image-dired-display-image

image-dired-display-image is a compiled Lisp function in `image-dired.el'.

(image-dired-display-image FILE &optional ORIGINAL-SIZE)

Display image FILE in image buffer.
Use this when you want to display the image, semi sized, in a new
window. The image is sized to fit the display window (using a
temporary file, don't worry). Because of this, it will not be as
quick as opening it directly, but on most modern systems it
should feel snappy enough.

If optional argument ORIGINAL-SIZE is non-nil, display image in its
original size.