Handle TypeError in Live Viewer due to slow FITS files (#2476)

mantidimaging/eyes_tests/live_viewer_window_test.py

@@ -8,6 +8,7 @@
 import os
 from mantidimaging.core.operations.loader import load_filter_packages
 from mantidimaging.gui.windows.live_viewer.model import Image_Data
+from mantidimaging.gui.windows.live_viewer.presenter import ImageLoadFailError
 from mantidimaging.test_helpers.unit_test_helper import FakeFSTestCase
 from pathlib import Path
 from mantidimaging.eyes_tests.base_eyes import BaseEyesTest
@@ -73,7 +74,7 @@ def test_live_view_opens_with_data(self, _mock_time, _mock_image_watcher, mock_l
     def test_live_view_opens_with_bad_data(self, _mock_time, _mock_image_watcher, mock_load_image):
         file_list = self._make_simple_dir(self.live_directory)
         image_list = [Image_Data(path) for path in file_list]
-        mock_load_image.side_effect = ValueError
+        mock_load_image.side_effect = ImageLoadFailError(file_list[0], source_error=ValueError)
         self.imaging.show_live_viewer(self.live_directory)
         self.imaging.live_viewer_list[-1].presenter.model._handle_image_changed_in_list(image_list)
         self.check_target(widget=self.imaging.live_viewer_list[-1])

mantidimaging/gui/windows/live_viewer/model.py

@@ -54,12 +54,7 @@ def load_image(self, image: Image_Data) -> np.ndarray:
         if image in self.cache_dict.keys():
             return self.cache_dict[image]
         else:
-            try:
-                image_array = self.loading_func(image.image_path)
-            except ValueError as error:
-                message = f"{type(error).__name__} reading image: {image.image_path}: {error}"
-                LOG.error(message)
-                raise ValueError from error
+            image_array = self.loading_func(image.image_path)
             self._add_to_cache(image, image_array)
             return image_array
 

mantidimaging/gui/windows/live_viewer/presenter.py

@@ -7,11 +7,12 @@
 from collections.abc import Callable
 from logging import getLogger
 import numpy as np
-import tifffile
 from PyQt5.QtCore import pyqtSignal, QObject, QThread, QTimer
 from astropy.io import fits
 
 from imagecodecs._deflate import DeflateError
+from tifffile import tifffile
+from tifffile.tifffile import TiffFileError
 
 from mantidimaging.gui.mvp_base import BasePresenter
 from mantidimaging.gui.windows.live_viewer.model import LiveViewerWindowModel, Image_Data
@@ -25,6 +26,20 @@
 logger = getLogger(__name__)
 
 
+class ImageLoadFailError(Exception):
+    """
+    Exception raised when an image is not loaded correctly
+    """
+
+    def __init__(self, image_path: Path, source_error, message: str = '') -> None:
+        error_name = type(source_error).__name__
+        if message == '':
+            self.message = f"{error_name} :Could not load image f{image_path}, Exception: {source_error} "
+        else:
+            self.message = message
+        super().__init__(message)
+
+
 class Worker(QObject):
     finished = pyqtSignal()
 
@@ -101,9 +116,8 @@ def update_image_list(self, images_list: list[Image_Data]) -> None:
                 try:
                     image_data = self.model.image_cache.load_image(images_list[-1])
                     self.model.add_mean(images_list[-1], image_data)
-                except (OSError, KeyError, ValueError, DeflateError) as error:
-                    message = f"{type(error).__name__} reading image: {images_list[-1].image_path}: {error}"
-                    logger.error(message)
+                except ImageLoadFailError as error:
+                    logger.error(error.message)
             self.update_intensity(self.model.mean)
             self.view.set_image_range((0, len(images_list) - 1))
             self.view.set_image_index(len(images_list) - 1)
@@ -126,11 +140,10 @@ def display_image(self, image_data_obj: Image_Data) -> None:
         """
         try:
             image_data = self.model.image_cache.load_image(image_data_obj)
-        except (OSError, KeyError, ValueError, DeflateError) as error:
-            message = f"{type(error).__name__} reading image: {image_data_obj.image_path}: {error}"
-            logger.error(message)
+        except ImageLoadFailError as error:
+            logger.error(error.message)
             self.view.remove_image()
-            self.view.live_viewer.show_error(message)
+            self.view.live_viewer.show_error(error.message)
             return
         image_data = self.perform_operations(image_data)
         if image_data.size == 0:
@@ -149,15 +162,23 @@ def load_image_from_path(image_path: Path) -> np.ndarray:
         and returns as an ndarray
         """
         if image_path.suffix.lower() in [".tif", ".tiff"]:
-            with tifffile.TiffFile(image_path) as tif:
-                image_data = tif.asarray()
-            return image_data
+            try:
+                with tifffile.TiffFile(image_path) as tif:
+                    image_data = tif.asarray()
+                return image_data
+            except (OSError, KeyError, ValueError, TiffFileError, DeflateError) as err:
+                raise ImageLoadFailError(image_path, err) from err
         elif image_path.suffix.lower() == ".fits":
-            with fits.open(image_path) as fits_hdul:
-                image_data = fits_hdul[0].data
-            return image_data
+            try:
+                with fits.open(image_path) as fits_hdul:
+                    image_data = fits_hdul[0].data
+                return image_data
+            except (OSError, TypeError, ValueError) as err:
+                raise ImageLoadFailError(image_path, err) from err
         else:
-            raise ValueError(f"Unsupported file type: {image_path.suffix}")
+            raise ImageLoadFailError(image_path,
+                                     source_error=FileNotFoundError,
+                                     message=f"Unsupported file type: {image_path.suffix}")
 
     def update_image_modified(self, image_path: Path) -> None:
         """