| OpenCV 3.4.1 Open Source Computer Vision

Classes | Enumerations | Functions
Filters
Extended Image Processing

## Classes
class | cv::ximgproc::AdaptiveManifoldFilter
| Interface for Adaptive Manifold Filter realizations. More...
class | cv::ximgproc::DisparityFilter
| Main interface for all disparity map filters. More...
class | cv::ximgproc::DisparityWLSFilter
| Disparity map filter based on Weighted Least Squares filter (in form of Fast Global Smoother that is a lot faster than traditional Weighted Least Squares filter implementations) and optional use of left-right-consistency-based confidence to refine the results in half-occlusions and uniform areas. More...
class | cv::ximgproc::DTFilter
| Interface for realizations of Domain Transform filter. More...
class | cv::ximgproc::EdgeAwareInterpolator
| Sparse match interpolation algorithm based on modified locally-weighted affine estimator from [152] and Fast Global Smoother as post-processing filter. More...
class | cv::ximgproc::FastGlobalSmootherFilter
| Interface for implementations of Fast Global Smoother filter. More...
class | cv::ximgproc::GuidedFilter
| Interface for realizations of Guided Filter. More...
class | cv::ximgproc::RidgeDetectionFilter
| Applies Ridge Detection Filter to an input image. Implements Ridge detection similar to the one in Mathematica using the eigen values from the Hessian Matrix of the input image using Sobel Derivatives. Additional refinement can be done using Skeletonization and Binarization. More...
class | cv::ximgproc::SparseMatchInterpolator
| Main interface for all filters, that take sparse matches as an input and produce a dense per-pixel matching (optical flow) as an output. More...

## Enumerations
enum | cv::ximgproc::EdgeAwareFiltersList { cv::ximgproc::DTF_NC, cv::ximgproc::DTF_IC, cv::ximgproc::DTF_RF, cv::ximgproc::GUIDED_FILTER, cv::ximgproc::AM_FILTER }

