fix(tests): add unit test for custom ROI grid spacing parameters

Closes #282

(cherry picked from commit 3bba587)

# Conflicts:
#	doc/locale/fr/LC_MESSAGES/release_notes/release_1.00.po

Author: PierreRaybaut

datalab/tests/features/image/roigrid_unit_test.py

@@ -55,6 +55,81 @@ def test_roi_grid_geometry_headless() -> None:
         assert dy == img.height / 2 * 0.5
 
 
+def test_roi_grid_custom_step() -> None:
+    """Test ROI grid with custom xstep/ystep parameters.
+
+    This test verifies the bug fix for Issue #XXX where grid ROI extraction
+    was not working correctly for images with non-uniformly distributed features
+    (e.g., laser spot arrays with gaps between spots).
+
+    The bug was that xstep and ystep parameters were missing, so users couldn't
+    adjust the spacing between ROIs when spots don't fill the entire image.
+    """
+    img = create_grid_of_gaussian_images()
+
+    # Test Case 1: Custom step to simulate tighter spacing (e.g., laser spots)
+    gp = ROIGridParam()
+    gp.nx, gp.ny = 3, 3
+    gp.xsize = gp.ysize = 20  # Small ROI size (20% of cell)
+    gp.xtranslation = gp.ytranslation = 50  # Centered
+    gp.xstep = gp.ystep = 75  # Tighter spacing (75% instead of 100%)
+    gp.xdirection = gp.ydirection = Direction.INCREASING
+
+    with qt_app_context():
+        dlg = ImageGridROIEditor(parent=None, obj=img, gridparam=gp)
+        dlg.update_obj(update_item=False)
+        roi = dlg.get_roi()
+        assert roi is not None
+        # 9 ROIs for 3x3 grid
+        assert len(list(roi)) == 9
+
+        # Verify spacing is correctly applied
+        r11 = next(r for r in roi if r.title == "ROI(1,1)")
+        r12 = next(r for r in roi if r.title == "ROI(1,2)")
+        x0_r11, _, _, _ = r11.get_physical_coords(img)
+        x0_r12, _, _, _ = r12.get_physical_coords(img)
+
+        # Expected spacing: (width / nx) * (xstep / 100)
+        expected_spacing = (img.width / gp.nx) * (gp.xstep / 100.0)
+        actual_spacing = x0_r12 - x0_r11
+
+        # Allow 1% tolerance for numerical precision
+        assert abs(actual_spacing - expected_spacing) / expected_spacing < 0.01
+
+    # Test Case 2: Different X and Y steps
+    gp2 = ROIGridParam()
+    gp2.nx, gp2.ny = 2, 2
+    gp2.xsize = gp2.ysize = 30
+    gp2.xtranslation = gp2.ytranslation = 50
+    gp2.xstep = 80  # Tighter X spacing
+    gp2.ystep = 120  # Wider Y spacing
+    gp2.xdirection = gp2.ydirection = Direction.INCREASING
+
+    with qt_app_context():
+        dlg2 = ImageGridROIEditor(parent=None, obj=img, gridparam=gp2)
+        dlg2.update_obj(update_item=False)
+        roi2 = dlg2.get_roi()
+        assert roi2 is not None
+        assert len(list(roi2)) == 4
+
+        # Verify X spacing (80%)
+        r11 = next(r for r in roi2 if r.title == "ROI(1,1)")
+        r12 = next(r for r in roi2 if r.title == "ROI(1,2)")
+        x0_r11, y0_r11, _, _ = r11.get_physical_coords(img)
+        x0_r12, _, _, _ = r12.get_physical_coords(img)
+        expected_x_spacing = (img.width / gp2.nx) * 0.8
+        actual_x_spacing = x0_r12 - x0_r11
+        assert abs(actual_x_spacing - expected_x_spacing) / expected_x_spacing < 0.01
+
+        # Verify Y spacing (120%)
+        r21 = next(r for r in roi2 if r.title == "ROI(2,1)")
+        _, y0_r21, _, _ = r21.get_physical_coords(img)
+        expected_y_spacing = (img.height / gp2.ny) * 1.2
+        actual_y_spacing = y0_r21 - y0_r11
+        assert abs(actual_y_spacing - expected_y_spacing) / expected_y_spacing < 0.01
+
+
 if __name__ == "__main__":
     test_roi_grid_geometry_headless()
+    test_roi_grid_custom_step()
     test_roi_grid(screenshots=True)

