fix bugs

Author: Czaki

package/PartSegImage/image.py

@@ -1042,7 +1042,7 @@ def _name_to_rgb(name: str) -> tuple[int, int, int]:
 def _rgb_to_signed_int(rgb: tuple[int, int, int]) -> int:
     """Convert an RGB tuple to a signed integer representation."""
     r, g, b = rgb[:3]
-    return np.uint32((r << 24) | (g << 16) | (b << 8) | 255).view(np.int32).item()
+    return (np.int32(r) << 24) | (np.int32(g) << 16) | (np.int32(b) << 8) | 255
 
 
 try:

package/PartSegImage/image_reader.py

@@ -135,6 +135,13 @@ def __init__(self, callback_function: typing.Optional[typing.Callable[[str, int]
             self.callback_function = callback_function
 
     def _get_channel_info(self) -> list[ChannelInfo]:
+        if (
+            len(self.ranges) == 1
+            and isinstance(self.colors, np.ndarray)
+            and self.colors.ndim == 2
+            and self.colors.shape[0] > 1
+        ):
+            return [ChannelInfo(name=self.channel_names[0], color_map=self.colors, contrast_limits=self.ranges[0])]
         return [
             ChannelInfo(name=name, color_map=color, contrast_limits=contrast_limits)
             for name, color, contrast_limits in zip_longest(self.channel_names, self.colors, self.ranges)
@@ -593,7 +600,7 @@ def read_resolution_from_tags(self, image_file):
     def _read_imagej_colors(image_file):
         colors = image_file.imagej_metadata.get("LUTs", [])
         if isinstance(colors, list) and colors and colors[0].shape[0] == 24:
-            # drop buggy colors that comes from bug in PArtSeg with
+            # drop buggy colors that comes from bug in PartSeg with
             # writing 64 bit integers in tifffile
             return []
         return colors

package/tests/test_PartSegImage/test_image_writer.py

@@ -111,7 +111,9 @@ def data_to_save():
             ChannelInfo(name="ch3", color_map="#FB1", contrast_limits=(0, 25)),
             ChannelInfo(name="ch4", color_map=(0, 180, 0), contrast_limits=(0, 22)),
             ChannelInfo(
-                name="ch5", color_map=np.linspace((0, 0, 0), (128, 255, 0), num=256).T, contrast_limits=(0, 20)
+                name="ch5",
+                color_map=np.linspace((0, 0, 0), (128, 255, 0), num=256, dtype=np.uint8).T,
+                contrast_limits=(0, 20),
             ),
         ],
     )