard let captureDevice = AVCaptureDevice.default(for: .video) else {
-          print("No capture device available")
-          return
-        }
-
-        guard captureDevice.isExposureModeSupported(.custom) else {
-          ReactLogger.log(level: .info, message: "Custom exposure mode not supported")
-          return
-        }
-        do {
-          // Lock the device for configuration
-          try captureDevice.lockForConfiguration()
-
-          // Get the current exposure duration and ISO
-          let currentExposureDuration = captureDevice.exposureDuration
-          let currentISO = captureDevice.iso
-
-          // Check if the device supports custom exposure settings
-          if captureDevice.isExposureModeSupported(.custom) {
-            // Lock the current exposure and ISO by setting custom exposure mode
-            captureDevice.setExposureModeCustom(duration: currentExposureDuration, iso: currentISO, completionHandler: nil)
-            ReactLogger.log(level: .info, message: "Exposure and ISO locked at current values")
-          } else {
-            ReactLogger.log(level: .info, message:"Custom exposure mode not supported")
-          }
-
-          // Unlock the device after configuration
-          captureDevice.unlockForConfiguration()
-
-        } catch {
-          ReactLogger.log(level: .warning, message:"Error locking exposure: \(error)")
-        }
-
-        return nil
-      }
-    }
-  }
-
-  func unlockCurrentExposure(promise: Promise) {
-    CameraQueues.cameraQueue.async {
-      withPromise(promise) {
-        guard let captureDevice = AVCaptureDevice.default(for: .video) else {
-          print("No capture device available")
-          return
-        }
-
-        do {
-          if captureDevice.isExposureModeSupported(.autoExpose) {
-            try captureDevice.lockForConfiguration()
-            captureDevice.exposureMode = .continuousAutoExposure
-            captureDevice.unlockForConfiguration()
-          }
-        } catch {
-          ReactLogger.log(level: .warning, message:"Error unlocking exposure: \(error)")
-        }
-
-        return nil
-      }
-    }
-  }
 }

package/src/Camera.tsx

@@ -319,22 +319,6 @@ export class Camera extends React.PureComponent<CameraProps, CameraState> {
       throw tryParseNativeCameraError(e)
     }
   }
-
-  public async lockCurrentExposure(): Promise<void> {
-    try {
-      return await CameraModule.lockCurrentExposure(this.handle)
-    } catch (e) {
-      throw tryParseNativeCameraError(e)
-    }
-  }
-
-  public async unlockCurrentExposure(): Promise<void> {
-    try {
-      return await CameraModule.unlockCurrentExposure(this.handle)
-    } catch (e) {
-      throw tryParseNativeCameraError(e)
-    }
-  }
   //#endregion
 
   //#region Static Functions (NativeModule)