image-transform-properties
image-transform-properties is a compiled Lisp function in `image-mode.el
'.
(image-transform-properties SPEC)
Return rescaling/rotation properties for image SPEC.
These properties are determined by the Image mode variables
`image-transform-resize' and `image-transform-rotation'. The
return value is suitable for appending to an image spec.
Rescaling and rotation properties only take effect if Emacs is
compiled with ImageMagick support.