OpenCV: Stereo Correspondence

| OpenCV 3.4.2 Open Source Computer Vision

Classes | Functions
Stereo Correspondence
Core functionality » OpenGL interoperability » CUDA-accelerated Computer Vision

## Classes
class | cv::cuda::DisparityBilateralFilter
| Class refining a disparity map using joint bilateral filtering. : More...
class | cv::cuda::StereoBeliefPropagation
| Class computing stereo correspondence using the belief propagation algorithm. : More...
class | cv::cuda::StereoBM
| Class computing stereo correspondence (disparity map) using the block matching algorithm. : More...
class | cv::cuda::StereoConstantSpaceBP
| Class computing stereo correspondence using the constant space belief propagation algorithm. : More...

## Functions
Ptr< cuda::DisparityBilateralFilter > | cv::cuda::createDisparityBilateralFilter (int ndisp=64, int radius=3, int iters=1)
| Creates DisparityBilateralFilter object. More...
Ptr< cuda::StereoBeliefPropagation > | cv::cuda::createStereoBeliefPropagation (int ndisp=64, int iters=5, int levels=5, int msg_type=CV_32F)
| Creates StereoBeliefPropagation object. More...
Ptr< cuda::StereoBM > | cv::cuda::createStereoBM (int numDisparities=64, int blockSize=19)
| Creates StereoBM object. More...
Ptr< cuda::StereoConstantSpaceBP > | cv::cuda::createStereoConstantSpaceBP (int ndisp=128, int iters=8, int levels=4, int nr_plane=4, int msg_type=CV_32F)
| Creates StereoConstantSpaceBP object. More...
void | cv::cuda::drawColorDisp (InputArray src_disp, OutputArray dst_disp, int ndisp, Stream &stream=Stream::Null())
| Colors a disparity image. More...
void | cv::cuda::reprojectImageTo3D (InputArray disp, OutputArray xyzw, InputArray Q, int dst_cn=4, Stream &stream=Stream::Null())
| Reprojects a disparity image to 3D space. More...

## Detailed Description

## Function Documentation

## ◆ createDisparityBilateralFilter()

Ptr<cuda::DisparityBilateralFilter> cv::cuda::createDisparityBilateralFilter | ( | int | ndisp = `64`,
|  | int | radius = `3`,
|  | int | iters = `1`
| ) |  |

Creates DisparityBilateralFilter object.

Parameters

  ndisp | Number of disparities.
  radius | Filter radius.
  iters | Number of iterations.

## ◆ createStereoBeliefPropagation()

Ptr<cuda::StereoBeliefPropagation> cv::cuda::createStereoBeliefPropagation | ( | int | ndisp = `64`,
|  | int | iters = `5`,
|  | int | levels = `5`,
|  | int | msg_type = `CV_32F`
| ) |  |

Creates StereoBeliefPropagation object.

Parameters

  ndisp | Number of disparities.
  iters | Number of BP iterations on each level.
  levels | Number of levels.
  msg_type | Type for messages. CV_16SC1 and CV_32FC1 types are supported.

## ◆ createStereoBM()

Ptr<cuda::StereoBM> cv::cuda::createStereoBM | ( | int | numDisparities = `64`,
|  | int | blockSize = `19`
| ) |  |

Creates StereoBM object.

Parameters

  numDisparities | the disparity search range. For each pixel algorithm will find the best disparity from 0 (default minimum disparity) to numDisparities. The search range can then be shifted by changing the minimum disparity.
  blockSize | the linear size of the blocks compared by the algorithm. The size should be odd (as the block is centered at the current pixel). Larger block size implies smoother, though less accurate disparity map. Smaller block size gives more detailed disparity map, but there is higher chance for algorithm to find a wrong correspondence.

## ◆ createStereoConstantSpaceBP()

Ptr<cuda::StereoConstantSpaceBP> cv::cuda::createStereoConstantSpaceBP | ( | int | ndisp = `128`,
|  | int | iters = `8`,
|  | int | levels = `4`,
|  | int | nr_plane = `4`,
|  | int | msg_type = `CV_32F`
| ) |  |

Creates StereoConstantSpaceBP object.

Parameters

  ndisp | Number of disparities.
  iters | Number of BP iterations on each level.
  levels | Number of levels.
  nr_plane | Number of disparity levels on the first level.
  msg_type | Type for messages. CV_16SC1 and CV_32FC1 types are supported.

## ◆ drawColorDisp()

void cv::cuda::drawColorDisp | ( | InputArray | src_disp,
|  | OutputArray | dst_disp,
|  | int | ndisp,
|  | Stream & | stream = `Stream::Null()`
| ) |  |

Colors a disparity image.

Parameters

  src_disp | Input single-channel 8-bit unsigned, 16-bit signed, 32-bit signed or 32-bit floating-point disparity image. If 16-bit signed format is used, the values are assumed to have no fractional bits.
  dst_disp | Output disparity image. It has the same size as src_disp. The type is CV_8UC4 in BGRA format (alpha = 255).
  ndisp | Number of disparities.
  stream | Stream for the asynchronous version.

This function draws a colored disparity map by converting disparity values from [0..ndisp) interval first to HSV color space (where different disparity values correspond to different hues) and then converting the pixels to RGB for visualization.

## ◆ reprojectImageTo3D()

void cv::cuda::reprojectImageTo3D | ( | InputArray | disp,
|  | OutputArray | xyzw,
|  | InputArray | Q,
|  | int | dst_cn = `4`,
|  | Stream & | stream = `Stream::Null()`
| ) |  |

Reprojects a disparity image to 3D space.

Parameters

  disp | Input single-channel 8-bit unsigned, 16-bit signed, 32-bit signed or 32-bit floating-point disparity image. If 16-bit signed format is used, the values are assumed to have no fractional bits.
  xyzw | Output 3- or 4-channel floating-point image of the same size as disp . Each element of xyzw(x,y) contains 3D coordinates (x,y,z) or (x,y,z,1) of the point (x,y) , computed from the disparity map.
  Q | \(4 \times 4\) perspective transformation matrix that can be obtained via stereoRectify .
  dst_cn | The number of channels for output image. Can be 3 or 4.
  stream | Stream for the asynchronous version.

See also
  reprojectImageTo3D