我正在使用CameraX，很难将捕获的ImageProxy转换为Bitmap。经过搜索和尝试，我制定了一个解决方案。后来我发现它不是最佳的，所以我改变了设计。这迫使我放弃了工作时间。
由于我(或其他人(将来可能需要它，我决定在这里发布作为问题并发布和回答以供参考和审查。如果您有更好的答案，请随时添加。
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)
}
}
所以解决方案是将扩展方法添加到Image，这是代码
class ImagePickerActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_image_picker)
}
private fun startCamera() {
val imageCapture = ImageCapture(imageCaptureConfig)
capture_button.setOnClickListener {
imageCapture.takePicture(object : ImageCapture.OnImageCapturedListener() {
override fun onCaptureSuccess(image: ImageProxy?, rotationDegrees: Int) {
imageView.setImageBitmap(image.image?.toBitmap())
}
//.....
})
}
}
}
fun Image.toBitmap(): Bitmap {
val buffer = planes[0].buffer
buffer.rewind()
val bytes = ByteArray(buffer.capacity())
buffer.get(bytes)
return BitmapFactory.decodeByteArray(bytes, 0, bytes.size)
}
略有修改的版本。在ClosableImageProxy上使用inline函数use
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)
}
这是使用MLKit自己的实现的最安全的方法。 经过测试并在 MLKit 版本 1.0.1 上运行
import com.google.mlkit.vision.common.internal.ImageConvertUtils;
Image mediaImage = imageProxy.getImage();
InputImage image = InputImage.fromMediaImage(mediaImage, imageProxy.getImageInfo().getRotationDegrees());
Bitmap bitmap = ImageConvertUtils.getInstance().getUpRightBitmap(image)
Backbelt的答案的Java实现。
private Bitmap imageProxyToBitmap(ImageProxy image) {
ByteBuffer buffer = image.getPlanes()[0].getBuffer();
byte[] bytes = new byte[buffer.remaining()];
buffer.get(bytes);
return BitmapFactory.decodeByteArray(bytes,0,bytes.length,null);
}
目前takePicture方法有第二个版本(CameraX版本1.0.0-beta03(。它提供了几种持久化图像的方法(OutputStream或者File在您的情况下可能很有用(。
如果您仍然想将ImageProxy转换为Bitmap这是我对类似问题的回答，它给出了此转换的正确实现。
请看一下这个答案。您需要将其应用于您的问题只是从您的图像代理中获取图像
Image img = imaget.getImage();