t/calibration: Add support for findChessboardCornersSB

src/xrt/auxiliary/tracking/t_calibration.cpp

@@ -14,6 +14,7 @@
 #include "util/u_debug.h"
 #include "util/u_frame.h"
 #include "util/u_format.h"
+#include "util/u_logging.h"
 
 #include "tracking/t_tracking.h"
 #include "tracking/t_calibration_opencv.hpp"
@@ -22,6 +23,13 @@
 #include <sys/stat.h>
 #include <utility>
 
+#if CV_MAJOR_VERSION >= 4
+#define SB_CHEESBOARD_CORNERS_SUPPORTED
+#if CV_MINOR_VERSION >= 3 || CV_MAJOR_VERSION > 4
+#define SB_CHEESBOARD_CORNERS_MARKER_SUPPORTED
+#endif
+#endif
+
 
 DEBUG_GET_ONCE_BOOL_OPTION(hsv_filter, "T_DEBUG_HSV_FILTER", false)
 DEBUG_GET_ONCE_BOOL_OPTION(hsv_picker, "T_DEBUG_HSV_PICKER", false)
@@ -99,6 +107,8 @@ public:
 		cv::Size dims = {8, 6};
 		enum t_board_pattern pattern = T_BOARD_CHECKERS;
 		float spacing_meters = 0.05;
+		bool marker;          //!< Center board marker for sb_checkers.
+		bool normalize_image; //!< For SB checkers.
 	} board;
 
 	struct
@@ -325,6 +335,45 @@ do_view_chess(class Calibration &c, struct ViewState &view, cv::Mat &gray, cv::M
 	return found;
 }
 
+#ifdef SB_CHEESBOARD_CORNERS_SUPPORTED
+static bool
+do_view_sb_checkers(class Calibration &c, struct ViewState &view, cv::Mat &gray, cv::Mat &rgb)
+{
+	/*
+	 * Fisheye requires measurement and model to be double, other functions
+	 * requires them to be floats (like cornerSubPix). So we give in
+	 * current_f32 here and convert below.
+	 */
+
+	int flags = 0;
+	if (c.board.normalize_image) {
+		flags += cv::CALIB_CB_NORMALIZE_IMAGE;
+	}
+
+#ifdef SB_CHEESBOARD_CORNERS_MARKER_SUPPORTED
+	if (c.board.marker) {
+		// Only available in OpenCV 4.3 and above.
+		flags += cv::CALIB_CB_MARKER;
+	}
+#endif
+
+	bool found = cv::findChessboardCornersSB(gray,             // Image
+	                                         c.board.dims,     // patternSize
+	                                         view.current_f32, // corners
+	                                         flags);           // flags
+
+	// Do the conversion here.
+	view.current_f64.clear(); // Doesn't effect capacity.
+	for (const cv::Point2f &p : view.current_f32) {
+		view.current_f64.emplace_back(double(p.x), double(p.y));
+	}
+
+	do_view_coverage(c, view, gray, rgb, found);
+
+	return found;
+}
+#endif
+
 static bool
 do_view_circles(class Calibration &c, struct ViewState &view, cv::Mat &gray, cv::Mat &rgb)
 {
@@ -364,6 +413,11 @@ do_view(class Calibration &c, struct ViewState &view, cv::Mat &gray, cv::Mat &rg
 	case T_BOARD_CHECKERS: //
 		found = do_view_chess(c, view, gray, rgb);
 		break;
+#ifdef SB_CHEESBOARD_CORNERS_SUPPORTED
+	case T_BOARD_SB_CHECKERS: //
+		found = do_view_sb_checkers(c, view, gray, rgb);
+		break;
+#endif
 	case T_BOARD_CIRCLES: //
 		found = do_view_circles(c, view, gray, rgb);
 		break;
@@ -405,6 +459,7 @@ build_board_position(class Calibration &c)
 
 	switch (c.board.pattern) {
 	case T_BOARD_CHECKERS:
+	case T_BOARD_SB_CHECKERS:
 	case T_BOARD_CIRCLES:
 		// Nothing to do.
 		break;
@@ -416,6 +471,7 @@ build_board_position(class Calibration &c)
 
 	switch (c.board.pattern) {
 	case T_BOARD_CHECKERS:
+	case T_BOARD_SB_CHECKERS:
 	case T_BOARD_CIRCLES:
 		c.board.model_f32.reserve(rows_num * cols_num);
 		c.board.model_f64.reserve(rows_num * cols_num);
@@ -1217,6 +1273,19 @@ t_calibration_stereo_create(struct xrt_frame_context *xfctx,
                             struct xrt_frame_sink *gui,
                             struct xrt_frame_sink **out_sink)
 {
+#ifndef SB_CHEESBOARD_CORNERS_SUPPORTED
+	if (params->pattern == T_BOARD_SB_CHECKERS) {
+		U_LOG_E("OpenCV %u.%u doesn't support SB chessboard!", CV_MAJOR_VERSION, CV_MINOR_VERSION);
+		return -1;
+	}
+#endif
+#ifndef SB_CHEESBOARD_CORNERS_MARKER_SUPPORTED
+	if (params->pattern == T_BOARD_SB_CHECKERS && params->sb_checkers.marker) {
+		U_LOG_W("OpenCV %u.%u doesn't support SB chessboard marker option!", CV_MAJOR_VERSION,
+		        CV_MINOR_VERSION);
+	}
+#endif
+
 	auto &c = *(new Calibration());
 
