CameraBridgeViewBase (OpenCV 2.4.3 (RC) Java API)

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OpenCV 2.4.3 (RC)

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org.opencv.android
Class CameraBridgeViewBase

java.lang.Object
 extended by SurfaceView
 extended by org.opencv.android.CameraBridgeViewBase

Direct Known Subclasses:: JavaCameraView, NativeCameraView

public abstract class CameraBridgeViewBase
extends SurfaceView
extends SurfaceView

This is a basic class, implementing the interaction with Camera and OpenCV library. The main responsibility of it - is to control when camera can be enabled, process the frame, call external listener to make any adjustments to the frame and then draw the resulting frame to the screen. The clients shall implement CvCameraViewListener TODO: add method to control the format in which the frames will be delivered to CvCameraViewListener

Nested Class Summary
`static interface`	`CameraBridgeViewBase.CvCameraViewListener`
`static interface`	`CameraBridgeViewBase.ListItemAccessor`

Field Summary
`protected int`	`mFrameHeight`
`protected int`	`mFrameWidth`
`protected int`	`mMaxHeight`
`protected int`	`mMaxWidth`
`protected int`	`mPreviewFormat`

Constructor Summary
`CameraBridgeViewBase(Context context, AttributeSet attrs)`

Method Summary
`protected void`	`AllocateCache()`
`protected Size`	`calculateCameraFrameSize(java.util.List<?> supportedSizes, CameraBridgeViewBase.ListItemAccessor accessor, int surfaceWidth, int surfaceHeight)` This helper method can be called by subclasses to select camera preview size.
`protected abstract boolean`	`connectCamera(int width, int height)` This method is invoked shall perform concrete operation to initialize the camera.
`protected void`	`deliverAndDrawFrame(Mat frame)` This method shall be called by the subclasses when they have valid object and want it to be delivered to external client (via callback) and then displayed on the screen.
`void`	`disableView()` This method is provided for clients, so they can disable camera connection and stop the delivery of frames even though the surface view itself is not destroyed and still stays on the scren
`protected abstract void`	`disconnectCamera()` Disconnects and release the particular camera object being connected to this surface view.
`void`	`enableView()` This method is provided for clients, so they can enable the camera connection.
`void`	`SetCaptureFormat(int format)`
`void`	`setCvCameraViewListener(CameraBridgeViewBase.CvCameraViewListener listener)`
`void`	`setMaxFrameSize(int maxWidth, int maxHeight)` This method sets the maximum size that camera frame is allowed to be.
`void`	`surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3)`
`void`	`surfaceCreated(SurfaceHolder holder)`
`void`	`surfaceDestroyed(SurfaceHolder holder)`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Field Detail

mFrameHeight

protected int mFrameHeight

mFrameWidth

protected int mFrameWidth

mMaxHeight

protected int mMaxHeight

mMaxWidth

protected int mMaxWidth

mPreviewFormat

protected int mPreviewFormat

Constructor Detail

CameraBridgeViewBase

public CameraBridgeViewBase(Context context,
 AttributeSet attrs)

Method Detail

AllocateCache

protected void AllocateCache()

calculateCameraFrameSize

protected Size calculateCameraFrameSize(java.util.List<?> supportedSizes,
 CameraBridgeViewBase.ListItemAccessor accessor,
 int surfaceWidth,
 int surfaceHeight)

This helper method can be called by subclasses to select camera preview size. It goes over the list of the supported preview sizes and selects the maximum one which fits both values set via setMaxFrameSize() and surface frame allocated for this view

Parameters:: supportedSizes -; surfaceWidth -; surfaceHeight -
Returns:

connectCamera

protected abstract boolean connectCamera(int width,
 int height)

This method is invoked shall perform concrete operation to initialize the camera. CONTRACT: as a result of this method variables mFrameWidth and mFrameHeight MUST be initialized with the size of the Camera frames that will be delivered to external processor.

Parameters:: width - - the width of this SurfaceView; height - - the height of this SurfaceView

deliverAndDrawFrame

protected void deliverAndDrawFrame(Mat frame)

This method shall be called by the subclasses when they have valid object and want it to be delivered to external client (via callback) and then displayed on the screen.

Parameters:: frame - - the current frame to be delivered

disableView

public void disableView()

This method is provided for clients, so they can disable camera connection and stop the delivery of frames even though the surface view itself is not destroyed and still stays on the scren

disconnectCamera

protected abstract void disconnectCamera()

Disconnects and release the particular camera object being connected to this surface view. Called when syncObject lock is held

enableView

public void enableView()

This method is provided for clients, so they can enable the camera connection. The actual onCameraViewStarted callback will be delivered only after both this method is called and surface is available

SetCaptureFormat

public void SetCaptureFormat(int format)

setCvCameraViewListener

public void setCvCameraViewListener(CameraBridgeViewBase.CvCameraViewListener listener)

setMaxFrameSize

public void setMaxFrameSize(int maxWidth,
 int maxHeight)

This method sets the maximum size that camera frame is allowed to be. When selecting size - the biggest size which less or equal the size set will be selected. As an example - we set setMaxFrameSize(200,200) and we have 176x152 and 320x240 sizes. The preview frame will be selected with 176x152 size. This method is useful when need to restrict the size of preview frame for some reason (for example for video recording)

Parameters:: maxWidth - - the maximum width allowed for camera frame.; maxHeight - - the maximum height allowed for camera frame

surfaceChanged

public void surfaceChanged(SurfaceHolder arg0,
 int arg1,
 int arg2,
 int arg3)

surfaceCreated

public void surfaceCreated(SurfaceHolder holder)

surfaceDestroyed

public void surfaceDestroyed(SurfaceHolder holder)