diff --git a/monai/data/image_writer.py b/monai/data/image_writer.py index cc6cdcdead..ad69455b2b 100644 --- a/monai/data/image_writer.py +++ b/monai/data/image_writer.py @@ -116,7 +116,18 @@ def resolve_writer(ext_name, error_if_not_found=True) -> Sequence: except Exception: # other writer init errors indicating it exists avail_writers.append(_writer) if not avail_writers and error_if_not_found: - raise OptionalImportError(f"No ImageWriter backend found for {fmt}.") + hints = { + "png": "pip install pillow", + "jpg": "pip install pillow", + "jpeg": "pip install pillow", + "nii": "pip install nibabel", + "nii.gz": "pip install nibabel", + "dcm": "pip install itk", + } + hint = hints.get(fmt.lstrip(".").lower(), "pip install pillow or pip install nibabel") + raise OptionalImportError( + f"No ImageWriter backend found for {fmt}. Try: {hint}." + ) writer_tuple = ensure_tuple(avail_writers) SUPPORTED_WRITERS[fmt] = writer_tuple return writer_tuple