org.opencv.structured_light

Class GrayCodePattern

java.lang.Object

org.opencv.core.Algorithm

org.opencv.structured_light.StructuredLightPattern

org.opencv.structured_light.GrayCodePattern

public class GrayCodePattern
extends StructuredLightPattern

Class implementing the Gray-code pattern, based on CITE: 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.

Field Summary

Fields inherited from class org.opencv.core.Algorithm

nativeObj

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	GrayCodePattern(long addr)

Method Summary

Modifier and Type	Method and Description
static GrayCodePattern	__fromPtr__(long addr)
static GrayCodePattern	create(int width, int height) Constructor
protected void	finalize()
void	getImagesForShadowMasks(Mat blackImage, Mat whiteImage) Generates the all-black and all-white images needed for shadowMasks computation.
long	getNumberOfPatternImages() Get the number of pattern images needed for the graycode pattern.
boolean	getProjPixel(List<Mat> patternImages, int x, int y, Point projPix) For a (x,y) pixel of a camera returns the corresponding projector pixel.
void	setBlackThreshold(long value) Sets the value for black threshold, needed for decoding (shadowsmasks computation).
void	setWhiteThreshold(long value) Sets the value for white threshold, needed for decoding.

Methods inherited from class org.opencv.structured_light.StructuredLightPattern

generate

Methods inherited from class org.opencv.core.Algorithm

clear, empty, getDefaultName, getNativeObjAddr, save

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GrayCodePattern

protected GrayCodePattern(long addr)

Method Detail

__fromPtr__

public static GrayCodePattern __fromPtr__(long addr)

create

public static GrayCodePattern create(int width,
                                     int height)

Constructor

Parameters:

width - automatically generated

height - automatically generated

Returns:

automatically generated

getNumberOfPatternImages

public long getNumberOfPatternImages()

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

Returns:

The number of pattern images needed for the graycode pattern.

setWhiteThreshold

public void setWhiteThreshold(long 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.

setBlackThreshold

public void setBlackThreshold(long 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.

getImagesForShadowMasks

public void getImagesForShadowMasks(Mat blackImage,
                                    Mat 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.

getProjPixel

public boolean getProjPixel(List<Mat> 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.

Returns:

automatically generated

finalize

protected void finalize()
                 throws Throwable

Overrides:

finalize in class StructuredLightPattern

Throws:

Throwable