Added ArUco marker size check for Aruco and Charuco boards.

doc/pattern_tools/gen_pattern.py

@@ -186,6 +186,8 @@ class PatternMaker:
         yspacing = (self.height - self.rows * self.square_size) / 2.0
 
         ch_ar_border = (self.square_size - self.aruco_marker_size)/2
+        if ch_ar_border < side*0.7:
+            print("Marker border {} is less than 70% of ArUco pin size {}. Please increase --square_size or decrease --marker_size for stable board detection".format(ch_ar_border, int(side)))
         marker_id = 0
         for y in range(0, self.rows):
             for x in range(0, self.cols):
@@ -283,6 +285,9 @@ def main():
             else:
                 raise ValueError("The marker {},{} is outside the checkerboard".format(x, y))
 
+    if p_type == "charuco_board" and aruco_marker_size >= square_size:
+        raise ValueError("ArUco markers size must be smaller than square size")
+
     pm = PatternMaker(columns, rows, output, units, square_size, radius_rate, page_width, page_height, markers, aruco_marker_size, dict_file)
     # dict for easy lookup of pattern type
     mp = {"circles": pm.make_circles_pattern, "acircles": pm.make_acircles_pattern,

modules/objdetect/src/aruco/aruco_board.cpp

@@ -3,6 +3,7 @@
 // of this distribution and at http://opencv.org/license.html
 
 #include "../precomp.hpp"
+#include <opencv2/core/utils/logger.hpp>
 #include "opencv2/objdetect/aruco_board.hpp"
 
 #include <opencv2/objdetect/aruco_dictionary.hpp>
@@ -250,7 +251,11 @@ GridBoard::GridBoard() {}
 GridBoard::GridBoard(const Size& size, float markerLength, float markerSeparation,
                      const Dictionary &dictionary, InputArray ids):
     Board(new GridBoardImpl(dictionary, size, markerLength, markerSeparation)) {
-
+    float onePin = markerLength / ((float)(dictionary.markerSize+2));
+    if (markerSeparation < onePin*.7f) {
+        CV_LOG_WARNING(NULL, "Marker border " << markerSeparation << " is less than 70% of ArUco pin size "
+            << onePin << ". Please increase markerSeparation or decrease markerLength for stable board detection");
+    }
     size_t totalMarkers = (size_t) size.width*size.height;
     CV_Assert(ids.empty() || totalMarkers == ids.total());
     vector<vector<Point3f> > objPoints;
@@ -541,7 +546,12 @@ CharucoBoard::CharucoBoard(const Size& size, float squareLength, float markerLen
     Board(new CharucoBoardImpl(dictionary, size, squareLength, markerLength)) {
 
     CV_Assert(size.width > 1 && size.height > 1 && markerLength > 0 && squareLength > markerLength);
-
+    float onePin = markerLength / ((float)(dictionary.markerSize+2));
+    float markerSeparation = (squareLength - markerLength)/2.f;
+    if (markerSeparation < onePin*.7f) {
+        CV_LOG_WARNING(NULL, "Marker border " << markerSeparation << " is less than 70% of ArUco pin size "
+            << onePin <<". Please increase markerSeparation or decrease markerLength for stable board detection");
+    }
     ids.copyTo(impl->ids);
 
     static_pointer_cast<CharucoBoardImpl>(impl)->createCharucoBoard();