Function infer_group_from_folder 

pub fn infer_group_from_folder(image_path: &str) -> Option<String>

Infer the group name from an image folder path.

Extracts the group from folder names like “train2017”, “val2017”, “test2017”. Strips trailing year numbers to get the group name.

Examples

• train2017/000000001.jpg → “train”
• val2017/000000002.jpg → “val”
• test2017/000000003.jpg → “test”
• custom_split/image.jpg → “custom_split”

Arguments

• image_path - Relative path to the image (e.g., “train2017/000000001.jpg”)

Returns

Inferred group name, or None if no folder component is found.