[plt-scheme] Image library bug?

On Dec 7, 2009, at 4:37 PM, Robby Findler wrote:
>> I see there isn't
>> an equivalent of the image<->color-list functions in the new  
>> library; is
>> that likely to make its way in eventually?  If not, it would be  
>> nice to have
>> a way to make this work in the old version.
>
> Yes, there will be something along these lines in 2htdp/image
> eventually. But it won't be quite the same; specifically you'll only
> be able to get back a bitmap not an image.

This makes sense.

>> If there are plans to support color structs in the 2e
>> version, it'd be Really Neat if both kinds could work, or if alpha- 
>> colors
>> were the only kind of color struct (perhaps with a constructor like
>> make-color that creates a fully-opaque color).
>
> I'd like to add something like slideshow's cellophane operator
> instead, probably. Would that work okay for you?

Yes, that seems reasonable.  I saw the "stamp" and "see-thru"  
operators in the source of private/image-more.ss -- are those the ones  
you're planning on?  That sounds good, if so...and incidentally, one  
of my students asked a question amounting to whether we can get the  
union, intersection, or difference of two images of shapes, and for  
his immediate purpose I think those two operators would have sufficed.

Thanks again,
jmj