Three mainstream line detectors: lsd-lines, ed-lines and hough-lines

• segment line detector (lsd)
• edge drawing line detector (edlines)
• hough line detector (standard and probabilistic)

All original dependencies have been removed. Code could be run independently:

• line segment detector with a scale in vertical and horizontal direction in boundingbox, respectively
• edge drawing line detector with a scale in vertical and horizontal direction in boundingbox, respectively
• hough line detector(standard and probabilistic) with a scale in vertical and horizontal direction in boundingbox, respectively

EDLines

EDLines Simple Interface with Scale in Boundingbox

@param src         				image,single channel.

@param w           				width of image.

@param h           				height of image.

@param scaleX      				downscale factor in X-axis.

@param scaleY      				downscale factor in Y-axis.

@param bbox        				boundingbox to detect.

@param lines      				result.

@return            				0:ok; 1:error
int EdgeDrawingLineDetector(unsigned char *src, int w, int h,float scaleX, scaleY, boundingbox_t bbox, std::vector<line_float_t> &lines);

LSD

LSD Simple Interface with Scale in Boundingbox

@param src         				image,single channel.

@param w           				width of image.

@param h           				height of image.

@param scaleX      				downscale factor in X-axis.

@param scaleY      				downscale factor in Y-axis.

@param bbox       			 	boundingbox to detect.

@param lines       				result.

@return            				0:ok; 1:error
int LsdLineDetector(unsigned char *src, int w, int h, float scaleX, float scaleY, boundingbox_t bbox, std::vector<line_float_t> &lines);

Houghline

Houghline Simple Interface with Scale in Boundingbox

@param src         				image,single channel.

@param w           				width of image.

@param h           				height of image.

@param scaleX      			 	downscale factor in X-axis.

@param scaleY      			 	downscale factor in Y-axis.

@param canny_low_thresh      	lower threshold for the hysteresis procedure in canny operator.

@param canny_high_thresh      	higher threshold for the hysteresis procedure in canny operator.

@param hough_rho      			distance resolution of the accumulator in pixels.

@param hough_theta      		angle resolution of the accumulator in radians.

@param min_theta_linelength     standard: for standard and multi-scale hough transform, minimum angle to check for lines; propabilistic: minimum line length. Line segments shorter than that are rejected.

@param max_theta_gap      		standard: for standard and multi-scale hough transform, maximum angle to check for lines; propabilistic: maximum allowed gap between points on the same line to link them.

@param hough_thresh      		accumulator threshold parameter. only those lines are returned that get enough votes ( >threshold ).

@param _type      				hough line method: HOUGH_LINE_STANDARD or HOUGH_LINE_PROBABILISTIC

@param bbox        				boundingbox to detect.

@param lines       				result.

@return            				0:ok; 1:error
int HoughLineDetector(unsigned char *src, int w, int h, float scaleX, float scaleY, float CannyLowThresh, float CannyHighThresh, float HoughRho, float HoughTheta, float MinThetaLinelength, float MaxThetaGap, int HoughThresh, HOUGH_LINE_TYPE_CODE _type, boundingbox_t bbox, std::vector<line_float_t> &lines);

Reference

• LSD: A Line Segment Detector
• LBD_Descriptor
• OpenCV