Issue : Missing Error Handling for Image Opening in `ImageDataset`

The `ImageDataset` class opens images using `Image.open(impath)`. However, it lacks error handling for cases where the image file is corrupted or doesn't exist. This can lead to program crashes during training or validation. Add a `try-except` block to handle potential `FileNotFoundError` or `PIL.UnidentifiedImageError` exceptions and log the error. Consider skipping the problematic image or raising an exception to halt execution, depending on the desired behavior.