How can I do it faster (Bitmap from IntPtr, EDSDK)

Question

Now I work on Canon EDSDK for myself. I get liveview image to very slow (5 image per second). How can I do it faster?.

This is my code for getting pointer to image:


    uint _err = EDSDK.EDS_ERR_OK;
    IntPtr imageRef = IntPtr.Zero;
    IntPtr streamRef = IntPtr.Zero;
    IntPtr streamPtr = IntPtr.Zero;
    uint Length = 0;

    _err = EDSDK.EdsCreateMemoryStream(0, out streamRef);
    if (EDSDK.EDS_ERR_OK == _err)
      _err = EDSDK.EdsCreateEvfImageRef(streamRef, out imageRef);

    if (EDSDK.EDS_ERR_OK == _err)
      _err = EDSDK.EdsDownloadEvfImage(_camera, imageRef);          

    if (EDSDK.EDS_ERR_OK == _err)
    {
      // display image
      _err = EDSDK.EdsGetPointer(streamRef, out streamPtr);
      if (EDSDK.EDS_ERR_OK == _err)
        _err = EDSDK.EdsGetLength(streamRef, out Length);
    }

then I load image to Bitmap and it's very very slow. My code:


    byte[] b = new byte[Length];
    Marshal.Copy(streamPtr, b, 0, (int)Length);
    using ( MemoryStream ac = new MemoryStream(b))
    {
      img = (Bitmap)Image.FromStream(ac);
      ac.Close();
    }

HEEEELP PLEASE!!! Very slow code is decoding JPEG. How to make it faster? — user1920116, Jan 23 '13 at 17:11

score 1 · Answer 1 · answered Feb 21 '13 at 20:13

1

libjpeg-turbo, available here http://libjpeg-turbo.virtualgl.org/ will decode in real-time

answered Feb 21 '13 at 20:13

rossb83

1,694
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score 0 · Answer 2 · edited Nov 03 '13 at 16:51

0

Have you tried using the EdsGetImage method to extract the image data from the memory stream?

In order to use this method you will need to create an additional Image Reference from the memory stream after you use the EdsDownloadEvf method (using the EdsCreateImageRef method). You may then use this Image Reference in the EdsGetImage method to extract the uncompressed Image Data.

edited Nov 03 '13 at 16:51

Josh Crozier

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answered Jan 31 '13 at 10:08

Avinash

23
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EdsGetImage return Invalid Parameter for EvfImageRef – user1920116 Feb 09 '13 at 09:56

How can I do it faster (Bitmap from IntPtr, EDSDK)

2 Answers2