android - 如何将检测到的人脸提取到位图中？

问题描述

我有以下代码

图形叠加.kt

open class GraphicOverlay(context: Context?, attrs: AttributeSet?) :
    View(context, attrs) {

    private val lock = Any()
    private val graphics: MutableList<Graphic> = ArrayList()
    var mScale: Float? = null
    var mOffsetX: Float? = null
    var mOffsetY: Float? = null
    var cameraSelector: Int = CameraSelector.LENS_FACING_FRONT

    abstract class Graphic(private val overlay: GraphicOverlay) {

        abstract fun draw(canvas: Canvas?)

        fun calculateRect(height: Float, width: Float, boundingBoxT: Rect): RectF {

            // for land scape
            fun isLandScapeMode(): Boolean {
                return overlay.context.resources.configuration.orientation == Configuration.ORIENTATION_LANDSCAPE
            }

            fun whenLandScapeModeWidth(): Float {
                return when (isLandScapeMode()) {
                    true -> width
                    false -> height
                }
            }

            fun whenLandScapeModeHeight(): Float {
                return when (isLandScapeMode()) {
                    true -> height
                    false -> width
                }
            }

            val scaleX = overlay.width.toFloat() / whenLandScapeModeWidth()
            val scaleY = overlay.height.toFloat() / whenLandScapeModeHeight()
            val scale = scaleX.coerceAtLeast(scaleY)
            overlay.mScale = scale

            // Calculate offset (we need to center the overlay on the target)
            val offsetX = (overlay.width.toFloat() - ceil(whenLandScapeModeWidth() * scale)) / 2.0f
            val offsetY =
                (overlay.height.toFloat() - ceil(whenLandScapeModeHeight() * scale)) / 2.0f

            overlay.mOffsetX = offsetX
            overlay.mOffsetY = offsetY

            val mappedBox = RectF().apply {
                left = boundingBoxT.right * scale + offsetX
                top = boundingBoxT.top * scale + offsetY
                right = boundingBoxT.left * scale + offsetX
                bottom = boundingBoxT.bottom * scale + offsetY
            }

            // for front mode
            if (overlay.isFrontMode()) {
                val centerX = overlay.width.toFloat() / 2
                mappedBox.apply {
                    left = centerX + (centerX - left)
                    right = centerX - (right - centerX)
                }
            }
            return mappedBox
        }
    }

    fun isFrontMode() = cameraSelector == CameraSelector.LENS_FACING_FRONT

    fun toggleSelector() {
        cameraSelector =
            if (cameraSelector == CameraSelector.LENS_FACING_BACK) CameraSelector.LENS_FACING_FRONT
            else CameraSelector.LENS_FACING_BACK
    }

    fun clear() {
        synchronized(lock) { graphics.clear() }
        postInvalidate()
    }

    fun add(graphic: Graphic) {
        synchronized(lock) { graphics.add(graphic) }
    }

    fun remove(graphic: Graphic) {
        synchronized(lock) { graphics.remove(graphic) }
        postInvalidate()
    }

    override fun onDraw(canvas: Canvas?) {
        super.onDraw(canvas)
        synchronized(lock) {
            for (graphic in graphics) {
                graphic.draw(canvas)
            }
        }
    }

}

FaceContourGraphic.kt

class FaceContourGraphic(
    overlay: GraphicOverlay,
    private val face: Face,
    private val imageRect: Rect
) : GraphicOverlay.Graphic(overlay) {

    private val facePositionPaint: Paint
    private val idPaint: Paint
    private val boxPaint: Paint

    init {
        val selectedColor = Color.WHITE

        facePositionPaint = Paint()
        facePositionPaint.color = selectedColor

        idPaint = Paint()
        idPaint.color = selectedColor

        boxPaint = Paint()
        boxPaint.color = selectedColor
        boxPaint.style = Paint.Style.STROKE
        boxPaint.strokeWidth = BOX_STROKE_WIDTH
    }

    override fun draw(canvas: Canvas?) {
        val rect = calculateRect(
            imageRect.height().toFloat(),
            imageRect.width().toFloat(),
            face.boundingBox
        )
        canvas?.drawRect(rect, boxPaint)
    }

    companion object {
        private const val BOX_STROKE_WIDTH = 5.0f
    }

}

SelfieAnalyzer.kt

abstract class SelfieAnalyzer<T> : ImageAnalysis.Analyzer {

    abstract val graphicOverlay: GraphicOverlay

    @SuppressLint("UnsafeExperimentalUsageError")
    override fun analyze(imageProxy: ImageProxy) {

