Hello Andrew, thank you for your reply. I already use the Lockbits-method and it gave a good performance boost once I implemented it weeks ago. But the performance is still not good enough. I decided to just use C# and no C, but maybe thats the only possibilty to make it faster now. One big problem is that a brightness change should work in realtime, the user should see the change immediately. I tried it with indexed bitmaps and a Change of the Palette of this bitmap, which works wonderful but is still a litle slow. For that reason I wanted to decrease the size of the bitmap before changing the brightness. For that reason I used the Bitmap-Constructor which requires a Bitmap and the Width and Height of the new Bitmap as paramters: public Bitmap ( System.Drawing.Image original , System.Int32 width , System.Int32 height) But the bitmap this constructor delivers doe not have a Palette. :sigh: So I cannot change the Brightness by changing the palette. :confused: Anyone has experience with that? :confused: :confused:

I'm working on an application in C#, which has the capabilities of displaying and processing images. (one at a time, the images are rather large but I finally decided on resizing them to moderate sizes (e.g. 600*600)) ;) There's not much image processing involved but zoom, mirroring, rotation and brightness change should be possible. The most important fact is performance. The image should be displayed very fast and the image processing steps sould be very fast too. I'm trying to brainstorm some new ideas of doing the displaying and image processing because I tried so many things but I'm not satisfied with the results. I tried it with GDI+ (with and without brushes) and with Managed DirectX (Direct3D and also DirectDraw). Anyone here has good ideas of doing it? Am I on the right path or did I miss a possibility? :confused: Right now I tend to do it with GDI+ because DirectX does not really work faster and is more complicated to use. :) thank you very much. -- modified at 10:22 Tuesday 30th August, 2005

I'm displaying a bitmap Image with DirectDraw. Now I want to change the Brightness of the image. I thought it could work by changing the Palette. The problem is that I am not able to add a palette to a surface. I tried to add it with the constructor for the Palette which needs a Surface as argument. Is it possible to change the pixelFormat of the Surface. If O could set in to 8bppIndexed then I would also have a palette, right? I think it is very hard to work with Direct Draw because the DirectDraw documentation in ManagedDirectX 9.0 is very bad.:(( Can anyone help? :) Thank you very much -- modified at 9:05 Wednesday 31st August, 2005

Hi Daniel, sorry, I've been on vacation for a while. No, my monitor/ graphics card won't display the whole Image, that's why i started to think about resizing it to a moderate size. Do you know, how I can do it in Direct Draw? I'm right now trying to figure out how fast it would be with Direct Draw (Managed DirectX 9.0).

Thanks again, Daniel. I made BitBlt work but it is not much faster than the old version with DrawImage(). Are there any other ideas? Thanks for your help. SILKA

The Idea sounds good. I would give it a try. I searched a little bit in the web and the MSDN. How do I use BitBlt in C#. Did you use it in a c#-application and could you give me some code snippets? Thanks a lot for your help.:) Silka

ANYONE GOOD IDEAS? I want to display Bitmaps with DirectX. I need a good performance, for that reason I'm not using GDI+. I load the Bitmaps into a Texture and draw them on Screen using the DrawPrimitives()-Method. It works fine for small Bitmaps. But I need to display large Bitmaps (e.g. 5000x4000 Pixels), which cannot be directy loaded in ONE Texture. My graphics card supports textures up to 4096X4096 Pixels, which is even not enough :sigh: And most of the common graphics cards don't support textures this size, right? How can I split one Bitmap in different Textures so that I can display these Bitmaps? That was my idea, but I don't know how to do it. :(( Or does anyone have another idea of displaying Bitmaps this size? :confused: I would be very greatful if anyone can help me! :) Silka