doc/locale/fr/LC_MESSAGES/release_notes/release_1.00.po

@@ -7,7 +7,7 @@ msgid ""
 msgstr ""
 "Project-Id-Version: DataLab \n"
 "Report-Msgid-Bugs-To: \n"
-"POT-Creation-Date: 2025-12-13 17:07+0100\n"
+"POT-Creation-Date: 2025-12-13 17:28+0100\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
 "Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
 "Language: fr\n"
@@ -215,6 +215,24 @@ msgstr "Correction du suffixe en double dans le titre de l'image résultante lor
 msgid "This fix is provided by Sigima 1.0.4"
 msgstr "Ce correctif est fourni par Sigima 1.0.4"
 
+msgid "**Grid ROI - Missing spacing parameters for non-uniform grids:**"
+msgstr "**ROI de grille - Paramètres d'espacement manquants pour les grilles non uniformes :**"
+
+msgid "Fixed grid ROI feature not working correctly for images where subimages don't fill the entire image area (e.g., laser spot arrays with gaps between spots)"
+msgstr "Correction de la fonctionnalité ROI de grille ne fonctionnant pas correctement pour les images où les sous-images ne remplissent pas toute la zone de l'image (par exemple, les réseaux de points laser avec des espaces entre les points)"
+
+msgid "Added missing `xstep` and `ystep` parameters to control horizontal and vertical spacing between ROI centers, as a percentage of the automatically computed cell width/height (default 100% = evenly distributed grid)"
+msgstr "Ajout des paramètres manquants `xstep` et `ystep` pour contrôler l'espacement horizontal et vertical entre les centres des ROI, en pourcentage de la largeur/hauteur de cellule calculée automatiquement (par défaut 100 % = grille uniformément répartie)"
+
+msgid "Previously, the grid was always assumed to be evenly distributed across the entire image, which failed when there was significant offset or gaps between features"
+msgstr "Auparavant, la grille était toujours supposée être uniformément répartie sur toute l'image, ce qui échouait lorsqu'il y avait un décalage ou des espaces importants entre les caractéristiques"
+
+msgid "Users can now adjust ROI spacing independently from ROI size to accurately extract grids from real-world data like laser spot arrays, diffraction patterns, or any regularly spaced features with gaps"
+msgstr "Les utilisateurs peuvent désormais ajuster l'espacement des ROI indépendamment de la taille des ROI pour extraire avec précision des grilles à partir de données réelles telles que des réseaux de points laser, des motifs de diffraction ou toute caractéristique régulièrement espacée avec des espaces"
+
+msgid "This closes [Issue #282](https://github.com/datalab-platform/datalab/issues/282) - Grid ROI Missing Spacing Parameters"
+msgstr "Ceci clôture [Issue #282](https://github.com/datalab-platform/datalab/issues/282) - Paramètres d'espacement manquants pour la ROI de grille"
+
 msgid "**Result visualization - Analysis result segments hard to see:**"
 msgstr "**Visualisation des résultats - Segments de résultats d'analyse difficiles à voir :**"
 

doc/release_notes/release_1.00.md

@@ -94,6 +94,15 @@
 * Fixed duplicate suffix in result image title when extracting radial profile from an image (e.g., `radial_profile(i019)|center=(192.500, 192.500)|center=(192.500, 192.500)` instead of `radial_profile(i019)|center=(192.500, 192.500)`)
 * This fix is provided by Sigima 1.0.4
 
+**Grid ROI - Missing spacing parameters for non-uniform grids:**
+
+* Fixed grid ROI feature not working correctly for images where subimages don't fill the entire image area (e.g., laser spot arrays with gaps between spots)
+* Added missing `xstep` and `ystep` parameters to control horizontal and vertical spacing between ROI centers, as a percentage of the automatically computed cell width/height (default 100% = evenly distributed grid)
+* Previously, the grid was always assumed to be evenly distributed across the entire image, which failed when there was significant offset or gaps between features
+* Users can now adjust ROI spacing independently from ROI size to accurately extract grids from real-world data like laser spot arrays, diffraction patterns, or any regularly spaced features with gaps
+* This fix is provided by Sigima 1.0.4
+* This closes [Issue #282](https://github.com/datalab-platform/datalab/issues/282) - Grid ROI Missing Spacing Parameters
+
 **Result visualization - Analysis result segments hard to see:**
 
 * Fixed analysis result markers (FWHM, pulse features, etc.) being difficult or impossible to see on signal plots