Add a new `image-transform-smoothing' user option

* doc/lispref/display.texi (Image Descriptors): Document it.
* lisp/image.el (image-transform-smoothing): New user option.
(create-image): Use it.
(image--default-smoothing): New function.

1 files changed, 6 insertions, 0 deletions

diff --git a/etc/NEWS b/etc/NEWS
index 4b8700a01cc..fa8784db59c 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1483,6 +1483,12 @@ and nil to disable smoothing.
 The default behaviour of smoothing on down-scaling and not smoothing
 on up-scaling remains unchanged.
 
++++
+*** New user option 'image-transform-smoothing'.
+This controls whether to use smoothing or not for an image.  Values
+include nil (no smoothing), t (do smoothing) or a predicate function
+that's called with the image object and should return nil/t.
+
 ** EWW
 
 +++