net.doo.snap.camera

Class ContourDetectorFrameHandler

java.lang.Object

net.doo.snap.camera.ContourDetectorFrameHandler

All Implemented Interfaces:

PreviewBuffer.FrameHandler

public class ContourDetectorFrameHandler
extends java.lang.Object
implements PreviewBuffer.FrameHandler

Performs contour detection on camera preview frames. Outputs results via ContourDetectorFrameHandler.ResultHandler (addResultHandler(ResultHandler)).

Preview frame considered intercepted if at least one ContourDetectorFrameHandler.ResultHandler returns true from net.doo.snap.camera.ContourDetectorFrameHandler.ResultHandler#handleResult(DetectedFrame)

See Also:

PreviewBuffer

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ContourDetectorFrameHandler.DetectedFrame Contour detection results alongside with information about frame
static interface	ContourDetectorFrameHandler.ResultHandler Continiously notified about contour detection results.

Constructor Summary

Constructors

Constructor and Description
ContourDetectorFrameHandler(android.content.Context context)

Method Summary

Modifier and Type	Method and Description
void	addResultHandler(ContourDetectorFrameHandler.ResultHandler handler) Registers result handler which will be notified about contour detection results.
static ContourDetectorFrameHandler	attach(ScanbotCameraView cameraView) Convenience method for creating new ContourDetectorFrameHandler and adding it as PreviewBuffer.FrameHandler to given camera view.
boolean	handleFrame(byte[] frame, int width, int height, int frameOrientation) Invoked for every new camera preview frame
boolean	isEnabled()
void	removeResultHandler(ContourDetectorFrameHandler.ResultHandler handler) Unregisters handler.
void	setAcceptedAngleScore(double acceptedAngleScore) The minimum score in percent (0 - 100) of the perspective distortion to accept a detected document.
void	setAcceptedSizeScore(double acceptedSizeScore) The minimum size in percent (0 - 100) of the screen size to accept a detected document.
void	setEnabled(boolean enabled)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ContourDetectorFrameHandler

public ContourDetectorFrameHandler(android.content.Context context)

Method Detail

attach

public static ContourDetectorFrameHandler attach(ScanbotCameraView cameraView)

Convenience method for creating new ContourDetectorFrameHandler and adding it as PreviewBuffer.FrameHandler to given camera view.

Parameters:

cameraView - camera view to which new contour detector will be attached

Returns:

new ContourDetectorFrameHandler

handleFrame

public boolean handleFrame(byte[] frame,
                           int width,
                           int height,
                           int frameOrientation)

Description copied from interface: PreviewBuffer.FrameHandler

Invoked for every new camera preview frame

Specified by:

handleFrame in interface PreviewBuffer.FrameHandler

Parameters:

frame - image in NV21 format

width - width of the image

height - height of the image

frameOrientation - orientation of the image (in degrees)

Returns:

true if frame should be considered as "intercepted", i.e. no further processing should be performed on it. false to allow other frame handlers to process this frame.

addResultHandler

public void addResultHandler(ContourDetectorFrameHandler.ResultHandler handler)

Registers result handler which will be notified about contour detection results.

Results are coming on the worker thread. Don't forget to move execution to main thread before updating UI.

Parameters:

handler - handler to register. Must not be null. If handler was already registered, nothing happens.

removeResultHandler

public void removeResultHandler(ContourDetectorFrameHandler.ResultHandler handler)

Unregisters handler.

Parameters:

handler - handler to unregister. If it was not registered before, nothing happens.

isEnabled

public boolean isEnabled()

Returns:

true if contour detection is enabled. false if contour detection is disabled, i.e. incoming frames are skipped.

setEnabled

public void setEnabled(boolean enabled)

Parameters:

enabled - true to enable contour detection. false to disable contour detection.

setAcceptedAngleScore

public final void setAcceptedAngleScore(double acceptedAngleScore)

The minimum score in percent (0 - 100) of the perspective distortion to accept a detected document. Default is 75.0. Set lower values to accept more perspective distortion. Warning: Lower values result in more blurred document images.

Parameters:

acceptedAngleScore -

setAcceptedSizeScore

public final void setAcceptedSizeScore(double acceptedSizeScore)

The minimum size in percent (0 - 100) of the screen size to accept a detected document. It is sufficient that height or width match the score. Default is 80.0. Warning: Lower values result in low resolution document images.

Parameters:

acceptedSizeScore -