我正在尝试使用新的 Camera2 API 来访问相机设置并应用缩放。 在旧的已弃用的 Camera API 中,代码如下:
Camera.Parameters parameters = mCamera.getParameters();
parameters.setZoom(zoomValue);
mCamera.setParameters(parameters);
考虑到 CameraManager,我们如何才能实现同样的目标 是用来打开相机的?
CameraManager.openCamera(cameraId, stateCallback, backgroundHandler);
最佳答案
使用下一个代码。使用您的目标 CaptureRequest.Builder 调用 setZoom ,以便在需要时使用预览或图片定位构建器。
使用 maxZoom 获取 UI 应计算缩放范围的阈值。 缩放范围将始终在 DEFAULT_ZOOM_FACTOR 和 maxZoom 之间。
调用setZoom后,要使新的缩放处于 Activity 状态,您仍然需要将其发送到当前的 CameraCaptureSession带有重复请求。
计算新缩放系数的代码 fragment :
public final class Zoom
{
private static final float DEFAULT_ZOOM_FACTOR = 1.0f;
@NonNull
private final Rect mCropRegion = new Rect();
public final float maxZoom;
@Nullable
private final Rect mSensorSize;
public final boolean hasSupport;
public Zoom(@NonNull final CameraCharacteristics characteristics)
{
this.mSensorSize = characteristics.get(CameraCharacteristics.SENSOR_INFO_ACTIVE_ARRAY_SIZE);
if (this.mSensorSize == null)
{
this.maxZoom = Zoom.DEFAULT_ZOOM_FACTOR;
this.hasSupport = false;
return;
}
final Float value = characteristics.get(CameraCharacteristics.SCALER_AVAILABLE_MAX_DIGITAL_ZOOM);
this.maxZoom = ((value == null) || (value < Zoom.DEFAULT_ZOOM_FACTOR))
? Zoom.DEFAULT_ZOOM_FACTOR
: value;
this.hasSupport = (Float.compare(this.maxZoom, Zoom.DEFAULT_ZOOM_FACTOR) > 0);
}
public void setZoom(@NonNull final CaptureRequest.Builder builder, final float zoom)
{
if (this.hasSupport == false)
{
return;
}
final float newZoom = MathUtils.clamp(zoom, Zoom.DEFAULT_ZOOM_FACTOR, this.maxZoom);
final int centerX = this.mSensorSize.width() / 2;
final int centerY = this.mSensorSize.height() / 2;
final int deltaX = (int)((0.5f * this.mSensorSize.width()) / newZoom);
final int deltaY = (int)((0.5f * this.mSensorSize.height()) / newZoom);
this.mCropRegion.set(centerX - deltaX,
centerY - deltaY,
centerX + deltaX,
centerY + deltaY);
builder.set(CaptureRequest.SCALER_CROP_REGION, this.mCropRegion);
}
}
应用新的计算缩放的代码 fragment :
yourCameraSession.setRepeatingRequest(builder.build(), yourPreviewOrCaptureSessionCallback, yourCameraThreadHandler);
关于java - 使用Camera2 API设置相机变焦,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/52568987/