View Source Evision.StereoSGBM (Evision v0.1.21)

Link to this section Summary

Types

t()

Type that represents an Evision.StereoSGBM struct.

Functions

Clears the algorithm state

Computes disparity map for the specified stereo pair

Computes disparity map for the specified stereo pair

Creates StereoSGBM object

Creates StereoSGBM object

Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read

getBlockSize

getDefaultName

getDisp12MaxDiff

getMinDisparity

getMode

getNumDisparities

getP1

getP2

getPreFilterCap

getSpeckleRange

getSpeckleWindowSize

getUniquenessRatio

Reads algorithm parameters from a file storage

simplified API for language bindings

simplified API for language bindings

Link to this section Types

@type t() :: %Evision.StereoSGBM{ref: reference()}

Type that represents an Evision.StereoSGBM struct.

  • ref. reference()

    The underlying erlang resource variable.

Link to this section Functions

@spec clear(t()) :: :ok | {:error, String.t()}

Clears the algorithm state

Positional Arguments
  • self: Evision.StereoSGBM.t()

Python prototype (for reference only):

clear() -> None
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compute(self, left, right)

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@spec compute(t(), Evision.Mat.maybe_mat_in(), Evision.Mat.maybe_mat_in()) ::
  Evision.Mat.t() | {:error, String.t()}

Computes disparity map for the specified stereo pair

Positional Arguments
  • self: Evision.StereoSGBM.t()

  • left: Evision.Mat.

    Left 8-bit single-channel image.

  • right: Evision.Mat.

    Right image of the same size and the same type as the left one.

Return
  • disparity: Evision.Mat.

    Output disparity map. It has the same size as the input images. Some algorithms, like StereoBM or StereoSGBM compute 16-bit fixed-point disparity map (where each disparity value has 4 fractional bits), whereas other algorithms output 32-bit floating-point disparity map.

Python prototype (for reference only):

compute(left, right[, disparity]) -> disparity
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compute(self, left, right, opts)

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@spec compute(
  t(),
  Evision.Mat.maybe_mat_in(),
  Evision.Mat.maybe_mat_in(),
  [{atom(), term()}, ...] | nil
) :: Evision.Mat.t() | {:error, String.t()}

Computes disparity map for the specified stereo pair

Positional Arguments
  • self: Evision.StereoSGBM.t()

  • left: Evision.Mat.

    Left 8-bit single-channel image.

  • right: Evision.Mat.

    Right image of the same size and the same type as the left one.

Return
  • disparity: Evision.Mat.

    Output disparity map. It has the same size as the input images. Some algorithms, like StereoBM or StereoSGBM compute 16-bit fixed-point disparity map (where each disparity value has 4 fractional bits), whereas other algorithms output 32-bit floating-point disparity map.

Python prototype (for reference only):

compute(left, right[, disparity]) -> disparity
@spec create() :: t() | {:error, String.t()}

Creates StereoSGBM object

Keyword Arguments
  • minDisparity: int.

    Minimum possible disparity value. Normally, it is zero but sometimes rectification algorithms can shift images, so this parameter needs to be adjusted accordingly.

  • numDisparities: int.

    Maximum disparity minus minimum disparity. The value is always greater than zero. In the current implementation, this parameter must be divisible by 16.

  • blockSize: int.

    Matched block size. It must be an odd number >=1 . Normally, it should be somewhere in the 3..11 range.

  • p1: int.

    The first parameter controlling the disparity smoothness. See below.

  • p2: int.

    The second parameter controlling the disparity smoothness. The larger the values are, the smoother the disparity is. P1 is the penalty on the disparity change by plus or minus 1 between neighbor pixels. P2 is the penalty on the disparity change by more than 1 between neighbor pixels. The algorithm requires P2 > P1 . See stereo_match.cpp sample where some reasonably good P1 and P2 values are shown (like 8*number_of_image_channels*blockSize*blockSize and 32*number_of_image_channels*blockSize*blockSize , respectively).

  • disp12MaxDiff: int.

    Maximum allowed difference (in integer pixel units) in the left-right disparity check. Set it to a non-positive value to disable the check.

  • preFilterCap: int.

    Truncation value for the prefiltered image pixels. The algorithm first computes x-derivative at each pixel and clips its value by [-preFilterCap, preFilterCap] interval. The result values are passed to the Birchfield-Tomasi pixel cost function.

  • uniquenessRatio: int.

    Margin in percentage by which the best (minimum) computed cost function value should "win" the second best value to consider the found match correct. Normally, a value within the 5-15 range is good enough.

  • speckleWindowSize: int.

    Maximum size of smooth disparity regions to consider their noise speckles and invalidate. Set it to 0 to disable speckle filtering. Otherwise, set it somewhere in the 50-200 range.

  • speckleRange: int.

