Fix luminance calculation for Android in lanscape mode

android/build.gradle

@@ -34,10 +34,10 @@ android {
   compileSdkVersion getExtOrIntegerDefault('compileSdkVersion')
   buildToolsVersion getExtOrDefault('buildToolsVersion')
   defaultConfig {
-    minSdkVersion 19
+    minSdkVersion 21
     targetSdkVersion getExtOrIntegerDefault('targetSdkVersion')
-    versionCode 131
-    versionName "1.3.1"
+    versionCode 132
+    versionName "1.3.2"
 
   }
 
@@ -135,5 +135,6 @@ dependencies {
   implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
   implementation "androidx.camera:camera-core:1.1.0-alpha06"
   implementation "com.facebook.react:react-native:+"  // From node_modules
+  implementation 'com.quickbirdstudios:opencv:4.5.3.0'
   api project(":react-native-vision-camera")
 }

android/settings.gradle

@@ -0,0 +1 @@
+include ':opencv'

android/src/main/java/com/visioncamerafacedetector/VisionCameraFaceDetectorPlugin.kt

@@ -67,7 +67,7 @@ class VisionCameraFaceDetectorPlugin: FrameProcessorPlugin("faceDetector") {
 
             var f = Rect(face.boundingBox.left, face.boundingBox.top, face.boundingBox.right, face.boundingBox.bottom)
 
-            val luminanceStats:LuminanceStats = imageService.getLuminanceStats(f, image.width, rotationDegrees)
+            val luminanceStats:LuminanceStats = imageService.getLuminanceStats(f, image.width)
 
             val imageWidth = if (rotated) image.height else image.width
             val imageHeight = if (rotated) image.width else image.height

android/src/main/java/com/visioncamerafacedetector/services/ImageQualityService.kt

@@ -3,6 +3,12 @@ package com.visioncamerafacedetector.services
 import android.graphics.Rect
 import android.util.Log
 import androidx.camera.core.ImageProxy
+import org.opencv.core.Core
+import org.opencv.core.CvType
+import org.opencv.core.Mat
+import org.opencv.core.Point
+import org.opencv.core.Size
+import org.opencv.imgproc.Imgproc
 import java.nio.ByteBuffer
 import kotlin.math.abs
 
@@ -12,33 +18,38 @@ data class LuminanceStats(val scene: Double, val splitLightingDifference:Double)
 
 class ImageQualityService(buffer: ImageProxy) {
 
-  val imageBuffer: ImageProxy = buffer
+  // Since format in ImageAnalysis is YUV, image.planes[0] contains the Y (luminance) plane
+  val luminanceByteArray: ByteArray = imageProxyToByteArray(buffer)
+  val rotationDegrees: Int = buffer.imageInfo.rotationDegrees
 
-  private fun ByteBuffer.toByteArray(): ByteArray {
-    rewind()
-    val data = ByteArray(remaining())
-    get(data)
-    return data
+  private fun imageProxyToByteArray(imageProxy: ImageProxy): ByteArray {
+      val yBuffer = imageProxy.planes[0].buffer
+      val ySize = yBuffer.remaining()
+      val yByteArray = ByteArray(ySize)
+      yBuffer.get(yByteArray)
+      val matYuv = Mat(imageProxy.height, imageProxy.width, CvType.CV_8UC1)
+      matYuv.put(0, 0, yByteArray)
+        if (imageProxy.imageInfo.rotationDegrees==90) {
+          val matYuv = Mat(imageProxy.height, imageProxy.width, CvType.CV_8UC1)
+          matYuv.put(0, 0, yByteArray)
+          val rotatedMat = Mat(matYuv.width(), matYuv.height(),CvType.CV_8UC1)
+          Core.rotate(matYuv,rotatedMat, Core.ROTATE_90_COUNTERCLOCKWISE)
+          val yRotatedByteArray = ByteArray(ySize)
+          rotatedMat.get(0, 0, yRotatedByteArray)
+        return yRotatedByteArray
+      }
+      return yByteArray
   }
 
   fun getLuminance(): Double {
-    // Since format in ImageAnalysis is YUV, image.planes[0] contains the Y (luminance) plane
-    val buffer = imageBuffer.planes[0].buffer
-    // Extract image data from callback object
-    val data = buffer.toByteArray()
     // Convert the data into an array of pixel values
-    val pixels = data.map { it.toInt() and 0xFF }
+    val pixels = luminanceByteArray.map { it.toInt() and 0xFF }
     // Compute average luminance for the image
-
     return pixels.average() / 255
   }
 
-  fun getLuminanceStats(faceBounds:Rect, imageWidth:Int, rotationDegrees: Int): LuminanceStats {
+  fun getLuminanceStats(faceBounds:Rect, imageWidth:Int): LuminanceStats {
 
-    // Since format in ImageAnalysis is YUV, image.planes[0] contains the Y (luminance) plane
-    val buffer = imageBuffer.planes[0].buffer
-    // Extract image data from callback object
-    val data = buffer.toByteArray()
     // Compute average luminance for the image
 
     val midHorizontal = (faceBounds.right - faceBounds.left) / 2 + faceBounds.left
@@ -50,7 +61,7 @@ class ImageQualityService(buffer: ImageProxy) {
     var scene = 0
     var left = 0
     var right = 0
-    data.forEachIndexed { index, byte ->
+    luminanceByteArray.forEachIndexed { index, byte ->
       val y = index % imageWidth
       val x = index / imageWidth
 
@@ -60,17 +71,11 @@ class ImageQualityService(buffer: ImageProxy) {
       } else if (midHorizontal <= x && x < faceBounds.right && faceBounds.top <= y && y < faceBounds.bottom) {
         luminanceR += (byte.toInt() and 0xFF).toDouble() / 255.0
         right += 1
-      } else if (midVertical >= y && rotationDegrees == 90){
-        // Monitor only top of the scene
-        luminanceScene += (byte.toInt() and 0xFF).toDouble()  / 255.0
-        scene += 1
-      } else if (midVertical < y && rotationDegrees == 270){
-        // Monitor only top of the scene
+      } else {
         luminanceScene += (byte.toInt() and 0xFF).toDouble()  / 255.0
         scene += 1
       }
     }
-
     return LuminanceStats(luminanceScene/scene, abs((luminanceR / right) - (luminanceL / left)))
   }
 }

package.json

@@ -1,6 +1,6 @@
 {
   "name": "vision-camera-facedetector",
-  "version": "1.3.1",
+  "version": "1.3.2",
   "description": "VisionCamera Frame Processor Plugin that uses MLKit Face Recognition API to recognize faces",
   "main": "lib/commonjs/index",
   "module": "lib/module/index",