Merge pull request matplotlib#23168 from SaumyaBhushan/Issue#23050

DOC: Corrected docstring for artist.Artist.set_agg_filter

Author: tacaswell

lib/matplotlib/artist.py

@@ -934,11 +934,13 @@ def set_agg_filter(self, filter_func):
         Parameters
         ----------
         filter_func : callable
-            A filter function, which takes a (m, n, 3) float array and a dpi
-            value, and returns a (m, n, 3) array.
+            A filter function, which takes a (m, n, depth) float array
+            and a dpi value, and returns a (m, n, depth) array and two
+            offsets from the bottom left corner of the image
 
             .. ACCEPTS: a filter function, which takes a (m, n, 3) float array
-                and a dpi value, and returns a (m, n, 3) array
+                and a dpi value, and returns a (m, n, 3) array and two offsets
+                from the bottom left corner of the image
         """
         self._agg_filter = filter_func
         self.stale = True