3d removal of background

https://www.notion.so/qim-dtu/3D-remove-background-function-fac8e64da886429eacd9520bc7be0610?pvs=4

implemented into existing filters framework

qim3d/processing/operations.py

+import numpy as np
+import qim3d.processing.filters as filters
+
+
+def remove_background(
+    vol: np.ndarray,
+    median_filter_size: int = 2,
+    min_object_radius: int = 3,
+    background: str = "dark",
+    **median_kwargs
+) -> np.ndarray:
+    """
+    Remove background from a volume using a qim3d filters.
+
+    Args:
+        vol (np.ndarray): The volume to remove background from.
+        median_filter_size (int, optional): The size of the median filter. Defaults to 2.
+        min_object_radius (int, optional): The radius of the structuring element for the tophat filter. Defaults to 3.
+        background (str, optional): The background type. Can be 'dark' or 'bright'. Defaults to 'dark'.
+        **median_kwargs: Additional keyword arguments for the Median filter.
+
+    Returns:
+        np.ndarray: The volume with background removed.
+
+
+    Example:
+        ```python
+        import qim3d
+
+        vol = qim3d.examples.cement_128x128x128
+        qim3d.viz.slices(vol, vmin=0, vmax=255)
+        ```
+        ![operations-remove_background_before](assets/screenshots/operations-remove_background_before.png)  
+
+        ```python
+        vol_filtered  = qim3d.processing.operations.remove_background(vol,
+                                                              min_object_radius=3, 
+                                                              background="bright")
+        qim3d.viz.slices(vol_filtered, vmin=0, vmax=255)
+        ```
+        ![operations-remove_background_after](assets/screenshots/operations-remove_background_after.png)
+    """
+
+    # Create a pipeline with a median filter and a tophat filter
+    pipeline = filters.Pipeline(
+        filters.Median(size=median_filter_size, **median_kwargs),
+        filters.Tophat(radius=min_object_radius, background=background),
+    )
+
+    # Apply the pipeline to the volume
+    return pipeline(vol)