Merge pull request #334 from JUDEKEPA/master

A change in overlap setting.

Author: alexlib

openpiv/pyprocess.py

@@ -1022,8 +1022,8 @@ def extended_search_area_piv(
         search_area_size = (search_area_size, search_area_size)
 
     # verify that things are logically possible: 
-    if overlap[0] >= window_size[0] or overlap[1] >= window_size[1]:
-        raise ValueError("Overlap has to be smaller than the window_size")
+    if overlap[0] >= search_area_size[0] or overlap[1] >= search_area_size[1]:
+        raise ValueError("Overlap has to be smaller than the search_area_size")
 
     if search_area_size[0] < window_size[0] or search_area_size[1] < window_size[1]:
         raise ValueError("Search size cannot be smaller than the window_size")

openpiv/test/test_process.py

@@ -156,3 +156,26 @@ def test_fft_correlate():
     assert np.allclose(u, SHIFT_U, atol=THRESHOLD)
     assert np.allclose(v, SHIFT_V, atol=THRESHOLD)
 
+
+def test_new_overlap_setting():
+    """ test of the new overlap setting changed on 19/11/2024"""
+    frame_a, frame_b = create_pair(image_size=72)
+    u, v, _ = piv(frame_a, frame_b,
+                  window_size=16,
+                  search_area_size=32,
+                  overlap=22)
+
+    assert u.shape == (5, 5) and v.shape == (5, 5)
+
+    u, v, _ = piv(frame_a, frame_b,
+                  window_size=16,
+                  search_area_size=32,
+                  overlap=21)
+    assert u.shape == (4, 4) and v.shape == (4, 4)
+
+    u, v, _ = piv(frame_a, frame_b,
+                  window_size=16,
+                  search_area_size=32,
+                  overlap=19)
+    assert u.shape == (4, 4) and v.shape == (4, 4)
+