BroxWarpingSpacial (feature 0.23 API)

java.lang.Object
- boofcv.alg.flow.DenseFlowPyramidBase<T>
- - boofcv.alg.flow.BroxWarpingSpacial<T>

```
public class BroxWarpingSpacial<T extends boofcv.struct.image.ImageGray>
extends DenseFlowPyramidBase<T>
```
Dense optical flow which adheres to a brightness constancy assumption, a gradient constancy assumption, and a discontinuity-preserving spatio-temporal smoothness constraint. Based on the work of Brox [2] with implementation details taken from [1].
1. Javier Sánchez Pérez, Nelson Monzón López, and Agustín Salgado de la Nuez, Robust Optical Flow Estimation, Image Processing On Line, 3 (2013), pp. 252–270. http://dx.doi.org/10.5201/ipol.2013.21
2. Thomas Brox, Andr´es Bruhn, Nils Papenberg, and Joachim Weickert. High accuracy optical ﬂow estimation based on a theory for warping. In T. Pajdla and J. Matas, editors, European Conference on Computer Vision (ECCV), volume 3024 of Lecture Notes in Computer Science, pages 25–36, Prague, Czech Republic, May 2004. Springer.

Field Summary

Fields
Modifier and Type	Field and Description
`protected float`	`alpha`
`protected boofcv.struct.image.GrayF32`	`derivFlowUX`
`protected boofcv.struct.image.GrayF32`	`derivFlowUY`
`protected boofcv.struct.image.GrayF32`	`derivFlowVX`
`protected boofcv.struct.image.GrayF32`	`derivFlowVY`
`protected boofcv.struct.image.GrayF32`	`divD`
`protected boofcv.struct.image.GrayF32`	`divU`
`protected boofcv.struct.image.GrayF32`	`divV`
`protected boofcv.struct.image.GrayF32`	`du`
`protected boofcv.struct.image.GrayF32`	`dv`
`protected boofcv.struct.image.GrayF32`	`flowU`
`protected boofcv.struct.image.GrayF32`	`flowV`
`protected float`	`gamma`
`protected boofcv.struct.image.GrayF32`	`psiData`
`protected boofcv.struct.image.GrayF32`	`psiGradient`
`protected boofcv.struct.image.GrayF32`	`psiSmooth`
`protected boofcv.struct.image.GrayF32`	`warpDeriv2X`
`protected boofcv.struct.image.GrayF32`	`warpDeriv2XX`
`protected boofcv.struct.image.GrayF32`	`warpDeriv2XY`
`protected boofcv.struct.image.GrayF32`	`warpDeriv2Y`
`protected boofcv.struct.image.GrayF32`	`warpDeriv2YY`
`protected boofcv.struct.image.GrayF32`	`warpImage2`

Fields inherited from class boofcv.alg.flow.DenseFlowPyramidBase
interp, pyr1, pyr2

Constructor Summary

Constructors
Constructor and Description
`BroxWarpingSpacial(ConfigBroxWarping config, boofcv.alg.interpolate.InterpolatePixelS<boofcv.struct.image.GrayF32> interp)` Configures flow estimation

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`protected void`	`computeDivUVD_safe(int x, int y, boofcv.struct.image.GrayF32 u, boofcv.struct.image.GrayF32 v, boofcv.struct.image.GrayF32 psi, boofcv.struct.image.GrayF32 divU, boofcv.struct.image.GrayF32 divV, boofcv.struct.image.GrayF32 divD)`
`protected void`	computePsiDataPsiGradient(boofcv.struct.image.GrayF32 image1, boofcv.struct.image.GrayF32 image2, boofcv.struct.image.GrayF32 deriv1x, boofcv.struct.image.GrayF32 deriv1y, boofcv.struct.image.GrayF32 deriv2x, boofcv.struct.image.GrayF32 deriv2y, boofcv.struct.image.GrayF32 deriv2xx, boofcv.struct.image.GrayF32 deriv2yy, boofcv.struct.image.GrayF32 deriv2xy, boofcv.struct.image.GrayF32 du, boofcv.struct.image.GrayF32 dv, boofcv.struct.image.GrayF32 psiData, boofcv.struct.image.GrayF32 psiGradient) Compute Psi-data using equation 6 and approximation in equation 5
`boofcv.struct.image.GrayF32`	`getFlowX()`
`boofcv.struct.image.GrayF32`	`getFlowY()`
`protected void`	`interpolateFlowScale(int widthNew, int heightNew)` Provides an initial estimate for the flow by interpolating values from the previous layer.
`void`	`process(boofcv.struct.pyramid.ImagePyramid<boofcv.struct.image.GrayF32> image1, boofcv.struct.pyramid.ImagePyramid<boofcv.struct.image.GrayF32> image2)` Computes dense optical flow from the provided image pyramid.
`protected void`	`processLayer(boofcv.struct.image.GrayF32 image1, boofcv.struct.image.GrayF32 image2, boofcv.struct.image.GrayF32 deriv1X, boofcv.struct.image.GrayF32 deriv1Y, boofcv.struct.image.GrayF32 deriv2X, boofcv.struct.image.GrayF32 deriv2Y, boofcv.struct.image.GrayF32 deriv2XX, boofcv.struct.image.GrayF32 deriv2YY, boofcv.struct.image.GrayF32 deriv2XY)` Computes the flow for a layer using Taylor series expansion and Successive Over-Relaxation linear solver.
`protected void`	`resizeForLayer(int width, int height)` Resize images for the current layer being processed
`protected int`	`s(int x, int y)`

