How to convert CBitmap to DIB and backwards

[uus99]

I have a 32 bit (RGBA) image in CBitmap, and for processing purposes i get the array using GetBitmapBits & SetBitmapBits. And after that plot to screen. The problem is that is only works if the target system is also running on 32bit screen depth. How can i get an array of pixel values from CBitmap to a DIB then after processing plot to screen? Also, any DIB class? I'm completely lost.

[Chris Losinger]

uus99 wrote: The problem is that is only works if the target system is also running on 32bit screen depth why doesn't it work on other bit depths? what happens? Cleek | Losinger Designs | ClickPic | ThumbNailer

[John R Shaw]

RGBA: sounds like you are using GDI+. In which case look up GDI+ here at CP, there are several aticles on working with bitmaps. Also, check out Bitmaps & Palettes: CxImage, CDIBSection, CDibData uses GDI and sould give you an insight on converting from one format to anouther if needed. Using GetBitampBits and SetBitmapBits is not garanteed to give you the bits in any given format; therefore, they could eventualy return/set bits using a different format (driver dependent). Well I hope this helps. Good Luck! INTP

[uus99]

The thing is i am receiving an image from a frame grabber in MemDC, which the image is RGBA (32bits) and tha A=0 all the times, so actually it is RGB (24bits+8bits empty). At the moment, i can plot to screen using pDC->StretchBlt(20,40,180,180,&MemDC,10,40,512,512,SRCCOPY); It works, coz my screen is on 32bit depth. If my screen is changed to 24bit or 16bit, nothing comes out. So, how can i make sure that i can always plot to any screen depth? I should use DIB is it?

[John R Shaw]

Sorry I have be gone for a few days. It almost sounds like the MemDC and the pDC are incompatible, because the color depth of the bitmap should not be the problem. If you select a bitmap of higher resolution than the screen and then blit it to the screen all you should notice, if any thing, is that the colors appear wrong. The only reason (normaly) for using a DIB, insted of a the normal windows bitmap type, is when you need to access the bits directly (more efficeintly). I do no beleive using a DIB will fix the problem. If you do not have a copy of Programming Windows by Charles Petzold, then I recommend you get one, it provides good information on GDI as well as code for working with DIBs. The bit manipulation code in CDibData was based mosly on information from that book. Good Luck! P.S. if you figure out what the problem is, please post it. INTP