    Maximum disparity variation within each connected component. If you do speckle filtering, set the parameter to a positive value, it will be implicitly multiplied by 16. Normally, 1 or 2 is good enough.

  • mode: int.

    Set it to StereoSGBM::MODE_HH to run the full-scale two-pass dynamic programming algorithm. It will consume O(W*H*numDisparities) bytes, which is large for 640x480 stereo and huge for HD-size pictures. By default, it is set to false .

Return

The first constructor initializes StereoSGBM with all the default parameters. So, you only have to set StereoSGBM::numDisparities at minimum. The second constructor enables you to set each parameter to a custom value.

Python prototype (for reference only):

create([, minDisparity[, numDisparities[, blockSize[, P1[, P2[, disp12MaxDiff[, preFilterCap[, uniquenessRatio[, speckleWindowSize[, speckleRange[, mode]]]]]]]]]]]) -> retval
@spec create([{atom(), term()}, ...] | nil) :: t() | {:error, String.t()}

Creates StereoSGBM object

Keyword Arguments
  • minDisparity: int.

    Minimum possible disparity value. Normally, it is zero but sometimes rectification algorithms can shift images, so this parameter needs to be adjusted accordingly.

  • numDisparities: int.

    Maximum disparity minus minimum disparity. The value is always greater than zero. In the current implementation, this parameter must be divisible by 16.

  • blockSize: int.

    Matched block size. It must be an odd number >=1 . Normally, it should be somewhere in the 3..11 range.

  • p1: int.

    The first parameter controlling the disparity smoothness. See below.

  • p2: int.

    The second parameter controlling the disparity smoothness. The larger the values are, the smoother the disparity is. P1 is the penalty on the disparity change by plus or minus 1 between neighbor pixels. P2 is the penalty on the disparity change by more than 1 between neighbor pixels. The algorithm requires P2 > P1 . See stereo_match.cpp sample where some reasonably good P1 and P2 values are shown (like 8*number_of_image_channels*blockSize*blockSize and 32*number_of_image_channels*blockSize*blockSize , respectively).

  • disp12MaxDiff: int.

    Maximum allowed difference (in integer pixel units) in the left-right disparity check. Set it to a non-positive value to disable the check.

  • preFilterCap: int.

    Truncation value for the prefiltered image pixels. The algorithm first computes x-derivative at each pixel and clips its value by [-preFilterCap, preFilterCap] interval. The result values are passed to the Birchfield-Tomasi pixel cost function.

  • uniquenessRatio: int.

    Margin in percentage by which the best (minimum) computed cost function value should "win" the second best value to consider the found match correct. Normally, a value within the 5-15 range is good enough.

  • speckleWindowSize: int.

    Maximum size of smooth disparity regions to consider their noise speckles and invalidate. Set it to 0 to disable speckle filtering. Otherwise, set it somewhere in the 50-200 range.

  • speckleRange: int.

    Maximum disparity variation within each connected component. If you do speckle filtering, set the parameter to a positive value, it will be implicitly multiplied by 16. Normally, 1 or 2 is good enough.

  • mode: int.

    Set it to StereoSGBM::MODE_HH to run the full-scale two-pass dynamic programming algorithm. It will consume O(W*H*numDisparities) bytes, which is large for 640x480 stereo and huge for HD-size pictures. By default, it is set to false .

Return

The first constructor initializes StereoSGBM with all the default parameters. So, you only have to set StereoSGBM::numDisparities at minimum. The second constructor enables you to set each parameter to a custom value.

Python prototype (for reference only):

create([, minDisparity[, numDisparities[, blockSize[, P1[, P2[, disp12MaxDiff[, preFilterCap[, uniquenessRatio[, speckleWindowSize[, speckleRange[, mode]]]]]]]]]]]) -> retval
@spec empty(t()) :: boolean() | {:error, String.t()}

Returns true if the Algorithm is empty (e.g. in the very beginning or after unsuccessful read

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: bool

Python prototype (for reference only):

empty() -> retval
@spec getBlockSize(t()) :: integer() | {:error, String.t()}

getBlockSize

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getBlockSize() -> retval
@spec getDefaultName(t()) :: binary() | {:error, String.t()}

getDefaultName

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return

Returns the algorithm string identifier. This string is used as top level xml/yml node tag when the object is saved to a file or string.