 	// Basic setup.
@@ -1238,6 +1307,15 @@ t_calibration_stereo_create(struct xrt_frame_context *xfctx,
 		c.subpixel_enable = params->checkers.subpixel_enable;
 		c.subpixel_size = params->checkers.subpixel_size;
 		break;
+	case T_BOARD_SB_CHECKERS:
+		c.board.dims = {
+		    params->sb_checkers.cols,
+		    params->sb_checkers.rows,
+		};
+		c.board.spacing_meters = params->sb_checkers.size_meters;
+		c.board.marker = params->sb_checkers.marker;
+		c.board.normalize_image = params->sb_checkers.normalize_image;
+		break;
 	case T_BOARD_CIRCLES:
 		c.board.dims = {
 		    params->circles.cols,
@@ -1307,6 +1385,8 @@ t_calibration_stereo_create(struct xrt_frame_context *xfctx,
 		push_model(c);
 	}
 #endif
+
+
 	return ret;
 }
 

src/xrt/auxiliary/tracking/t_tracking.h

@@ -351,6 +351,8 @@ t_slam_start(struct xrt_tracked_slam *xts);
 enum t_board_pattern
 {
 	T_BOARD_CHECKERS,
+	//! Sector based checker board, using `cv::findChessboardCornersSB`.
+	T_BOARD_SB_CHECKERS,
 	T_BOARD_CIRCLES,
 	T_BOARD_ASYMMETRIC_CIRCLES,
 };
@@ -390,6 +392,16 @@ struct t_calibration_params
 		int subpixel_size;
 	} checkers;
 
+	struct
+	{
+		int cols;
+		int rows;
+		float size_meters;
+
+		bool marker;
+		bool normalize_image;
+	} sb_checkers;
+
 	struct
 	{
 		int cols;
@@ -446,6 +458,13 @@ t_calibration_params_default(struct t_calibration_params *p)
 	p->checkers.subpixel_enable = true;
 	p->checkers.subpixel_size = 5;
 
+	// Sector based checker board.
+	p->sb_checkers.cols = 14;
+	p->sb_checkers.rows = 9;
+	p->sb_checkers.size_meters = 0.01206f;
+	p->sb_checkers.marker = false;
+	p->sb_checkers.normalize_image = false;
+
 	// Symmetrical circles.
 	p->circles.cols = 9;
 	p->circles.rows = 7;

src/xrt/state_trackers/gui/gui_scene_calibrate.c

@@ -273,7 +273,7 @@ scene_render_select(struct gui_scene *scene, struct gui_program *p)
 	igInputInt("Collect in groups of #", &cs->params.num_collect_restart, 1, 5, 0);
 
 	igSeparator();
-	igComboStr("Board type", (int *)&cs->params.pattern, "Checkers\0Circles\0Asymetric Circles\0\0", 3);
+	igComboStr("Board type", (int *)&cs->params.pattern, "Checkers\0Corners SB\0Circles\0Asymetric Circles\0\0", 3);
 	switch (cs->params.pattern) {
 	case T_BOARD_CHECKERS:
 		igInputInt("Checkerboard Rows", &cs->params.checkers.rows, 1, 5, 0);
@@ -282,6 +282,13 @@ scene_render_select(struct gui_scene *scene, struct gui_program *p)
 		igCheckbox("Subpixel", &cs->params.checkers.subpixel_enable);
 		igInputInt("Subpixel Search Size", &cs->params.checkers.subpixel_size, 1, 5, 0);
 		break;
+	case T_BOARD_SB_CHECKERS:
+		igInputInt("Internal Corner Rows", &cs->params.sb_checkers.rows, 1, 5, 0);
+		igInputInt("Internal Corner Columns", &cs->params.sb_checkers.cols, 1, 5, 0);
+		igInputFloat("Corner Spacing (m)", &cs->params.sb_checkers.size_meters, 0.0005, 0.001, NULL, 0);
+		igCheckbox("Marker", &cs->params.sb_checkers.marker);
+		igCheckbox("Normalize image", &cs->params.sb_checkers.normalize_image);
+		break;
 	case T_BOARD_CIRCLES:
 		igInputInt("Circle Rows", &cs->params.circles.rows, 1, 5, 0);
 		igInputInt("Circle Columns", &cs->params.circles.cols, 1, 5, 0);