使用 CameraX 拍摄的图像不具有设备相机产生的高分辨率输出尺寸

Question

我试图通过cameraX实现获得高分辨率图像。通过下面的代码，我可以看到对于设备的后置摄像头，我测试了分辨率为4000x3000的条目。

    @RequiresApi(Build.VERSION_CODES.M)
fun getPossibleOutputSizes(id: String) {
    val cameraManager = context?.getSystemService(Context.CAMERA_SERVICE) as CameraManager
    val sizes = cameraManager?.getCameraCharacteristics(id)?.get(SCALER_STREAM_CONFIGURATION_MAP)?.getHighResolutionOutputSizes(ImageFormat.JPEG)
    if (sizes != null) {
        println("got possible resolutions:")
        println(sizes.joinToString("\n"))
    }
}

下面是设置相机的代码。这是一个示例应用程序，我用来检查由cameraX takePhoto调用提供的输出分辨率。

/** Declare and bind preview, capture and analysis use cases */
@SuppressLint("RestrictedApi", "ServiceCast", "UnsafeOptInUsageError")
private fun bindCameraUseCases() {

    // Get screen metrics used to setup camera for full screen resolution
    val metrics = windowManager.getCurrentWindowMetrics().bounds
    Log.d(TAG, "Screen metrics: ${metrics.width()} x ${metrics.height()}")

    val screenAspectRatio = aspectRatio(metrics.width(), metrics.height())
    Log.d(TAG, "Preview aspect ratio: $screenAspectRatio")

    val rotation = fragmentCameraBinding.viewFinder.display.rotation

    // CameraProvider
    val cameraProvider = cameraProvider
            ?: throw IllegalStateException("Camera initialization failed.")

    // CameraSelector
    var cameraSelector = CameraSelector.Builder().requireLensFacing(lensFacing).build()

    selectExternalOrBestCamera(cameraProvider)?.let { returnedCameraSelector ->
        cameraSelector = returnedCameraSelector


    }
    // Preview
    preview = Preview.Builder()
            // We request aspect ratio but no resolution
            .setTargetAspectRatio(screenAspectRatio)//either RATIO_4_3 or RATIO_16_9
            // Set initial target rotation
            .setTargetRotation(rotation)
            .build()

    // ImageCapture
    imageCapture = ImageCapture.Builder()
            .setCaptureMode(ImageCapture.CAPTURE_MODE_ZERO_SHUTTER_LAG)
            // We request aspect ratio but no resolution to match preview config, but letting
            // CameraX optimize for whatever specific resolution best fits our use cases
            // Set initial target rotation, we will have to call this again if rotation changes
            // during the lifecycle of this use case
            //.setTargetAspectRatio(AspectRatio.RATIO_4_3)//tried both RATIO_4_3 and RATIO_16_9
            .setTargetResolution(Size(3000, 4000))//tried 4000 * 3000 too..
            .setTargetRotation(rotation)
            //.setDefaultCaptureConfig(config)
            .build()
    // Must unbind the use-cases before rebinding them
    cameraProvider.unbindAll()

    try {
        // A variable number of use-cases can be passed here -
        // camera provides access to CameraControl & CameraInfo
        camera = cameraProvider.bindToLifecycle(
                this, cameraSelector, preview, imageCapture)

        // Attach the viewfinder's surface provider to preview use case
        preview?.setSurfaceProvider(fragmentCameraBinding.viewFinder.surfaceProvider)
        observeCameraState(camera?.cameraInfo!!)
    } catch (exc: Exception) {
        Log.e(TAG, "Use case binding failed", exc)
    }
}

我尝试使用cameraX中的可用配置，但无法获得与我在

getPossibleOutputSizes

中获得的相同分辨率的高分辨率输出。我测试的所有设备似乎都是这种情况。但设备相机能够提供该分辨率的图像，基于camera2的实现也是如此。

这是cameraX的限制还是我错过了什么？

Answer 1

不幸的是，截至2023年1月，使用

getHighResolutionOutputSizes

返回的高分辨率无法与CameraX一起使用。我不知道有什么解决方法。错误报告和当前状态可以在这里找到：https://issuetracker.google.com/issues/162121234 目前预计该功能应该在 CameraX 1.3 版本中附带。

编辑 20.04.23： 随着昨天发布的版本 1.3.0-alpha06 ，现在应该可用：https://developer.android.com/jetpack/androidx/releases/camera#1.3.0-alpha06

Answer 2

从 Camerax 1.3.0 开始，您现在可以使用

setAllowedResolutionMode

类的

ResolutionSelector.Builder

。示例：

 val resolutionSelector = ResolutionSelector.Builder()
     .setAllowedResolutionMode(ResolutionSelector.PREFER_HIGHER_RESOLUTION_OVER_CAPTURE_RATE)
     .setAspectRatioStrategy(AspectRatioStrategy.RATIO_4_3_FALLBACK_AUTO_STRATEGY)
     .setResolutionStrategy(ResolutionStrategy.HIGHEST_AVAILABLE_STRATEGY)
     .build()

然后使用：

imageCapture = ImageCapture.Builder()
    .setTargetRotation(viewBinding.viewFinder.display.rotation)
    .setResolutionSelector(resolutionSelector)
    .build()

这应该可以在文档中提供高分辨率捕获：

自 Android 12 起，某些设备可能支持最大分辨率 传感器像素模式，这使他们能够捕捉额外的超高 决议检索自 android.hardware.camera2.CameraCharacteristics.SCALER_STREAM_CONFIGURATION_MAP_MAXIMUM_RESOLUTION 。该模式不允许应用程序选择那些超高 决议。

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