Gets the pixel values from an image.
The function image-access-transfer-from-image gets the pixel values from an image object, making them accessible via a corresponding Image Access object image-access .
image-access must be an Image Access object returned by make-image-access.
Notionally mage-access-transfer-from-image transfers the pixel data from the window system into image-access , though it might do nothing on platforms where the window system allows direct access to the pixel data.
The pixel data can be accessed using image-access-pixel.