On retrieving bits from a device context

I have two bitmaps which are selected into memory device context's

I do an Alpha Blend:

AlphaBlend(dcComparisonMem, 0,0, m_Width, m_Height, dcImageMem, 0,0,m_Width, m_Height,m_bf);

I need to now pull the bits out of dcComparisonMem into a buffer:

BYTE* pData = new BYTE(3000000)

for further processing post alpha-blend (rather than immediately blitting it to the display)

I thought I had to  do something like this:

VOID *pbitsBW;      
HBITMAP hBlended = ::CreateDIBSection(dcComparisonMem, pbmInfo, DIB_RGB_COLORS, &pbitsBW, NULL, NULL);
int iGetCount = ::GetDIBits(dcComparisonMem, hBlended, 0, m_Height, pData, pbmInfo, DIB_RGB_COLORS);

but iGetCount is only then equal to 1000 and my pData buffer doesn't hold the right data.

How do I retrived the bits into pData out of the DC  to which the AlphaBlend method blended the two?


Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

If memory bitmap is created using CreateDIBSection, use GetBitmapBits to extract bits from it.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
System Programming

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.