Camera2预览和捕获的图像看起来不同

Question

默认情况下，我会得到一个旋转-90度的捕获图像，我需要将其向后旋转，但它的高度与屏幕的高度不同，因此我的图像不会填充屏幕。

在照片后的横向模式下，它只显示拍摄图像的右上角。。

我试过了所有可用的样品，但找不到解决方案。

private void SetUpCameraOutputs(int width, int height)
{
_manager = (CameraManager)_context.GetSystemService(Context.CameraService);
string[] cameraIds = _manager.GetCameraIdList();
_cameraId = cameraIds[0];
CameraCharacteristics chararc = _manager.GetCameraCharacteristics(cameraIds[i])
var characteristics = _manager.GetCameraCharacteristics(_cameraId);
var map = (StreamConfigurationMap)characteristics.Get(CameraCharacteristics.ScalerStreamConfigurationMap);
if (_supportedJpegSizes == null && characteristics != null){
_supportedJpegSizes = ((StreamConfigurationMap)characteristics.Get(CameraCharacteristics.ScalerStreamConfigurationMap)).GetOutputSizes((int)ImageFormatType.Jpeg);
}
if (_supportedJpegSizes != null && _supportedJpegSizes.Length > 0){
_idealPhotoSize = GetOptimalSize(_supportedJpegSizes, 1050, 1400); 
}
_imageReader = ImageReader.NewInstance(_idealPhotoSize.Width, _idealPhotoSize.Height, ImageFormatType.Jpeg, 1);
var readerListener = new ImageAvailableListener();
readerListener.Photo += (sender, buffer) =>
{
Photo?.Invoke(this, buffer);
};
_flashSupported = HasFLash(characteristics);
_imageReader.SetOnImageAvailableListener(readerListener, _backgroundHandler);

_previewSize = GetOptimalSize(map.GetOutputSizes(Class.FromType(typeof(SurfaceTexture))), _idealPhotoSize.Height, _idealPhotoSize.Width);
}

TakePhoto方法：

public void TakePhoto()
{
if (_context == null || CameraDevice == null) return;
if (_captureBuilder == null)
_captureBuilder = CameraDevice.CreateCaptureRequest(CameraTemplate.StillCapture);
_captureBuilder.AddTarget(_imageReader.Surface);
_captureBuilder.Set(CaptureRequest.ControlAfMode, (int)ControlAFMode.ContinuousPicture);
var windowManager = _context.GetSystemService(Context.WindowService).JavaCast<IWindowManager>();
var rotation = windowManager.DefaultDisplay.Rotation;
_captureBuilder.Set(CaptureRequest.JpegOrientation, new Integer(Orientations.Get((int)rotation)));
_previewSession.StopRepeating();
_previewSession.Capture(_captureBuilder.Build(),
new CameraCaptureStillPictureSessionCallback
{
OnCaptureCompletedAction = session =>
{
UnlockFocus();
}
}, null);
}

我的OnPhoto方法：

private void OnPhoto(object sender, byte[] imgSource)
{
Android.Graphics.Bitmap bitmap = BitmapFactory.DecodeByteArray(imgSource, 0, imgSource.Length);
var windowManager = _context.GetSystemService(Context.WindowService).JavaCast<IWindowManager>();
var rotation = windowManager.DefaultDisplay.Rotation;
if (rotation == SurfaceOrientation.Rotation0 || rotation == SurfaceOrientation.Rotation180)
{
bitmap = resizeAndRotate(bitmap, bitmap.Width, bitmap.Height); //rotate bitmap by 90
}
var SkBitmap = bitmap.ToSKBitmap();
Application.Current.Properties["bitmap"] = SkBitmap;
Device.BeginInvokeOnMainThread(() =>
{
_currentElement?.PictureTaken();
});
}

Answer 1

为纵向模式创建位图时，必须更改位图的宽度和高度。因此宽度变为高度，高度变为肖像图像的宽度。

int newWidth = oldHeight;
int newHeight = oldWidth;
Bitmap newBitmap  =Bitmap.createScaledBitmap(oldbitmap,newWidth,newHeight,true);

现在你完成了，newBitmap在它的真实面上没有拉伸。

根据您的代码，只需使用以下选项恢复位图宽度和高度：

bitmap = resizeAndRotate(bitmap, bitmap.height, bitmap.width);