View Source Evision.SparseOpticalFlow (Evision v0.1.21)

Link to this section Summary

Types

t()

Type that represents an Evision.SparseOpticalFlow struct.

Functions

Calculates a sparse optical flow.

Calculates a sparse optical flow.

Clears the algorithm state

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

getDefaultName

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.SparseOpticalFlow{ref: reference()}

Type that represents an Evision.SparseOpticalFlow struct.

  • ref. reference()

    The underlying erlang resource variable.

Link to this section Functions

Link to this function

calc(self, prevImg, nextImg, prevPts, nextPts)

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Calculates a sparse optical flow.

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

  • prevImg: Evision.Mat.

    First input image.

  • nextImg: Evision.Mat.

    Second input image of the same size and the same type as prevImg.

  • prevPts: Evision.Mat.

    Vector of 2D points for which the flow needs to be found.

Return
  • nextPts: Evision.Mat.

    Output vector of 2D points containing the calculated new positions of input features in the second image.

  • status: Evision.Mat.

    Output status vector. Each element of the vector is set to 1 if the flow for the corresponding features has been found. Otherwise, it is set to 0.

  • err: Evision.Mat.

    Optional output vector that contains error response for each point (inverse confidence).

Python prototype (for reference only):

calc(prevImg, nextImg, prevPts, nextPts[, status[, err]]) -> nextPts, status, err
Link to this function

calc(self, prevImg, nextImg, prevPts, nextPts, opts)

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Calculates a sparse optical flow.

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

  • prevImg: Evision.Mat.

    First input image.

  • nextImg: Evision.Mat.

    Second input image of the same size and the same type as prevImg.

  • prevPts: Evision.Mat.

    Vector of 2D points for which the flow needs to be found.

Return
  • nextPts: Evision.Mat.

    Output vector of 2D points containing the calculated new positions of input features in the second image.

  • status: Evision.Mat.

    Output status vector. Each element of the vector is set to 1 if the flow for the corresponding features has been found. Otherwise, it is set to 0.

  • err: Evision.Mat.

    Optional output vector that contains error response for each point (inverse confidence).

Python prototype (for reference only):

calc(prevImg, nextImg, prevPts, nextPts[, status[, err]]) -> nextPts, status, err
@spec clear(t()) :: :ok | {:error, String.t()}

Clears the algorithm state

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

Python prototype (for reference only):

clear() -> None
@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.SparseOpticalFlow.t()
Return
  • retval: bool

Python prototype (for reference only):

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

getDefaultName

Positional Arguments
  • self: Evision.SparseOpticalFlow.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 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.SparseOpticalFlow.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
@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