fix: gridify() IndexError from numpy float // int staying float64

src/machinevisiontoolbox/ImagePointFeatures.py

@@ -296,8 +296,8 @@ def gridify(self, nbins: int | tuple[int, int], nfeat: int) -> "BaseFeature2D":
         bins = np.zeros((nh, nw), dtype="int")
 
         for f in self:
-            ix = f.p[0] // binwidth
-            iy = f.p[1] // binheight
+            ix = int(f.p[0].item() // binwidth)
+            iy = int(f.p[1].item() // binheight)
 
             if bins[iy, ix] < nfeat:
                 keep.append(f)

tests/test_image_point_features.py

@@ -190,6 +190,26 @@ def test_features_list_operations(self):
         except:
             pass
 
+    def test_gridify_scalar_nbins(self):
+        """gridify() with a scalar nbins must not raise (regression: numpy
+        float // int stayed float64, bins[iy, ix] then rejected as an index)"""
+        img = Image.Read("monalisa.png", mono=True)
+        sift = img.SIFT()
+        self.assertGreater(len(sift), 0)
+
+        gridded = sift.gridify(nbins=4, nfeat=2)
+        self.assertLessEqual(len(gridded), len(sift))
+
+    def test_gridify_tuple_nbins(self):
+        """gridify() with a (nw, nh) tuple must not raise, same root cause
+        as the scalar case above."""
+        img = Image.Read("monalisa.png", mono=True)
+        sift = img.SIFT()
+        self.assertGreater(len(sift), 0)
+
+        gridded = sift.gridify(nbins=(4, 3), nfeat=2)
+        self.assertLessEqual(len(gridded), len(sift))
+
     def test_feature_properties(self):
         """Test feature properties"""
         img = Image.Read("monalisa.png", mono=True)