View Source Evision.QRCodeDetector (Evision v0.1.21)

Link to this section Summary

Types

t()

Type that represents an Evision.QRCodeDetector struct.

Functions

Decodes QR code in image once it's found by the detect() method.

Decodes QR code in image once it's found by the detect() method.

Decodes QR code on a curved surface in image once it's found by the detect() method.

Decodes QR code on a curved surface in image once it's found by the detect() method.

Decodes QR codes in image once it's found by the detect() method.

Decodes QR codes in image once it's found by the detect() method.

Detects QR code in image and returns the quadrangle containing the code.

Detects QR code in image and returns the quadrangle containing the code.

Both detects and decodes QR code

Both detects and decodes QR code

Both detects and decodes QR code on a curved surface

Both detects and decodes QR code on a curved surface

Both detects and decodes QR codes

Both detects and decodes QR codes

Detects QR codes in image and returns the vector of the quadrangles containing the codes.

Detects QR codes in image and returns the vector of the quadrangles containing the codes.

QRCodeDetector

sets the epsilon used during the horizontal scan of QR code stop marker detection.

sets the epsilon used during the vertical scan of QR code stop marker detection.

Link to this section Types

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

Type that represents an Evision.QRCodeDetector struct.

  • ref. reference()

    The underlying erlang resource variable.

Link to this section Functions

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decode(self, img, points)

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

Decodes QR code in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

  • points: Evision.Mat.

    Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: String

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Returns UTF8-encoded output string or empty string if the code cannot be decoded.

Python prototype (for reference only):

decode(img, points[, straight_qrcode]) -> retval, straight_qrcode
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decode(self, img, points, opts)

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

Decodes QR code in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

  • points: Evision.Mat.

    Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: String

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Returns UTF8-encoded output string or empty string if the code cannot be decoded.

Python prototype (for reference only):

decode(img, points[, straight_qrcode]) -> retval, straight_qrcode
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decodeCurved(self, img, points)

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

Decodes QR code on a curved surface in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

  • points: Evision.Mat.

    Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: String

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Returns UTF8-encoded output string or empty string if the code cannot be decoded.

Python prototype (for reference only):

decodeCurved(img, points[, straight_qrcode]) -> retval, straight_qrcode
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decodeCurved(self, img, points, opts)

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

Decodes QR code on a curved surface in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

  • points: Evision.Mat.

    Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: String

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Returns UTF8-encoded output string or empty string if the code cannot be decoded.

Python prototype (for reference only):

decodeCurved(img, points[, straight_qrcode]) -> retval, straight_qrcode
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decodeMulti(self, img, points)

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@spec decodeMulti(t(), Evision.Mat.maybe_mat_in(), Evision.Mat.maybe_mat_in()) ::
  {[binary()], [Evision.Mat.t()]} | false | {:error, String.t()}

Decodes QR codes in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR codes.

  • points: Evision.Mat.

    vector of Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: bool

  • decoded_info: [string].

    UTF8-encoded output vector of string or empty vector of string if the codes cannot be decoded.

  • straight_qrcode: [Evision.Mat].

    The optional output vector of images containing rectified and binarized QR codes

Python prototype (for reference only):

decodeMulti(img, points[, straight_qrcode]) -> retval, decoded_info, straight_qrcode
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decodeMulti(self, img, points, opts)

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

Decodes QR codes in image once it's found by the detect() method.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR codes.

  • points: Evision.Mat.

    vector of Quadrangle vertices found by detect() method (or some other algorithm).

Return
  • retval: bool

  • decoded_info: [string].

    UTF8-encoded output vector of string or empty vector of string if the codes cannot be decoded.

  • straight_qrcode: [Evision.Mat].

    The optional output vector of images containing rectified and binarized QR codes

Python prototype (for reference only):

decodeMulti(img, points[, straight_qrcode]) -> retval, decoded_info, straight_qrcode
@spec detect(t(), Evision.Mat.maybe_mat_in()) ::
  Evision.Mat.t() | false | {:error, String.t()}

Detects QR code in image and returns the quadrangle containing the code.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing (or not) QR code.

Return
  • retval: bool

  • points: Evision.Mat.

    Output vector of vertices of the minimum-area quadrangle containing the code.

Python prototype (for reference only):

detect(img[, points]) -> retval, points
@spec detect(t(), Evision.Mat.maybe_mat_in(), [{atom(), term()}, ...] | nil) ::
  Evision.Mat.t() | false | {:error, String.t()}

Detects QR code in image and returns the quadrangle containing the code.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing (or not) QR code.

Return
  • retval: bool

  • points: Evision.Mat.

    Output vector of vertices of the minimum-area quadrangle containing the code.

Python prototype (for reference only):

detect(img[, points]) -> retval, points
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detectAndDecode(self, img)

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

Both detects and decodes QR code

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

Return
  • retval: String

  • points: Evision.Mat.

    optional output array of vertices of the found QR code quadrangle. Will be empty if not found.