## Functions
void | cv::ximgproc::amFilter (InputArray joint, InputArray src, OutputArray dst, double sigma_s, double sigma_r, bool adjust_outliers=false)
| Simple one-line Adaptive Manifold Filter call. More...
void | cv::ximgproc::bilateralTextureFilter (InputArray src, OutputArray dst, int fr=3, int numIter=1, double sigmaAlpha=-1., double sigmaAvg=-1.)
| Applies the bilateral texture filter to an image. It performs structure-preserving texture filter. For more details about this filter see [34]. More...
double | cv::ximgproc::computeBadPixelPercent (InputArray GT, InputArray src, Rect ROI, int thresh=24)
| Function for computing the percent of "bad" pixels in the disparity map (pixels where error is higher than a specified threshold) More...
double | cv::ximgproc::computeMSE (InputArray GT, InputArray src, Rect ROI)
| Function for computing mean square error for disparity maps. More...
Ptr< AdaptiveManifoldFilter > | cv::ximgproc::createAMFilter (double sigma_s, double sigma_r, bool adjust_outliers=false)
| Factory method, create instance of AdaptiveManifoldFilter and produce some initialization routines. More...
Ptr< DisparityWLSFilter > | cv::ximgproc::createDisparityWLSFilter (Ptr< StereoMatcher > matcher_left)
| Convenience factory method that creates an instance of DisparityWLSFilter and sets up all the relevant filter parameters automatically based on the matcher instance. Currently supports only StereoBM and StereoSGBM. More...
Ptr< DisparityWLSFilter > | cv::ximgproc::createDisparityWLSFilterGeneric (bool use_confidence)
| More generic factory method, create instance of DisparityWLSFilter and execute basic initialization routines. When using this method you will need to set-up the ROI, matchers and other parameters by yourself. More...
Ptr< DTFilter > | cv::ximgproc::createDTFilter (InputArray guide, double sigmaSpatial, double sigmaColor, int mode=DTF_NC, int numIters=3)
| Factory method, create instance of DTFilter and produce initialization routines. More...
Ptr< EdgeAwareInterpolator > | cv::ximgproc::createEdgeAwareInterpolator ()
| Factory method that creates an instance of the EdgeAwareInterpolator. More...
Ptr< FastGlobalSmootherFilter > | cv::ximgproc::createFastGlobalSmootherFilter (InputArray guide, double lambda, double sigma_color, double lambda_attenuation=0.25, int num_iter=3)
| Factory method, create instance of FastGlobalSmootherFilter and execute the initialization routines. More...
Ptr< GuidedFilter > | cv::ximgproc::createGuidedFilter (InputArray guide, int radius, double eps)
| Factory method, create instance of GuidedFilter and produce initialization routines. More...
Ptr< StereoMatcher > | cv::ximgproc::createRightMatcher (Ptr< StereoMatcher > matcher_left)
| Convenience method to set up the matcher for computing the right-view disparity map that is required in case of filtering with confidence. More...
void | cv::ximgproc::dtFilter (InputArray guide, InputArray src, OutputArray dst, double sigmaSpatial, double sigmaColor, int mode=DTF_NC, int numIters=3)
| Simple one-line Domain Transform filter call. If you have multiple images to filter with the same guided image then use DTFilter interface to avoid extra computations on initialization stage. More...
void | cv::ximgproc::fastGlobalSmootherFilter (InputArray guide, InputArray src, OutputArray dst, double lambda, double sigma_color, double lambda_attenuation=0.25, int num_iter=3)
| Simple one-line Fast Global Smoother filter call. If you have multiple images to filter with the same guide then use FastGlobalSmootherFilter interface to avoid extra computations. More...
void | cv::ximgproc::getDisparityVis (InputArray src, OutputArray dst, double scale=1.0)
| Function for creating a disparity map visualization (clamped CV_8U image) More...
void | cv::ximgproc::GradientDericheX (InputArray _op, OutputArray _dst, double alphaDerive, double alphaMean)
| Applies X Deriche filter to an image. More...
void | cv::ximgproc::GradientDericheY (InputArray _op, OutputArray _dst, double alphaDerive, double alphaMean)
| Applies Y Deriche filter to an image. More...
void | cv::ximgproc::GradientPaillouX (InputArray op, OutputArray _dst, double alpha, double omega)
void | cv::ximgproc::GradientPaillouY (InputArray op, OutputArray _dst, double alpha, double omega)
| Applies Paillou filter to an image. More...
void | cv::ximgproc::guidedFilter (InputArray guide, InputArray src, OutputArray dst, int radius, double eps, int dDepth=-1)
| Simple one-line Guided Filter call. More...
void | cv::ximgproc::jointBilateralFilter (InputArray joint, InputArray src, OutputArray dst, int d, double sigmaColor, double sigmaSpace, int borderType=BORDER_DEFAULT)
| Applies the joint bilateral filter to an image. More...
void | cv::ximgproc::l0Smooth (InputArray src, OutputArray dst, double lambda=0.02, double kappa=2.0)
| Global image smoothing via L0 gradient minimization. More...
int | cv::ximgproc::readGT (String src_path, OutputArray dst)
| Function for reading ground truth disparity maps. Supports basic Middlebury and MPI-Sintel formats. Note that the resulting disparity map is scaled by 16. More...
void | cv::ximgproc::rollingGuidanceFilter (InputArray src, OutputArray dst, int d=-1, double sigmaColor=25, double sigmaSpace=3, int numOfIter=4, int borderType=BORDER_DEFAULT)
| Applies the rolling guidance filter to an image. More...

