Re: [boost] [GIL] Loading a PNG from a stream

From: Michael Marcin (mike_at_[hidden])
Date: 2007-05-14 00:16:13

Stefan Seefeld wrote:
> Michael Marcin wrote:
>> Hello,
>>
>> I have the need to load a PNG from a generic input stream that has a similar 
>> interface (i.e. has a read, operator ! and fail with the same 
>> signature/semantics as std::istream).  The png reading extensions don't 
>> appear to be able to load from anything other than a FILE*.  In a library as 
>> modern as GIL I'm sort of suprised there is apparently no way to load from a 
>> generic stream.
> 
> Indeed, I agree. (And I remember mentioning in the review that I found the FILE
> API to be inappropriate for a boost C++ API.)
> 
>> Anyone have an idea how to make this happen?  Perhaps there is another PNG 
>> library written in C++ or a wrapper around the C libpng?
> 
> I did write iostream adapters for libpng, and would happily contribute it
> to boost.GIL if there is interest.
> 

I'm interested... could you perhaps put it in the vault?
Is it still efficient for loading PNGs?  Does it require the stream to 
backtrack?

Thanks,

Michael Marcin