Updated warning and added news fragment

astropy · Feb 17, 2023 · 4556b49 · 4556b49
1 parent 9445c4a
commit 4556b49
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Showing 2 changed files with 9 additions and 5 deletions.
diff --git a/astropy/io/fits/hdu/compressed.py b/astropy/io/fits/hdu/compressed.py
@@ -1129,11 +1129,12 @@ def _update_header_data(
                     )
 
             if tile_size != original_tile_size:
-                warnings.warn(f"The data size should be a multiple of the tile "
-                            f"size. The tile size has automatically been changed "
-                            f"from {original_tile_size} to {tile_size}, but in "
-                            f"future this will raise an error and the correct tile "
-                            f"size should be specified directly.", AstropyDeprecationWarning)
+                warnings.warn(f"The tile size should be such that no tiles have "
+                              f"fewer than 4 pixels. The tile size has "
+                              f"automatically been changed from {original_tile_size} "
+                              f"to {tile_size}, but in future this will raise an "
+                              f"error and the correct tile size should be specified "
+                              f"directly.", AstropyDeprecationWarning)
 
         # Set up locations for writing the next cards in the header.
         last_znaxis = "ZNAXIS"

diff --git a/docs/changes/io.fits/14410.api.rst b/docs/changes/io.fits/14410.api.rst
@@ -0,0 +1,3 @@
+Deprecate the auto-fixing of tile sizes for HCOMPRESS_1 tiled
+image compression when the tile size could be changed by +1
+to make it acceptable.