Large images in comparison with VB6

13 Aug 2005 12:11 PM

Erik

Hi all,

Our software need to work with large bitmaps (approx. 3 to 6 megabytes). Our
previous versions were all build with VB6 and used the PictureBox control to
load, zoom and pan the bitmap. It all works without a problem, and it is
pretty fast. We are rebuilding our software in .Net and experiencing
performance problems when it comes to loading, displaying, panning and
zooming this large bitmaps. In other words: it is unacceptable slow. How
come that the same techniques works flawless in a prehistoric [ :-) ]
programminglanguage/environment and seem to fail completly in a modern one
like .Net?

I've already tried different approaches (like drawing directly on a graphics
surface etc.), but zooming and panning of a large images is realy slow.

Another thing is that those images consume lots more memory in .Net than it
did in VB6....

Am i missing something here? Should i use DirectX? I've googled my *ss of,
but i can't find 'the' solution.....

Hints, tips, URL..... anything is helpfull...

Greets,
Erik.

15 Aug 2005 12:43 PM

Cowboy (Gregory A. Beamer) - MVP

I would look at any open source gaming engines you can find in .NET. GDI+
sample apps are also nice. The reason is simple, both deal with graphics
rendering.

Larger? To be expected. Remember that COM and the VB Runtime are preloaded,
so you do not see the overhead footprint when you run a VB COM application.

Performance? Not sure. A C (or perhaps even COM) implementation that
directly contacts the APIs will be fastest. DirectX in C++ will also be very
fast. Neither has a managed environment, so there are trade offs. It is
possible VB COM will be faster. For .NET, the 2.0 framework will be faster
than 1.x.

--
Gregory A. Beamer
MVP; MCP: +I, SE, SD, DBA

***************************
Think Outside the Box!
***************************

Show quoteHide quote

"Erik" wrote:

> Hi all,
>
> Our software need to work with large bitmaps (approx. 3 to 6 megabytes). Our
> previous versions were all build with VB6 and used the PictureBox control to
> load, zoom and pan the bitmap. It all works without a problem, and it is
> pretty fast. We are rebuilding our software in .Net and experiencing
> performance problems when it comes to loading, displaying, panning and
> zooming this large bitmaps. In other words: it is unacceptable slow. How
> come that the same techniques works flawless in a prehistoric [ :-) ]
> programminglanguage/environment and seem to fail completly in a modern one
> like .Net?
>
> I've already tried different approaches (like drawing directly on a graphics
> surface etc.), but zooming and panning of a large images is realy slow.
>
> Another thing is that those images consume lots more memory in .Net than it
> did in VB6....
>
> Am i missing something here? Should i use DirectX? I've googled my *ss of,
> but i can't find 'the' solution.....
>
> Hints, tips, URL..... anything is helpfull...
>
> Greets,
> Erik.
>
>
>

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