diff --git a/lisp/emacs-lisp/timer.el b/lisp/emacs-lisp/timer.el
index 561cc70078..48301fd4fd 100644
--- a/lisp/emacs-lisp/timer.el
+++ b/lisp/emacs-lisp/timer.el
@@ -488,6 +488,48 @@ y-or-n-p-with-timeout
 If the user does not answer after SECONDS seconds, return DEFAULT-VALUE."
   (with-timeout (seconds default-value)
     (y-or-n-p prompt)))
+
+(defmacro debounce (secs function)
+  "Call FUNCTION after SECS seconds have elapsed.
+Postpone FUNCTION call until after SECS seconds have elapsed since the
+last time it was invoked.  On consecutive calls within the interval of
+SECS seconds, cancel all previous calls and in quick succession execute
+only the last call."
+  (declare (indent 1) (debug t))
+  (let ((timer-sym (make-symbol "timer")))
+    `(let (,timer-sym)
+       (lambda (&rest args)
+         (when (timerp ,timer-sym)
+           (cancel-timer ,timer-sym))
+         (setq ,timer-sym
+               (run-with-timer
+                ,secs nil (lambda ()
+                            (apply ,function args))))))))
+
+(defmacro debounce-reduce (secs state-function function)
+  "Call FUNCTION after SECS seconds have elapsed.
+Postpone FUNCTION call until after SECS seconds have elapsed since the
+last time it was invoked.  On consecutive calls within the interval of
+SECS seconds, cancel all previous calls and in quick succession execute
+only the last call.
+STATE-FUNCTION can be used to calculate the state on consecutive calls,
+and execute the last call with the collected state."
+  (declare (indent 1) (debug t))
+  (let ((timer-sym (make-symbol "timer"))
+        (state-sym (make-symbol "state")))
+    `(let (,timer-sym ,state-sym)
+       (lambda (&rest args)
+         (setq ,state-sym (apply ,state-function ,state-sym args))
+         (when (timerp ,timer-sym)
+           (cancel-timer ,timer-sym))
+         (setq ,timer-sym
+               (run-with-timer
+                ,secs nil (lambda ()
+                            (apply ,function (if (listp ,state-sym)
+                                                 ,state-sym
+                                               (list ,state-sym)))
+                            (setq ,state-sym nil))))))))
+
 
 (defconst timer-duration-words
   (list (cons "microsec" 0.000001)
diff --git a/lisp/image.el b/lisp/image.el
index e0965c1091..d57ae3a720 100644
--- a/lisp/image.el
+++ b/lisp/image.el
@@ -1016,18 +1016,20 @@ image-increase-size
 If N is 3, then the image size will be increased by 30%.  The
 default is 20%."
   (interactive "P")
-  (image--change-size (if n
-                          (1+ (/ (prefix-numeric-value n) 10.0))
-                        1.2)))
+  (funcall image--change-size
+           (if n
+               (1+ (/ (prefix-numeric-value n) 10.0))
+             1.2)))
 
 (defun image-decrease-size (&optional n)
   "Decrease the image size by a factor of N.
 If N is 3, then the image size will be decreased by 30%.  The
 default is 20%."
   (interactive "P")
-  (image--change-size (if n
-                          (- 1 (/ (prefix-numeric-value n) 10.0))
-                        0.8)))
+  (funcall image--change-size
+           (if n
+               (- 1 (/ (prefix-numeric-value n) 10.0))
+             0.8)))
 
 (defun image-mouse-increase-size (&optional event)
   "Increase the image size using the mouse."
@@ -1062,12 +1064,16 @@ image--get-imagemagick-and-warn
       (plist-put (cdr image) :type 'imagemagick))
     image))
 
-(defun image--change-size (factor)
-  (let* ((image (image--get-imagemagick-and-warn))
-         (new-image (image--image-without-parameters image))
-         (scale (image--current-scaling image new-image)))
-    (setcdr image (cdr new-image))
-    (plist-put (cdr image) :scale (* scale factor))))
+(defvar image--change-size
+  (debounce-reduce 0.3
+    (lambda (state factor)
+      (* (or state 1) factor))
+    (lambda (factor)
+      (let* ((image (image--get-imagemagick-and-warn))
+             (new-image (image--image-without-parameters image))
+             (scale (image--current-scaling image new-image)))
+        (setcdr image (cdr new-image))
+        (plist-put (cdr image) :scale (* scale factor))))))
 
 (defun image--image-without-parameters (image)
   (cons (pop image)