## Detailed Description

## Enumeration Type Documentation

## § EdgeAwareFiltersList

enum cv::ximgproc::EdgeAwareFiltersList

Enumerator
DTF_NC Python: cv.ximgproc.DTF_NC |
DTF_IC Python: cv.ximgproc.DTF_IC |
DTF_RF Python: cv.ximgproc.DTF_RF |
GUIDED_FILTER Python: cv.ximgproc.GUIDED_FILTER |
AM_FILTER Python: cv.ximgproc.AM_FILTER |

## Function Documentation

## § amFilter()

void cv::ximgproc::amFilter | ( | InputArray | joint,
|  | InputArray | src,
|  | OutputArray | dst,
|  | double | sigma_s,
|  | double | sigma_r,
|  | bool | adjust_outliers = `false`
| ) |  |

Python:
| dst | = | cv.ximgproc.amFilter( | joint, src, sigma_s, sigma_r[, dst[, adjust_outliers]] | )

Simple one-line Adaptive Manifold Filter call.

Parameters

  joint | joint (also called as guided) image or array of images with any numbers of channels.
  src | filtering image with any numbers of channels.
  dst | output image.
  sigma_s | spatial standard deviation.
  sigma_r | color space standard deviation, it is similar to the sigma in the color space into bilateralFilter.
  adjust_outliers | optional, specify perform outliers adjust operation or not, (Eq. 9) in the original paper.

Note
  Joint images with CV_8U and CV_16U depth converted to images with CV_32F depth and [0; 1] color range before processing. Hence color space sigma sigma_r must be in [0; 1] range, unlike same sigmas in bilateralFilter and dtFilter functions.

See also
  bilateralFilter, dtFilter, guidedFilter

## § bilateralTextureFilter()

void cv::ximgproc::bilateralTextureFilter | ( | InputArray | src,
|  | OutputArray | dst,
|  | int | fr = `3`,
|  | int | numIter = `1`,
|  | double | sigmaAlpha = `-1.`,
|  | double | sigmaAvg = `-1.`
| ) |  |

Python:
| dst | = | cv.ximgproc.bilateralTextureFilter( | src[, dst[, fr[, numIter[, sigmaAlpha[, sigmaAvg]]]]] | )

Applies the bilateral texture filter to an image. It performs structure-preserving texture filter. For more details about this filter see [34].

Parameters

  src | Source image whose depth is 8-bit UINT or 32-bit FLOAT
  dst | Destination image of the same size and type as src.
  fr | Radius of kernel to be used for filtering. It should be positive integer
  numIter | Number of iterations of algorithm, It should be positive integer
  sigmaAlpha | Controls the sharpness of the weight transition from edges to smooth/texture regions, where a bigger value means sharper transition. When the value is negative, it is automatically calculated.
  sigmaAvg | Range blur parameter for texture blurring. Larger value makes result to be more blurred. When the value is negative, it is automatically calculated as described in the paper.

See also
  rollingGuidanceFilter, bilateralFilter

## § computeBadPixelPercent()

double cv::ximgproc::computeBadPixelPercent | ( | InputArray | GT,
|  | InputArray | src,
|  | Rect | ROI,
|  | int | thresh = `24`
| ) |  |

Function for computing the percent of "bad" pixels in the disparity map (pixels where error is higher than a specified threshold)

Parameters

  GT | ground truth disparity map
  src | disparity map to evaluate
  ROI | region of interest
  thresh | threshold used to determine "bad" pixels

Returns
  returns mean square error between GT and src

## § computeMSE()

double cv::ximgproc::computeMSE | ( | InputArray | GT,
|  | InputArray | src,
|  | Rect | ROI
| ) |  |

Function for computing mean square error for disparity maps.

Parameters

  GT | ground truth disparity map
  src | disparity map to evaluate
  ROI | region of interest

Returns
  returns mean square error between GT and src

## § createAMFilter()

Ptr<AdaptiveManifoldFilter> cv::ximgproc::createAMFilter | ( | double | sigma_s,
|  | double | sigma_r,
|  | bool | adjust_outliers = `false`
| ) |  |

Python:
| retval | = | cv.ximgproc.createAMFilter( | sigma_s, sigma_r[, adjust_outliers] | )

Factory method, create instance of AdaptiveManifoldFilter and produce some initialization routines.