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Python prototype (for reference only):

detectAndDecode(img[, points[, straight_qrcode]]) -> retval, points, straight_qrcode
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detectAndDecode(self, img, opts)

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

Both detects and decodes QR code

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

Return
  • retval: String

  • points: Evision.Mat.

    optional output array of vertices of the found QR code quadrangle. Will be empty if not found.

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Python prototype (for reference only):

detectAndDecode(img[, points[, straight_qrcode]]) -> retval, points, straight_qrcode
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detectAndDecodeCurved(self, img)

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

Both detects and decodes QR code on a curved surface

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

Return
  • retval: String

  • points: Evision.Mat.

    optional output array of vertices of the found QR code quadrangle. Will be empty if not found.

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Python prototype (for reference only):

detectAndDecodeCurved(img[, points[, straight_qrcode]]) -> retval, points, straight_qrcode
Link to this function

detectAndDecodeCurved(self, img, opts)

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

Both detects and decodes QR code on a curved surface

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR code.

Return
  • retval: String

  • points: Evision.Mat.

    optional output array of vertices of the found QR code quadrangle. Will be empty if not found.

  • straight_qrcode: Evision.Mat.

    The optional output image containing rectified and binarized QR code

Python prototype (for reference only):

detectAndDecodeCurved(img[, points[, straight_qrcode]]) -> retval, points, straight_qrcode
Link to this function

detectAndDecodeMulti(self, img)

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@spec detectAndDecodeMulti(t(), Evision.Mat.maybe_mat_in()) ::
  {[binary()], Evision.Mat.t(), [Evision.Mat.t()]}
  | false
  | {:error, String.t()}

Both detects and decodes QR codes

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR codes.

Return
  • retval: bool

  • decoded_info: [string].

    UTF8-encoded output vector of string or empty vector of string if the codes cannot be decoded.

  • points: Evision.Mat.

    optional output vector of vertices of the found QR code quadrangles. Will be empty if not found.

  • straight_qrcode: [Evision.Mat].

    The optional output vector of images containing rectified and binarized QR codes

Python prototype (for reference only):

detectAndDecodeMulti(img[, points[, straight_qrcode]]) -> retval, decoded_info, points, straight_qrcode
Link to this function

detectAndDecodeMulti(self, img, opts)

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

Both detects and decodes QR codes

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing QR codes.

Return
  • retval: bool

  • decoded_info: [string].

    UTF8-encoded output vector of string or empty vector of string if the codes cannot be decoded.

  • points: Evision.Mat.

    optional output vector of vertices of the found QR code quadrangles. Will be empty if not found.

  • straight_qrcode: [Evision.Mat].

    The optional output vector of images containing rectified and binarized QR codes

Python prototype (for reference only):

detectAndDecodeMulti(img[, points[, straight_qrcode]]) -> retval, decoded_info, points, straight_qrcode
@spec detectMulti(t(), Evision.Mat.maybe_mat_in()) ::
  Evision.Mat.t() | false | {:error, String.t()}

Detects QR codes in image and returns the vector of the quadrangles containing the codes.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing (or not) QR codes.

Return
  • retval: bool

  • points: Evision.Mat.

    Output vector of vector of vertices of the minimum-area quadrangle containing the codes.

Python prototype (for reference only):

detectMulti(img[, points]) -> retval, points
Link to this function

detectMulti(self, img, opts)

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

Detects QR codes in image and returns the vector of the quadrangles containing the codes.

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

  • img: Evision.Mat.

    grayscale or color (BGR) image containing (or not) QR codes.

Return
  • retval: bool

  • points: Evision.Mat.

    Output vector of vector of vertices of the minimum-area quadrangle containing the codes.

Python prototype (for reference only):

detectMulti(img[, points]) -> retval, points
@spec qrCodeDetector() :: t() | {:error, String.t()}

QRCodeDetector

Return

Python prototype (for reference only):

QRCodeDetector() -> <QRCodeDetector object>
@spec setEpsX(t(), number()) :: :ok | {:error, String.t()}

sets the epsilon used during the horizontal scan of QR code stop marker detection.

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

  • epsX: double.

    Epsilon neighborhood, which allows you to determine the horizontal pattern of the scheme 1:1:3:1:1 according to QR code standard.

Python prototype (for reference only):

setEpsX(epsX) -> None
@spec setEpsY(t(), number()) :: :ok | {:error, String.t()}

sets the epsilon used during the vertical scan of QR code stop marker detection.

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

  • epsY: double.

    Epsilon neighborhood, which allows you to determine the vertical pattern of the scheme 1:1:3:1:1 according to QR code standard.

Python prototype (for reference only):

setEpsY(epsY) -> None