Implementing uint16 reading with tifffile

src/gui/tabs/training_tab.py

@@ -1303,6 +1303,14 @@ class TrainingTab(QWidget):
         sample_image = self._find_first_image(images_dir)
         if not sample_image:
             return False
+
+        # Do not force an RGB cache for TIFF datasets.
+        # We handle grayscale/16-bit TIFFs via runtime Ultralytics patches that:
+        # - load TIFFs with `tifffile`
+        # - replicate grayscale to 3 channels without quantization
+        # - normalize uint16 correctly during training
+        if sample_image.suffix.lower() in {".tif", ".tiff"}:
+            return False
         try:
             img = Image(sample_image)
             return img.pil_image.mode.upper() != "RGB"