View Source Evision.Saliency.StaticSaliency (Evision v0.1.28)

Link to this section Summary

Types

t()

Type that represents an Saliency.StaticSaliency struct.

Functions

This function perform a binary map of given saliency map. This is obtained in this way

This function perform a binary map of given saliency map. This is obtained in this way

Link to this section Types

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

Type that represents an Saliency.StaticSaliency struct.

  • ref. reference()

    The underlying erlang resource variable.

Link to this section Functions

Link to this function

computeBinaryMap(self, saliencyMap)

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

This function perform a binary map of given saliency map. This is obtained in this way:

Positional Arguments
  • self: Evision.Saliency.StaticSaliency.t()

  • saliencyMap: Evision.Mat.t().

    the saliency map obtained through one of the specialized algorithms

Return
  • retval: bool

  • binaryMap: Evision.Mat.t().

    the binary map

In a first step, to improve the definition of interest areas and facilitate identification of targets, a segmentation by clustering is performed, using K-means algorithm. Then, to gain a binary representation of clustered saliency map, since values of the map can vary according to the characteristics of frame under analysis, it is not convenient to use a fixed threshold. So, Otsu's algorithm* is used, which assumes that the image to be thresholded contains two classes of pixels or bi-modal histograms (e.g. foreground and back-ground pixels); later on, the algorithm calculates the optimal threshold separating those two classes, so that their intra-class variance is minimal.

Python prototype (for reference only):

computeBinaryMap(_saliencyMap[, _binaryMap]) -> retval, _binaryMap
Link to this function

computeBinaryMap(self, saliencyMap, opts)

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

This function perform a binary map of given saliency map. This is obtained in this way:

Positional Arguments
  • self: Evision.Saliency.StaticSaliency.t()

  • saliencyMap: Evision.Mat.t().

    the saliency map obtained through one of the specialized algorithms

Return
  • retval: bool

  • binaryMap: Evision.Mat.t().

    the binary map

In a first step, to improve the definition of interest areas and facilitate identification of targets, a segmentation by clustering is performed, using K-means algorithm. Then, to gain a binary representation of clustered saliency map, since values of the map can vary according to the characteristics of frame under analysis, it is not convenient to use a fixed threshold. So, Otsu's algorithm* is used, which assumes that the image to be thresholded contains two classes of pixels or bi-modal histograms (e.g. foreground and back-ground pixels); later on, the algorithm calculates the optimal threshold separating those two classes, so that their intra-class variance is minimal.

Python prototype (for reference only):

computeBinaryMap(_saliencyMap[, _binaryMap]) -> retval, _binaryMap