[Vxl-users] From generic buffer to vil_image_view

[Junaed S. <ju...@ci...>]

Hi there,
I have a question about accessing image data stored in byte buffers 
through vil_image_view objects. For example, lets say I have a firewire 
camera that takes a 1024-by-768 RGB color frame and stores it into a 
byte  (unsigned char) buffer called capturebuffer. I have another object 
called vxlimage, and I want this object to point to the data stored in 
capturebuffer. I plan on doing something like this:

vxlimage.set_to_memory( (const vxl_byte *)capturebuffer, 0, 0, 3, _, _, _ );

The last three arguments are where I am confused. I got this from the 
package documentation:

---------------------
template<class T>
void vil_image_view 
<http://paine.wiau.man.ac.uk/pub/doc_vxl/core/vil/html/classvil__image__view.html>< 
T >::set_to_memory 	(  	const T *  	/top_left/,

	
	unsigned  	/ni/,

	
	unsigned  	/nj/,

	
	unsigned  	/nplanes/,

	
	vcl_ptrdiff_t  	/i_step/,

	
	vcl_ptrdiff_t  	/j_step/,

	
	vcl_ptrdiff_t  	/plane_step/

	)  	

Set this view to look at someone else's memory data.

If the data goes out of scope then this view could be invalid, and 
there's no way of knowing until it's too late -- so take care!

Note that though top_left is passed in as const, the data may be 
manipulated through the view.

---------------------
Could someone explain to me the last three args a bit more? Or point me 
to some resource that might be helpful?

Thanks a bunch!

-J-