Class cv::structured_light::GrayCodePattern#

Class implementing the Gray-code pattern, based on [139]. View details

Collaboration diagram for cv::structured_light::GrayCodePattern:

Public Member Functions#

Public Member Functions inherited from cv::structured_light::StructuredLightPattern
Public Member Functions inherited from cv::Algorithm

Return

Name

Description

Algorithm()

~Algorithm()

void

clear()

Clears the algorithm state.

bool

empty()

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

String

getDefaultName()

void

read(const FileNode & fn)

Reads algorithm parameters from a file storage.

void

save(const String & filename)

void

write(
    const Ptr< FileStorage > & fs,
    const String & name = String() )

void

write(FileStorage & fs)

Stores algorithm parameters in a file storage.

void

write(
    FileStorage & fs,
    const String & name )

Static Public Member Functions#

Static Public Member Functions inherited from cv::Algorithm

Return

Name

Description

static Ptr< _Tp >

load(
    const String & filename,
    const String & objname = String() )

Loads algorithm from the file.

static Ptr< _Tp >

loadFromString(
    const String & strModel,
    const String & objname = String() )

Loads algorithm from a String.

static Ptr< _Tp >

read(const FileNode & fn)

Reads algorithm from the file node.

Additional Inherited Members#

Protected Member Functions inherited from cv::Algorithm

Return

Name

Description

void

writeFormat(FileStorage & fs)

Detailed Description#

Class implementing the Gray-code pattern, based on UNDERWORLD.

The generation of the pattern images is performed with Gray encoding using the traditional white and black colors.

The information about the two image axes x, y is encoded separately into two different pattern sequences. A projector P with resolution (P_res_x, P_res_y) will result in Ncols = log 2 (P_res_x) encoded pattern images representing the columns, and in Nrows = log 2 (P_res_y) encoded pattern images representing the rows. For example a projector with resolution 1024x768 will result in Ncols = 10 and Nrows = 10.

However, the generated pattern sequence consists of both regular color and color-inverted images: inverted pattern images are images with the same structure as the original but with inverted colors. This provides an effective method for easily determining the intensity value of each pixel when it is lit (highest value) and when it is not lit (lowest value). So for a a projector with resolution 1024x768, the number of pattern images will be Ncols * 2 + Nrows * 2 = 40.

Member Function Documentation#

create()#

static Ptr< GrayCodePattern > cv::structured_light::GrayCodePattern::create(const GrayCodePattern::Params & parameters = GrayCodePattern::Params())

Constructor.

Parameters

create()#

static Ptr< GrayCodePattern > cv::structured_light::GrayCodePattern::create(
int width,
int height )

getImagesForShadowMasks()#

void cv::structured_light::GrayCodePattern::getImagesForShadowMasks(
InputOutputArray blackImage,
InputOutputArray whiteImage )

Generates the all-black and all-white images needed for shadowMasks computation.

To identify shadow regions, the regions of two images where the pixels are not lit by projector’s light and thus where there is not coded information, the 3DUNDERWORLD algorithm computes a shadow mask for the two cameras views, starting from a white and a black images captured by each camera. This method generates these two additional images to project.

Parameters

  • blackImage — The generated all-black CV_8U image, at projector’s resolution.

  • whiteImage — The generated all-white CV_8U image, at projector’s resolution.

getNumberOfPatternImages()#

size_t cv::structured_light::GrayCodePattern::getNumberOfPatternImages()

Get the number of pattern images needed for the graycode pattern.

Returns

The number of pattern images needed for the graycode pattern.

getProjPixel()#

bool cv::structured_light::GrayCodePattern::getProjPixel(
InputArrayOfArrays patternImages,
int x,
int y,
Point & projPix )

For a (x,y) pixel of a camera returns the corresponding projector pixel.

The function decodes each pixel in the pattern images acquired by a camera into their corresponding decimal numbers representing the projector’s column and row, providing a mapping between camera’s and projector’s pixel.

Parameters

  • patternImages — The pattern images acquired by the camera, stored in a grayscale vector < Mat >.

  • x — x coordinate of the image pixel.

  • y — y coordinate of the image pixel.

  • projPix — Projector’s pixel corresponding to the camera’s pixel: projPix.x and projPix.y are the image coordinates of the projector’s pixel corresponding to the pixel being decoded in a camera.

setBlackThreshold()#

void cv::structured_light::GrayCodePattern::setBlackThreshold(size_t value)

Sets the value for black threshold, needed for decoding (shadowsmasks computation).

Black threshold is a number between 0-255 that represents the minimum brightness difference required for valid pixels, between the fully illuminated (white) and the not illuminated images (black); used in computeShadowMasks method.

Parameters

  • value — The desired black threshold value.

setWhiteThreshold()#

void cv::structured_light::GrayCodePattern::setWhiteThreshold(size_t value)

Sets the value for white threshold, needed for decoding.

White threshold is a number between 0-255 that represents the minimum brightness difference required for valid pixels, between the graycode pattern and its inverse images; used in getProjPixel method.

Parameters

  • value — The desired white threshold value.

Source file#

The documentation for this class was generated from the following file: