Copy images in buffer

Question

I'd like to copy part of a buffer including all images. The code below copies the text but not the image. How do I copy images and how do I search for images in a buffer?

(insert
 (with-current-buffer (get-buffer-create "buf")
   (insert "-->")
   (put-image (find-image '((:type jpeg :file "~/foo.jpg")))
              (point))
   (insert "<--")
   (buffer-substring (point-min) (point-max))))

Answer 1

I think I found a solution. You need copy-overlay and move-overlay to copy an overlay to another buffer:

(defun my-copy-buf (buf)
  (let* ((beg (with-current-buffer buf (point-min)))
         (end (with-current-buffer buf (point-max)))
         (ovs (with-current-buffer buf (overlays-in beg end))))
    (save-excursion
      (insert-buffer-substring buf beg end))
    (dolist (ov ovs)
      (move-overlay (copy-overlay ov)
                    (1- (+ (point) (overlay-start ov)))
                    (1- (+ (point) (overlay-end ov)))
                    (current-buffer))
      )))

(progn
  (with-current-buffer (get-buffer-create "tmp-buffer")
    (insert "-->")
    (put-image (find-image '((:type jpeg :file "~/foo.jpg")))
               (point))
    (insert "<--"))
  (my-copy-buf "tmp-buffer")
  )