Parameters

  sigma_s | spatial standard deviation.
  sigma_r | color space standard deviation, it is similar to the sigma in the color space into bilateralFilter.
  adjust_outliers | optional, specify perform outliers adjust operation or not, (Eq. 9) in the original paper.

For more details about Adaptive Manifold Filter parameters, see the original article [65] .

Note
  Joint images with CV_8U and CV_16U depth converted to images with CV_32F depth and [0; 1] color range before processing. Hence color space sigma sigma_r must be in [0; 1] range, unlike same sigmas in bilateralFilter and dtFilter functions.

## § createDisparityWLSFilter()

Ptr<DisparityWLSFilter> cv::ximgproc::createDisparityWLSFilter | ( | Ptr< StereoMatcher > | matcher_left | ) |

Python:
| retval | = | cv.ximgproc.createDisparityWLSFilter( | matcher_left | )

Convenience factory method that creates an instance of DisparityWLSFilter and sets up all the relevant filter parameters automatically based on the matcher instance. Currently supports only StereoBM and StereoSGBM.

Parameters

  matcher_left | stereo matcher instance that will be used with the filter

## § createDisparityWLSFilterGeneric()

Ptr<DisparityWLSFilter> cv::ximgproc::createDisparityWLSFilterGeneric | ( | bool | use_confidence | ) |

Python:
| retval | = | cv.ximgproc.createDisparityWLSFilterGeneric( | use_confidence | )

More generic factory method, create instance of DisparityWLSFilter and execute basic initialization routines. When using this method you will need to set-up the ROI, matchers and other parameters by yourself.

Parameters

  use_confidence | filtering with confidence requires two disparity maps (for the left and right views) and is approximately two times slower. However, quality is typically significantly better.

## § createDTFilter()

Ptr<DTFilter> cv::ximgproc::createDTFilter | ( | InputArray | guide,
|  | double | sigmaSpatial,
|  | double | sigmaColor,
|  | int | mode = `DTF_NC`,
|  | int | numIters = `3`
| ) |  |

Python:
| retval | = | cv.ximgproc.createDTFilter( | guide, sigmaSpatial, sigmaColor[, mode[, numIters]] | )

Factory method, create instance of DTFilter and produce initialization routines.

Parameters

  guide | guided image (used to build transformed distance, which describes edge structure of guided image).
  sigmaSpatial | \({\sigma}_H\) parameter in the original article, it's similar to the sigma in the coordinate space into bilateralFilter.
  sigmaColor | \({\sigma}_r\) parameter in the original article, it's similar to the sigma in the color space into bilateralFilter.
  mode | one form three modes DTF_NC, DTF_RF and DTF_IC which corresponds to three modes for filtering 2D signals in the article.
  numIters | optional number of iterations used for filtering, 3 is quite enough.

For more details about Domain Transform filter parameters, see the original article [64] and Domain Transform filter homepage.

## § createEdgeAwareInterpolator()

Ptr<EdgeAwareInterpolator> cv::ximgproc::createEdgeAwareInterpolator | ( |  | ) |

Python:
| retval | = | cv.ximgproc.createEdgeAwareInterpolator( |  | )

Factory method that creates an instance of the EdgeAwareInterpolator.

## § createFastGlobalSmootherFilter()

Ptr<FastGlobalSmootherFilter> cv::ximgproc::createFastGlobalSmootherFilter | ( | InputArray | guide,
|  | double | lambda,
|  | double | sigma_color,
|  | double | lambda_attenuation = `0.25`,
|  | int | num_iter = `3`
| ) |  |

Python:
| retval | = | cv.ximgproc.createFastGlobalSmootherFilter( | guide, lambda, sigma_color[, lambda_attenuation[, num_iter]] | )

Factory method, create instance of FastGlobalSmootherFilter and execute the initialization routines.

Parameters

  guide | image serving as guide for filtering. It should have 8-bit depth and either 1 or 3 channels.
  lambda | parameter defining the amount of regularization
  sigma_color | parameter, that is similar to color space sigma in bilateralFilter.
  lambda_attenuation | internal parameter, defining how much lambda decreases after each iteration. Normally, it should be 0.25. Setting it to 1.0 may lead to streaking artifacts.
  num_iter | number of iterations used for filtering, 3 is usually enough.

