Pass bitmap from C# to C++

Question

How can I pass a Bitmap object which is loaded from C# to C++ native code, actually I'm working on wrapping some OpenCV API to be used from C# But I faced a problem in passing the bitmap from c# and reconstruct it on c++

any code or idea would be appreciated

This has been asked and answered before: http://stackoverflow.com/questions/661016/how-can-i-pass-a-net-bitmap-to-a-native-dll?rq=1 — Security Hound, Nov 28 '12 at 12:49

score 1 · Answer 1 · edited Jan 11 '21 at 20:50

1

You can use the LockBits method to lock the Bitmap pixels in memory, and pass the pointer to the first pixel, the dimensions and the stride to C++ using a P/Invoke call.

Overview of LockBits: https://web.archive.org/web/20141229164101/http://bobpowell.net/lockingbits.aspx

After the native code has finished processing the image, you would then free the lock using UnlockBits.

edited Jan 11 '21 at 20:50

Andrew Morton

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answered Nov 28 '12 at 12:28

Rotem

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But passing the Scan0 to c++ will pass the point to the bits of the picture without the plate of the color – Niklaus Wirth Nov 28 '12 at 12:31

score 0 · Answer 2 · answered Nov 28 '12 at 12:30

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If you have a .NET Bitmap object you can use the function GetHBitmap() to get a pointer to the image acessible from unmanaged code.

answered Nov 28 '12 at 12:30

mortb

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score 0 · Answer 3 · answered Jan 17 '14 at 09:29

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Instead of implementing your own wrapper, you can use EmguCV.

answered Jan 17 '14 at 09:29

phyrox

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Pass bitmap from C# to C++

3 Answers3