View Source Evision.StereoSGBM (Evision v0.2.9)

Summary

Types

t()

Type that represents an 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

getDisp12MaxDiff

getMinDisparity

getNumDisparities

getPreFilterCap

getSpeckleRange

getSpeckleWindowSize

getUniquenessRatio

Reads algorithm parameters from a file storage

Stores algorithm parameters in a file storage

Enumerator

Types

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

Type that represents an StereoSGBM struct.

  • ref. reference()

    The underlying erlang resource variable.

Functions

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

Clears the algorithm state

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

Python prototype (for reference only):

clear() -> None
@spec compute(Keyword.t()) :: any() | {:error, String.t()}
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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.t().

    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.t().

    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: integer().

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

  • numDisparities: integer().

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

  • blockSize: integer().

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

  • p1: integer().

    The first parameter controlling the disparity smoothness. See below.

  • p2: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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
  • retval: Evision.StereoSGBM.t()

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(Keyword.t()) :: any() | {:error, String.t()}
@spec create(
  [
    blockSize: term(),
    disp12MaxDiff: term(),
    minDisparity: term(),
    mode: term(),
    numDisparities: term(),
    p1: term(),
    p2: term(),
    preFilterCap: term(),
    speckleRange: term(),
    speckleWindowSize: term(),
    uniquenessRatio: term()
  ]
  | nil
) :: t() | {:error, String.t()}

Creates StereoSGBM object

Keyword Arguments
  • minDisparity: integer().

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

  • numDisparities: integer().

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

  • blockSize: integer().

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

  • p1: integer().

    The first parameter controlling the disparity smoothness. See below.

  • p2: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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: integer().

    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
  • retval: Evision.StereoSGBM.t()

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(Keyword.t()) :: any() | {:error, String.t()}
@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
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getBlockSize(named_args)

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@spec getBlockSize(Keyword.t()) :: any() | {:error, String.t()}
@spec getBlockSize(t()) :: integer() | {:error, String.t()}

getBlockSize

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

Python prototype (for reference only):

getBlockSize() -> retval
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getDefaultName(named_args)

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@spec getDefaultName(Keyword.t()) :: any() | {:error, String.t()}
@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
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getDisp12MaxDiff(named_args)

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@spec getDisp12MaxDiff(Keyword.t()) :: any() | {:error, String.t()}
@spec getDisp12MaxDiff(t()) :: integer() | {:error, String.t()}

getDisp12MaxDiff

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

Python prototype (for reference only):

getDisp12MaxDiff() -> retval
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getMinDisparity(named_args)

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@spec getMinDisparity(Keyword.t()) :: any() | {:error, String.t()}
@spec getMinDisparity(t()) :: integer() | {:error, String.t()}

getMinDisparity

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

Python prototype (for reference only):

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

getMode

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

Python prototype (for reference only):

getMode() -> retval
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getNumDisparities(named_args)

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@spec getNumDisparities(Keyword.t()) :: any() | {:error, String.t()}
@spec getNumDisparities(t()) :: integer() | {:error, String.t()}

getNumDisparities

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

Python prototype (for reference only):

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

getP1

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

Python prototype (for reference only):

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

getP2

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

Python prototype (for reference only):

getP2() -> retval
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getPreFilterCap(named_args)

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@spec getPreFilterCap(Keyword.t()) :: any() | {:error, String.t()}
@spec getPreFilterCap(t()) :: integer() | {:error, String.t()}

getPreFilterCap

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

Python prototype (for reference only):

getPreFilterCap() -> retval
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getSpeckleRange(named_args)

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@spec getSpeckleRange(Keyword.t()) :: any() | {:error, String.t()}
@spec getSpeckleRange(t()) :: integer() | {:error, String.t()}

getSpeckleRange

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

Python prototype (for reference only):

getSpeckleRange() -> retval
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getSpeckleWindowSize(named_args)

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

getSpeckleWindowSize

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

Python prototype (for reference only):

getSpeckleWindowSize() -> retval
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getUniquenessRatio(named_args)

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

getUniquenessRatio

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

Python prototype (for reference only):

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

Reads algorithm parameters from a file storage

Positional Arguments

Python prototype (for reference only):

read(fn) -> None
@spec save(Keyword.t()) :: any() | {:error, String.t()}
@spec save(t(), binary()) :: t() | {: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(named_args)

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@spec setBlockSize(Keyword.t()) :: any() | {:error, String.t()}
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setBlockSize(self, blockSize)

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

setBlockSize

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

Python prototype (for reference only):

setBlockSize(blockSize) -> None
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setDisp12MaxDiff(named_args)

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@spec setDisp12MaxDiff(Keyword.t()) :: any() | {:error, String.t()}
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setDisp12MaxDiff(self, disp12MaxDiff)

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

setDisp12MaxDiff

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

Python prototype (for reference only):

setDisp12MaxDiff(disp12MaxDiff) -> None
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setMinDisparity(named_args)

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@spec setMinDisparity(Keyword.t()) :: any() | {:error, String.t()}
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setMinDisparity(self, minDisparity)

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

setMinDisparity

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

Python prototype (for reference only):

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

setMode

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

Python prototype (for reference only):

setMode(mode) -> None
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setNumDisparities(named_args)

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@spec setNumDisparities(Keyword.t()) :: any() | {:error, String.t()}
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setNumDisparities(self, numDisparities)

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

setNumDisparities

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

Python prototype (for reference only):

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

setP1

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

Python prototype (for reference only):

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

setP2

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

Python prototype (for reference only):

setP2(P2) -> None
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setPreFilterCap(named_args)

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@spec setPreFilterCap(Keyword.t()) :: any() | {:error, String.t()}
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setPreFilterCap(self, preFilterCap)

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

setPreFilterCap

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

Python prototype (for reference only):

setPreFilterCap(preFilterCap) -> None
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setSpeckleRange(named_args)

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@spec setSpeckleRange(Keyword.t()) :: any() | {:error, String.t()}
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setSpeckleRange(self, speckleRange)

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

setSpeckleRange

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

Python prototype (for reference only):

setSpeckleRange(speckleRange) -> None
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setSpeckleWindowSize(named_args)

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@spec setSpeckleWindowSize(Keyword.t()) :: any() | {:error, String.t()}
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setSpeckleWindowSize(self, speckleWindowSize)

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

setSpeckleWindowSize

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

Python prototype (for reference only):

setSpeckleWindowSize(speckleWindowSize) -> None
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setUniquenessRatio(named_args)

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@spec setUniquenessRatio(Keyword.t()) :: any() | {:error, String.t()}
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setUniquenessRatio(self, uniquenessRatio)

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

setUniquenessRatio

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

Python prototype (for reference only):

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

Stores algorithm parameters in a file storage

Positional Arguments

Python prototype (for reference only):

write(fs) -> None
@spec write(t(), Evision.FileStorage.t(), binary()) :: t() | {:error, String.t()}

write

Positional Arguments

Has overloading in C++

Python prototype (for reference only):

write(fs, name) -> None