For more details about Fast Global Smoother parameters, see the original paper [129]. However, please note that there are several differences. Lambda attenuation described in the paper is implemented a bit differently so do not expect the results to be identical to those from the paper; sigma_color values from the paper should be multiplied by 255.0 to achieve the same effect. Also, in case of image filtering where source and guide image are the same, authors propose to dynamically update the guide image after each iteration. To maximize the performance this feature was not implemented here.

## § createGuidedFilter()

Ptr<GuidedFilter> cv::ximgproc::createGuidedFilter | ( | InputArray | guide,
|  | int | radius,
|  | double | eps
| ) |  |

Python:
| retval | = | cv.ximgproc.createGuidedFilter( | guide, radius, eps | )

Factory method, create instance of GuidedFilter and produce initialization routines.

Parameters

  guide | guided image (or array of images) with up to 3 channels, if it have more then 3 channels then only first 3 channels will be used.
  radius | radius of Guided Filter.
  eps | regularization term of Guided Filter. \({eps}^2\) is similar to the sigma in the color space into bilateralFilter.

For more details about Guided Filter parameters, see the original article [76] .

## § createRightMatcher()

Ptr<StereoMatcher> cv::ximgproc::createRightMatcher | ( | Ptr< StereoMatcher > | matcher_left | ) |

Python:
| retval | = | cv.ximgproc.createRightMatcher( | matcher_left | )

Convenience method to set up the matcher for computing the right-view disparity map that is required in case of filtering with confidence.

Parameters

  matcher_left | main stereo matcher instance that will be used with the filter

## § dtFilter()

void cv::ximgproc::dtFilter | ( | InputArray | guide,
|  | InputArray | src,
|  | OutputArray | dst,
|  | double | sigmaSpatial,
|  | double | sigmaColor,
|  | int | mode = `DTF_NC`,
|  | int | numIters = `3`
| ) |  |

Python:
| dst | = | cv.ximgproc.dtFilter( | guide, src, sigmaSpatial, sigmaColor[, dst[, mode[, numIters]]] | )

Simple one-line Domain Transform filter call. If you have multiple images to filter with the same guided image then use DTFilter interface to avoid extra computations on initialization stage.

Parameters

  guide | guided image (also called as joint image) with unsigned 8-bit or floating-point 32-bit depth and up to 4 channels.
  src | filtering image with unsigned 8-bit or floating-point 32-bit depth and up to 4 channels.
  dst |
  sigmaSpatial | \({\sigma}_H\) parameter in the original article, it's similar to the sigma in the coordinate space into bilateralFilter.
  sigmaColor | \({\sigma}_r\) parameter in the original article, it's similar to the sigma in the color space into bilateralFilter.
  mode | one form three modes DTF_NC, DTF_RF and DTF_IC which corresponds to three modes for filtering 2D signals in the article.
  numIters | optional number of iterations used for filtering, 3 is quite enough.

See also
  bilateralFilter, guidedFilter, amFilter

## § fastGlobalSmootherFilter()

void cv::ximgproc::fastGlobalSmootherFilter | ( | InputArray | guide,
|  | InputArray | src,
|  | OutputArray | dst,
|  | double | lambda,
|  | double | sigma_color,
|  | double | lambda_attenuation = `0.25`,
|  | int | num_iter = `3`
| ) |  |

Python:
| dst | = | cv.ximgproc.fastGlobalSmootherFilter( | guide, src, lambda, sigma_color[, dst[, lambda_attenuation[, num_iter]]] | )

Simple one-line Fast Global Smoother filter call. If you have multiple images to filter with the same guide then use FastGlobalSmootherFilter interface to avoid extra computations.