Python prototype (for reference only):

getDefaultName() -> retval
@spec getDisp12MaxDiff(t()) :: integer() | {:error, String.t()}

getDisp12MaxDiff

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getDisp12MaxDiff() -> retval
@spec getMinDisparity(t()) :: integer() | {:error, String.t()}

getMinDisparity

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getMinDisparity() -> retval
@spec getMode(t()) :: integer() | {:error, String.t()}

getMode

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getMode() -> retval
@spec getNumDisparities(t()) :: integer() | {:error, String.t()}

getNumDisparities

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getNumDisparities() -> retval
@spec getP1(t()) :: integer() | {:error, String.t()}

getP1

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getP1() -> retval
@spec getP2(t()) :: integer() | {:error, String.t()}

getP2

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getP2() -> retval
@spec getPreFilterCap(t()) :: integer() | {:error, String.t()}

getPreFilterCap

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getPreFilterCap() -> retval
@spec getSpeckleRange(t()) :: integer() | {:error, String.t()}

getSpeckleRange

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getSpeckleRange() -> retval
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getSpeckleWindowSize(self)

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@spec getSpeckleWindowSize(t()) :: integer() | {:error, String.t()}

getSpeckleWindowSize

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getSpeckleWindowSize() -> retval
Link to this function

getUniquenessRatio(self)

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@spec getUniquenessRatio(t()) :: integer() | {:error, String.t()}

getUniquenessRatio

Positional Arguments
  • self: Evision.StereoSGBM.t()
Return
  • retval: int

Python prototype (for reference only):

getUniquenessRatio() -> retval
@spec read(t(), Evision.FileNode.t()) :: :ok | {:error, String.t()}

Reads algorithm parameters from a file storage

Positional Arguments

Python prototype (for reference only):

read(fn_) -> None
@spec save(t(), binary()) :: :ok | {:error, String.t()}

save

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • filename: String

Saves the algorithm to a file. In order to make this method work, the derived class must implement Algorithm::write(FileStorage& fs).

Python prototype (for reference only):

save(filename) -> None
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setBlockSize(self, blockSize)

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@spec setBlockSize(t(), integer()) :: :ok | {:error, String.t()}

setBlockSize

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • blockSize: int

Python prototype (for reference only):

setBlockSize(blockSize) -> None
Link to this function

setDisp12MaxDiff(self, disp12MaxDiff)

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@spec setDisp12MaxDiff(t(), integer()) :: :ok | {:error, String.t()}

setDisp12MaxDiff

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • disp12MaxDiff: int

Python prototype (for reference only):

setDisp12MaxDiff(disp12MaxDiff) -> None
Link to this function

setMinDisparity(self, minDisparity)

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@spec setMinDisparity(t(), integer()) :: :ok | {:error, String.t()}

setMinDisparity

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • minDisparity: int

Python prototype (for reference only):

setMinDisparity(minDisparity) -> None
@spec setMode(t(), integer()) :: :ok | {:error, String.t()}

setMode

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • mode: int

Python prototype (for reference only):

setMode(mode) -> None
Link to this function

setNumDisparities(self, numDisparities)

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@spec setNumDisparities(t(), integer()) :: :ok | {:error, String.t()}

setNumDisparities

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • numDisparities: int

Python prototype (for reference only):

setNumDisparities(numDisparities) -> None
@spec setP1(t(), integer()) :: :ok | {:error, String.t()}

setP1

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • p1: int

Python prototype (for reference only):

setP1(P1) -> None
@spec setP2(t(), integer()) :: :ok | {:error, String.t()}

setP2

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • p2: int

Python prototype (for reference only):

setP2(P2) -> None
Link to this function

setPreFilterCap(self, preFilterCap)

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@spec setPreFilterCap(t(), integer()) :: :ok | {:error, String.t()}

setPreFilterCap

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • preFilterCap: int

Python prototype (for reference only):

setPreFilterCap(preFilterCap) -> None
Link to this function

setSpeckleRange(self, speckleRange)

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@spec setSpeckleRange(t(), integer()) :: :ok | {:error, String.t()}

setSpeckleRange

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • speckleRange: int

Python prototype (for reference only):

setSpeckleRange(speckleRange) -> None
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setSpeckleWindowSize(self, speckleWindowSize)

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@spec setSpeckleWindowSize(t(), integer()) :: :ok | {:error, String.t()}

setSpeckleWindowSize

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • speckleWindowSize: int

Python prototype (for reference only):

setSpeckleWindowSize(speckleWindowSize) -> None
Link to this function

setUniquenessRatio(self, uniquenessRatio)

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@spec setUniquenessRatio(t(), integer()) :: :ok | {:error, String.t()}

setUniquenessRatio

Positional Arguments
  • self: Evision.StereoSGBM.t()
  • uniquenessRatio: int

Python prototype (for reference only):

setUniquenessRatio(uniquenessRatio) -> None
@spec write(t(), Evision.FileStorage.t()) :: :ok | {:error, String.t()}

simplified API for language bindings

Positional Arguments
Keyword Arguments

Has overloading in C++

Python prototype (for reference only):

write(fs[, name]) -> None
@spec write(t(), Evision.FileStorage.t(), [{atom(), term()}, ...] | nil) ::
  :ok | {:error, String.t()}

simplified API for language bindings

Positional Arguments
Keyword Arguments

Has overloading in C++

Python prototype (for reference only):

write(fs[, name]) -> None