Im refferring to this OpenCV function on this post

IplImage* cvLoadImage(const char* filename, int iscolor=CV_LOAD_IMAGE_COLOR )

I'm tring to get the c functionality where i can access the imageData struct member of IplImage with the below statement (more info here http://docs.opencv.org/modules/core/doc/old_basic_structures.html?highlight=pli#iplimage)

IplImage* converted_image= cvLoadImage("c:\\box_in_scene.png",0):converted_image->imageData

when i try with this

(dp converted-image (Load-image "/home/w/Documents/opencv-
2.4.6.1/samples/c/box_in_scene.png" 0))

(cffi:with-foreign-slots ((image-data)
converted-image (:struct ipl-image))
(cffi:foreign-string-to-lisp image-data))

I get the post title error message.  I also get message when i try to setf IMAGE-DATA to another variable or list it .....i get same thing with foreign-slot-value
here is sampling of the more than 6 pages of converted_image->imageData that was cout'ed in C 

P1']}stqouqwruM/./22330/00+1)/+%+8S~sx{zzx|x~|x~y{~Y(&&''()+,%(%$%!  $l~