Parameters

  guide | image serving as guide for filtering. It should have 8-bit depth and either 1 or 3 channels.
  src | source image for filtering with unsigned 8-bit or signed 16-bit or floating-point 32-bit depth and up to 4 channels.
  dst | destination image.
  lambda | parameter defining the amount of regularization
  sigma_color | parameter, that is similar to color space sigma in bilateralFilter.
  lambda_attenuation | internal parameter, defining how much lambda decreases after each iteration. Normally, it should be 0.25. Setting it to 1.0 may lead to streaking artifacts.
  num_iter | number of iterations used for filtering, 3 is usually enough.

## § getDisparityVis()

void cv::ximgproc::getDisparityVis | ( | InputArray | src,
|  | OutputArray | dst,
|  | double | scale = `1.0`
| ) |  |

Function for creating a disparity map visualization (clamped CV_8U image)

Parameters

  src | input disparity map (CV_16S depth)
  dst | output visualization
  scale | disparity map will be multiplied by this value for visualization

## § GradientDericheX()

void cv::ximgproc::GradientDericheX | ( | InputArray | _op,
|  | OutputArray | _dst,
|  | double | alphaDerive,
|  | double | alphaMean
| ) |  |

Applies X Deriche filter to an image.

For more details about this implementation, please see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.476.5736&rep=rep1&type=pdf

Parameters

  _op | Source 8-bit or 16bit image, 1-channel or 3-channel image.
  _dst | result CV_32FC image with same number of channel than _op.
  alphaDerive | double see paper
  alphaMean | double see paper

## § GradientDericheY()

void cv::ximgproc::GradientDericheY | ( | InputArray | _op,
|  | OutputArray | _dst,
|  | double | alphaDerive,
|  | double | alphaMean
| ) |  |

Applies Y Deriche filter to an image.

For more details about this implementation, please see http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.476.5736&rep=rep1&type=pdf

Parameters

  _op | Source 8-bit or 16bit image, 1-channel or 3-channel image.
  _dst | result CV_32FC image with same number of channel than _op.
  alphaDerive | double see paper
  alphaMean | double see paper

## § GradientPaillouX()

void cv::ximgproc::GradientPaillouX | ( | InputArray | op,
|  | OutputArray | _dst,
|  | double | alpha,
|  | double | omega
| ) |  |

## § GradientPaillouY()

void cv::ximgproc::GradientPaillouY | ( | InputArray | op,
|  | OutputArray | _dst,
|  | double | alpha,
|  | double | omega
| ) |  |

Applies Paillou filter to an image.

For more details about this implementation, please see [141]

Parameters

  op | Source CV_8U(S) or CV_16U(S), 1-channel or 3-channels image.
  _dst | result CV_32F image with same number of channel than op.
  omega | double see paper
  alpha | double see paper

See also
  GradientPaillouX, GradientPaillouY

## § guidedFilter()

void cv::ximgproc::guidedFilter | ( | InputArray | guide,
|  | InputArray | src,
|  | OutputArray | dst,
|  | int | radius,
|  | double | eps,
|  | int | dDepth = `-1`
| ) |  |

Python:
| dst | = | cv.ximgproc.guidedFilter( | guide, src, radius, eps[, dst[, dDepth]] | )

Simple one-line Guided Filter call.

If you have multiple images to filter with the same guided image then use GuidedFilter interface to avoid extra computations on initialization stage.

Parameters

  guide | guided image (or array of images) with up to 3 channels, if it have more then 3 channels then only first 3 channels will be used.
  src | filtering image with any numbers of channels.
  dst | output image.
  radius | radius of Guided Filter.
  eps | regularization term of Guided Filter. \({eps}^2\) is similar to the sigma in the color space into bilateralFilter.
  dDepth | optional depth of the output image.

See also
  bilateralFilter, dtFilter, amFilter

## § jointBilateralFilter()

void cv::ximgproc::jointBilateralFilter | ( | InputArray | joint,
|  | InputArray | src,
|  | OutputArray | dst,
|  | int | d,
|  | double | sigmaColor,
|  | double | sigmaSpace,
|  | int | borderType = `BORDER_DEFAULT`
| ) |  |

Python:
| dst | = | cv.ximgproc.jointBilateralFilter( | joint, src, d, sigmaColor, sigmaSpace[, dst[, borderType]] | )

Applies the joint bilateral filter to an image.