Methods inherited from class boofcv.alg.flow.DenseFlowPyramidBase
imageNormalization, interpolateFlowScale, process, warpImageTaylor

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

Field Detail

alpha
```
protected float alpha
```

gamma
```
protected float gamma
```

flowU

protected boofcv.struct.image.GrayF32 flowU

flowV

protected boofcv.struct.image.GrayF32 flowV

warpImage2

protected boofcv.struct.image.GrayF32 warpImage2

warpDeriv2X

protected boofcv.struct.image.GrayF32 warpDeriv2X

warpDeriv2Y

protected boofcv.struct.image.GrayF32 warpDeriv2Y

warpDeriv2XX

protected boofcv.struct.image.GrayF32 warpDeriv2XX

warpDeriv2YY

protected boofcv.struct.image.GrayF32 warpDeriv2YY

warpDeriv2XY

protected boofcv.struct.image.GrayF32 warpDeriv2XY

derivFlowUX

protected boofcv.struct.image.GrayF32 derivFlowUX

derivFlowUY

protected boofcv.struct.image.GrayF32 derivFlowUY

derivFlowVX

protected boofcv.struct.image.GrayF32 derivFlowVX

derivFlowVY

protected boofcv.struct.image.GrayF32 derivFlowVY

psiSmooth

protected boofcv.struct.image.GrayF32 psiSmooth

psiData

protected boofcv.struct.image.GrayF32 psiData

psiGradient

protected boofcv.struct.image.GrayF32 psiGradient

divU

protected boofcv.struct.image.GrayF32 divU

divV

protected boofcv.struct.image.GrayF32 divV

divD

protected boofcv.struct.image.GrayF32 divD

du

protected boofcv.struct.image.GrayF32 du

dv

protected boofcv.struct.image.GrayF32 dv

Constructor Detail
- BroxWarpingSpacial
```
public BroxWarpingSpacial(ConfigBroxWarping config,
                          boofcv.alg.interpolate.InterpolatePixelS<boofcv.struct.image.GrayF32> interp)
```
  Configures flow estimation
  
  Parameters:
  
  config - Configuration parameters
  
  interp - Interpolation for image flow between image layers and warping. Overrides selection in config.

Method Detail

process
```
public void process(boofcv.struct.pyramid.ImagePyramid<boofcv.struct.image.GrayF32> image1,
                    boofcv.struct.pyramid.ImagePyramid<boofcv.struct.image.GrayF32> image2)
```
Computes dense optical flow from the provided image pyramid. Image gradient for each layer should be computed directly from the layer images.

Specified by:

process in class DenseFlowPyramidBase<T extends boofcv.struct.image.ImageGray>

Parameters:

image1 - Pyramid of first image

image2 - Pyramid of second image

resizeForLayer

protected void resizeForLayer(int width,
                              int height)

Resize images for the current layer being processed

interpolateFlowScale
```
protected void interpolateFlowScale(int widthNew,
                                    int heightNew)
```
Provides an initial estimate for the flow by interpolating values from the previous layer.

processLayer

protected void processLayer(boofcv.struct.image.GrayF32 image1,
                            boofcv.struct.image.GrayF32 image2,
                            boofcv.struct.image.GrayF32 deriv1X,
                            boofcv.struct.image.GrayF32 deriv1Y,
                            boofcv.struct.image.GrayF32 deriv2X,
                            boofcv.struct.image.GrayF32 deriv2Y,
                            boofcv.struct.image.GrayF32 deriv2XX,
                            boofcv.struct.image.GrayF32 deriv2YY,
                            boofcv.struct.image.GrayF32 deriv2XY)

Computes the flow for a layer using Taylor series expansion and Successive Over-Relaxation linear solver. Flow estimates from previous layers are feed into this by setting initFlow and flow to their values.

computePsiDataPsiGradient

protected void computePsiDataPsiGradient(boofcv.struct.image.GrayF32 image1,
                                         boofcv.struct.image.GrayF32 image2,
                                         boofcv.struct.image.GrayF32 deriv1x,
                                         boofcv.struct.image.GrayF32 deriv1y,
                                         boofcv.struct.image.GrayF32 deriv2x,
                                         boofcv.struct.image.GrayF32 deriv2y,
                                         boofcv.struct.image.GrayF32 deriv2xx,
                                         boofcv.struct.image.GrayF32 deriv2yy,
                                         boofcv.struct.image.GrayF32 deriv2xy,
                                         boofcv.struct.image.GrayF32 du,
                                         boofcv.struct.image.GrayF32 dv,
                                         boofcv.struct.image.GrayF32 psiData,
                                         boofcv.struct.image.GrayF32 psiGradient)

Compute Psi-data using equation 6 and approximation in equation 5

computeDivUVD_safe

protected void computeDivUVD_safe(int x,
                                  int y,
                                  boofcv.struct.image.GrayF32 u,
                                  boofcv.struct.image.GrayF32 v,
                                  boofcv.struct.image.GrayF32 psi,
                                  boofcv.struct.image.GrayF32 divU,
                                  boofcv.struct.image.GrayF32 divV,
                                  boofcv.struct.image.GrayF32 divD)

s

protected int s(int x,
                int y)

getFlowX

public boofcv.struct.image.GrayF32 getFlowX()

getFlowY

public boofcv.struct.image.GrayF32 getFlowY()

Class BroxWarpingSpacial<T extends boofcv.struct.image.ImageGray>