boofcv.alg.background

Class BackgroundModelMoving<T extends ImageBase,MotionModel extends InvertibleTransform<MotionModel>>

java.lang.Object

boofcv.alg.background.BackgroundModel<T>

boofcv.alg.background.BackgroundModelMoving<T,MotionModel>

Direct Known Subclasses:

BackgroundMovingBasic, BackgroundMovingGaussian

public abstract class BackgroundModelMoving<T extends ImageBase,MotionModel extends InvertibleTransform<MotionModel>>
extends BackgroundModel<T>

Base class for classifying pixels and background based on the apparent motion of pixels when the camera is moving. The camera motion is provided externally.

There are three coordinate systems.

1. World is the background model's coordinate system.
2. Home is the image which all the camera motion is relative to
3. Current is the location of the current image.

The background model is composed of a single fixed sized image. The background image size is specified in the initialize(int, int, InvertibleTransform) function. After that the background model is updated by calling updateBackground(InvertibleTransform, ImageBase). To flag pixels as background/motion call segment(InvertibleTransform, ImageBase, GrayU8).

If a pixel in the current frame has no corresponding pixel in the background or the background pixel hasn't been observed yet then it will be assigned a special value, which is user configurable. The default value is 0, which is a background pixel. See BackgroundModel.setUnknownValue(int)}

Constructor Summary

Constructors

Constructor and Description
BackgroundModelMoving(PointTransformModel_F32<MotionModel> transform, ImageType<T> imageType) Constructor which provides the motion model and image type

Method Summary

Modifier and Type	Method and Description
abstract void	initialize(int backgroundWidth, int backgroundHeight, MotionModel homeToWorld) Initializes background model.
void	segment(MotionModel homeToCurrent, T frame, GrayU8 segmented) Invoke to use the background image to segment the current frame into background and foreground pixels
void	updateBackground(MotionModel homeToCurrent, T frame) Updates the background with new image information.

Methods inherited from class boofcv.alg.background.BackgroundModel

getImageType, getUnknownValue, reset, setUnknownValue

Methods inherited from class java.lang.Object

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

Constructor Detail

BackgroundModelMoving

public BackgroundModelMoving(PointTransformModel_F32<MotionModel> transform,
                             ImageType<T> imageType)

Constructor which provides the motion model and image type

Parameters:

transform - Point transform which can be used to apply the motion model

imageType - Type of input image

Method Detail

initialize

public abstract void initialize(int backgroundWidth,
                                int backgroundHeight,
                                MotionModel homeToWorld)

Initializes background model. Specifies the size of the background image and transform from the "home" image to the background "world"

Parameters:

backgroundWidth - Width of background

backgroundHeight - Height of background

homeToWorld - Transform from home to world.

updateBackground

public void updateBackground(MotionModel homeToCurrent,
                             T frame)

Updates the background with new image information.

Parameters:

homeToCurrent - Transform from home image to the current image

frame - The current image in the sequence

segment

public void segment(MotionModel homeToCurrent,
                    T frame,
                    GrayU8 segmented)

Invoke to use the background image to segment the current frame into background and foreground pixels

Parameters:

homeToCurrent - Transform from home image to the current image

frame - current image

segmented - Segmented image. 0 = background, 1 = foreground/moving