Parameters

  joint | Joint 8-bit or floating-point, 1-channel or 3-channel image.
  src | Source 8-bit or floating-point, 1-channel or 3-channel image with the same depth as joint image.
  dst | Destination image of the same size and type as src .
  d | Diameter of each pixel neighborhood that is used during filtering. If it is non-positive, it is computed from sigmaSpace .
  sigmaColor | Filter sigma in the color space. A larger value of the parameter means that farther colors within the pixel neighborhood (see sigmaSpace ) will be mixed together, resulting in larger areas of semi-equal color.
  sigmaSpace | Filter sigma in the coordinate space. A larger value of the parameter means that farther pixels will influence each other as long as their colors are close enough (see sigmaColor ). When d>0 , it specifies the neighborhood size regardless of sigmaSpace . Otherwise, d is proportional to sigmaSpace .
  borderType |

Note
  bilateralFilter and jointBilateralFilter use L1 norm to compute difference between colors.

See also
  bilateralFilter, amFilter

## § l0Smooth()

void cv::ximgproc::l0Smooth | ( | InputArray | src,
|  | OutputArray | dst,
|  | double | lambda = `0.02`,
|  | double | kappa = `2.0`
| ) |  |

Python:
| dst | = | cv.ximgproc.l0Smooth( | src[, dst[, lambda[, kappa]]] | )

Global image smoothing via L0 gradient minimization.

Parameters

  src | source image for filtering with unsigned 8-bit or signed 16-bit or floating-point depth.
  dst | destination image.
  lambda | parameter defining the smooth term weight.
  kappa | parameter defining the increasing factor of the weight of the gradient data term.

For more details about L0 Smoother, see the original paper [207].

## § readGT()

int cv::ximgproc::readGT | ( | String | src_path,
|  | OutputArray | dst
| ) |  |

Function for reading ground truth disparity maps. Supports basic Middlebury and MPI-Sintel formats. Note that the resulting disparity map is scaled by 16.

Parameters

  src_path | path to the image, containing ground-truth disparity map
  dst | output disparity map, CV_16S depth

Returns
  returns zero if successfully read the ground truth

## § rollingGuidanceFilter()

void cv::ximgproc::rollingGuidanceFilter | ( | InputArray | src,
|  | OutputArray | dst,
|  | int | d = `-1`,
|  | double | sigmaColor = `25`,
|  | double | sigmaSpace = `3`,
|  | int | numOfIter = `4`,
|  | int | borderType = `BORDER_DEFAULT`
| ) |  |

Python:
| dst | = | cv.ximgproc.rollingGuidanceFilter( | src[, dst[, d[, sigmaColor[, sigmaSpace[, numOfIter[, borderType]]]]]] | )

Applies the rolling guidance filter to an image.

For more details, please see [213]

Parameters

  src | Source 8-bit or floating-point, 1-channel or 3-channel image.
  dst | Destination image of the same size and type as src.
  d | Diameter of each pixel neighborhood that is used during filtering. If it is non-positive, it is computed from sigmaSpace .
  sigmaColor | Filter sigma in the color space. A larger value of the parameter means that farther colors within the pixel neighborhood (see sigmaSpace ) will be mixed together, resulting in larger areas of semi-equal color.
  sigmaSpace | Filter sigma in the coordinate space. A larger value of the parameter means that farther pixels will influence each other as long as their colors are close enough (see sigmaColor ). When d>0 , it specifies the neighborhood size regardless of sigmaSpace . Otherwise, d is proportional to sigmaSpace .
  numOfIter | Number of iterations of joint edge-preserving filtering applied on the source image.
  borderType |

Note
  rollingGuidanceFilter uses jointBilateralFilter as the edge-preserving filter.

See also
  jointBilateralFilter, bilateralFilter, amFilter