fix: Fix rendering of alternative representation if there are more components in the alternative representation than in ROI

package/PartSeg/common_gui/napari_image_view.py

@@ -483,8 +483,10 @@ def get_roi_view_parameters(self, image_info: ImageInfo) -> ColorInfo:
             or colors.size == 0
         ):
             return {0: [0, 0, 0, 0], None: [0, 0, 0, 0]}
-
-        res = {x: colors[(x - 1) % colors.shape[0]] for x in range(1, image_info.roi_count + 1)}
+        res = {
+            x: colors[(x - 1) % colors.shape[0]]
+            for x in range(1, image_info.roi_info.get_components_num(self.roi_alternative_selection) + 1)
+        }
         res[0] = [0, 0, 0, 0]
         res[None] = [0, 0, 0, 0]
         return res

package/PartSegCore/roi_info.py

@@ -62,6 +62,7 @@
         self.roi = roi
         self.bound_info = self.calc_bounds(roi)
         self.sizes = np.bincount(roi.flat)
+        self._alternative_component_size = {}
 
     def fit_to_image(self, image: Image) -> "ROIInfo":
         if self.roi is None:
@@ -70,6 +71,13 @@
         alternatives = {k: image.fit_array_to_image(v) for k, v in self.alternative.items()}
         return ROIInfo(roi, self.annotations, alternatives)
 
+    def get_components_num(self, name):
+        if name == "ROI" or name not in self.alternative:
+            return max(self.bound_info)
+        if name not in self._alternative_component_size:
+            self._alternative_component_size[name] = np.max(self.alternative[name])
+        return self._alternative_component_size[name]
+
     def __str__(self):
         return f"ROIInfo; components: {len(self.bound_info)}, sizes: {self.sizes}"