android - 将CameraX捕获的ImageProxy转换为位图

我使用CameraX时，很难将捕获的ImageProxy转换为Bitmap。经过搜索和尝试，我制定了解决方案。后来我发现它不是最佳选择，所以我更改了设计。那迫使我放弃了数小时的工作。

由于我（或其他人）将来可能需要它，因此我决定在此处发布问题并对其进行张贴和回答，以供参考和审查。如果有的话，随时添加更好的答案。

相关代码为：

class ImagePickerActivity : AppCompatActivity() {
    private var width = 325
    private var height = 205

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_image_picker)

        view_finder.post { startCamera() }
    }

    @RequiresApi(Build.VERSION_CODES.LOLLIPOP)
    private fun startCamera() {
        // Create configuration object for the viewfinder use case
        val previewConfig = PreviewConfig.Builder().apply {
            setTargetAspectRatio(Rational(1, 1))
            //setTargetResolution(Size(width, height))
            setLensFacing(CameraX.LensFacing.BACK)
            setTargetAspectRatio(Rational(width, height))
        }.build()

        }

        // Create configuration object for the image capture use case
        val imageCaptureConfig = ImageCaptureConfig.Builder()
            .apply {
                setTargetAspectRatio(Rational(1, 1))
                // We don't set a resolution for image capture instead, we
                // select a capture mode which will infer the appropriate
                // resolution based on aspect ration and requested mode
                setCaptureMode(ImageCapture.CaptureMode.MIN_LATENCY)
            }.build()

        // Build the image capture use case and attach button click listener
        val imageCapture = ImageCapture(imageCaptureConfig)
        capture_button.setOnClickListener {

            imageCapture.takePicture(object : ImageCapture.OnImageCapturedListener() {
                override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
                        //How do I get the bitmap here?
                        //imageView.setImageBitmap(someBitmap)
                }

                override fun onError(useCaseError: ImageCapture.UseCaseError?, message: String?, cause: Throwable?) {
                    val msg = "Photo capture failed: $message"
                    Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
                    Log.e(localClassName, msg)
                    cause?.printStackTrace()
                }
            })
        }
        CameraX.bindToLifecycle(this, preview, imageCapture)
    }

}

最佳答案

略作修改的版本。在inline use上使用Closable函数ImageProxy

imageCapture.takePicture(
           object : ImageCapture.OnImageCapturedListener() {
               override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
                     image.use { image ->
                           val bitmap: Bitmap? = image?.let {
                                imageProxyToBitmap(it)
                            } ?: return
                      }
          }
       })

  private fun imageProxyToBitmap(image: ImageProxy): Bitmap {
        val buffer: ByteBuffer = image.planes[0].buffer
        val bytes = ByteArray(buffer.remaining())
        buffer.get(bytes)
        return BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
    }