        val mediaImage = imageProxy.image
        mediaImage?.let { image ->
            detectInImage(InputImage.fromMediaImage(image, imageProxy.imageInfo.rotationDegrees))
                .addOnSuccessListener { results ->
                    onSuccess(
                        results,
                        graphicOverlay,
                        image.cropRect
                    )
                    imageProxy.close()
                }
                .addOnFailureListener {
                    onFailure(it)
                    imageProxy.close()
                }
        }
    }

    protected abstract fun detectInImage(image: InputImage): Task<T>

    abstract fun stop()

    protected abstract fun onSuccess(
        results: T,
        graphicOverlay: GraphicOverlay,
        rect: Rect
    )

    protected abstract fun onFailure(e: Exception)

    companion object {
        const val TAG: String = "SelfieAnalyzer"
    }
}

FaceContourDetectionProcessor.kt

class FaceContourDetectionProcessor(private val view: GraphicOverlay) :
    SelfieAnalyzer<List<Face>>() {


    private val realTimeOpts = FaceDetectorOptions.Builder()
        .setPerformanceMode(FaceDetectorOptions.PERFORMANCE_MODE_FAST)
        .setContourMode(FaceDetectorOptions.CONTOUR_MODE_NONE)
        .build()

    private val detector = FaceDetection.getClient(realTimeOpts)

    override val graphicOverlay: GraphicOverlay
        get() = view

    override fun detectInImage(image: InputImage): Task<List<Face>> {
        return detector.process(image)
    }

    override fun stop() {
        try {
            detector.close()
        } catch (e: IOException) {
            Log.e(TAG, "Exception thrown while trying to close Face Detector: $e")
        }
    }

    override fun onSuccess(
        results: List<Face>,
        graphicOverlay: GraphicOverlay,
        rect: Rect
    ) {
        graphicOverlay.clear()
        results.forEach { face ->
            val faceGraphic = FaceContourGraphic(graphicOverlay, face, rect)

            graphicOverlay.add(faceGraphic)
        }

        graphicOverlay.postInvalidate()
    }

    override fun onFailure(e: Exception) {
        Log.w(TAG, "Face Detector failed.$e")
    }

    companion object {
        private const val TAG = "FaceDetectionProcessor"
    }

}

SelfieFragment.kt

class SelfieFragment : Fragment() {

 // runs on camera permission grant success
 private fun startCamera() {
        val cameraProviderFuture = ProcessCameraProvider.getInstance(requireContext())

        cameraProviderFuture.addListener({
            // Used to bind the lifecycle of cameras to the lifecycle owner
            val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

            // Preview
            val preview = Preview.Builder().build()
            preview.setSurfaceProvider(binding.viewFinder.surfaceProvider)

            imageCapture = ImageCapture.Builder().build()

            val imageAnalyzer = ImageAnalysis.Builder()
                .setBackpressureStrategy(STRATEGY_KEEP_ONLY_LATEST)
                .build()
                .also {
                    it.setAnalyzer(
                        cameraExecutor,
                        selectAnalyzer()
                    )
                }

            // Select front camera as a default
            val cameraSelector = CameraSelector.DEFAULT_FRONT_CAMERA


            try {
                // Unbind use cases before rebinding
                cameraProvider.unbindAll()

                // Bind use cases to camera
                cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview, imageCapture, imageAnalyzer
                )

            } catch (exc: Exception) {
                Log.e(TAG, "Use case binding failed", exc)
            }

        }, ContextCompat.getMainExecutor(context))
    }
  }
}

片段自拍.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context=".ui.fragments.SelfieFragment">

    <androidx.camera.view.PreviewView
        android:id="@+id/viewFinder"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <com.example.appname.customviews.GraphicOverlay
        android:id="@+id/graphic_overlay"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toBottomOf="@id/viewFinder"
        app:layout_constraintLeft_toLeftOf="@id/viewFinder"
        app:layout_constraintRight_toRightOf="@id/viewFinder"
        app:layout_constraintTop_toTopOf="@id/viewFinder" />

    <com.google.android.material.button.MaterialButton
        android:id="@+id/btnCamera"
        style="@style/Widget.MaterialComponents.Button.OutlinedButton.Icon"
        android:layout_width="wrap_content"
        android:layout_height="56dp"
        android:layout_marginBottom="16dp"
        android:background="@android:color/transparent"
        android:insetLeft="0dp"
        android:insetTop="0dp"
        android:insetRight="0dp"
        android:insetBottom="0dp"
        app:icon="@drawable/ic_photo_camera_48"
        app:iconGravity="textStart"
        app:iconPadding="0dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

我想创建检测到的人脸的位图，但我不知道如何，因为Faceapi 没有提供方法。

标签： androidface-detectionandroid-cameraxgoogle-mlkit

android - 如何将检测到的人脸提取到位图中？

问题描述

解决方案

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