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Ok, I'm not the most experience C++ programmer, so promise not to laugh! There are no C++ examples in the docs, so how does one get started? I've created a project, inserted a FileDialog ActiveX control and a Bitmapviewer ActiveX control - but how do I create a Bitmap object? Shouldn't there be a .tlh file or something like that? Or shouldn't I have to run CoInitialize on the DLL? Any help from anyone who as done this would be greatly appreciated. Thanks, Ken
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You should create wrappers from the Graphics Mill type library. To do it use #import directive (if you are using Visual Studio). You can read about it more detailed in MSDN: http://msdn.microsoft.com/library/en-us/vclang/html/_predir_The_.23.import_Directive.asp As for CoInitialize, it depends on the project type you use. If you create MFC project with ActiveX components usage, it is generated by wizard. I have attached sample MFC project (requires Visual Studio 2003 .NET). Hope it helps. |
Best regards, Fedor Skvortsov |
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Thanks, things are moving along for me, but now I have another problem. I have added the following lines to the OnBnClickedBrightcontrast() method to convert to black and white: Code:CComPtr<IBitmapData> piBitmapData;
hr = piBitmap->get_Data(&piBitmapData);
if (FAILED(hr))
DisplayErrorMessage(hr);
CComPtr<IBitmap> piTempBitmap;
piTempBitmap = NULL;
hr = piBitmapData->ConvertTo1bppIndexedDitheringTypeOrdered ,1,OrderedDitheringTypeSpiral,2,&piTempBitmap);
if (FAILED(hr))
DisplayErrorMessage(hr);
This works (eg it looks good on the screen), but when I save the file, the program dies (the file is successfully saved, but the SaveToFile method does not return). The error is "unhandled exception". As an experiment I tried using the ConvertTo16bppAlphaGrayscale method and this works fine. It looks like a file format conversion error going from color to b&w, but happening in the SaveToFile method. Thanks, Ken Edited by user Monday, December 24, 2007 4:17:05 PM(UTC)
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Did you modify the code which saves the image to the file? Could you post it? Also, what file format are you saving to?
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By the way, if you do not use ApplyInPlace property, there is no need to use piTempBitmap variable. You can just specify NULL instead: Code:hr = piBitmapData->ConvertTo1bppIndexed(DitheringTypeOrdered, 100,OrderedDitheringTypeSpiral,2,NULL);
Edited by user Monday, December 24, 2007 4:17:24 PM(UTC)
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Here is the entire procedure that I changed. Note that I did not change the Save procedure, just added the conversion to b&w. I am trying to save to .bmp file, either 1 bit or 8 bits. Note that if I convert to 1 bit and then to 8 bits grayscale the (per the example below, see comments) then it works fine! Probably something to do with saving a 1 bit deep bitmap. thanks, ken Code:void CGraphicsMillCppSampleDlg::OnBnClickedBrightnesscontrastbutton()
{
// Get access to the BitmapViewer control and retrieve an IBitmap, associated with
// this control.
CComQIPtr<IBitmapViewer, &IID_IBitmapViewer> piBitmapViewer;
piBitmapViewer = GetDlgItem(IDC_BITMAPVIEWER)->GetControlUnknown();
CComPtr<IBitmap> piBitmap;
HRESULT hr = piBitmapViewer->get_Bitmap(&piBitmap);
if (FAILED(hr))
return DisplayErrorMessage(hr);
// Create a brightness/contrast dialog. To be able to show a preview,
// we pass the bitmap into this dialog.
CBrightnessContrastDialog brightnessDlg;
brightnessDlg.InitPreview(piBitmap);
// Open the dialog and if necessary, apply brightness/contrast adjustment.
INT_PTR res = brightnessDlg.DoModal();
if (res == IDOK)
{
// To change brightness/contrast, we should get IColorAdjustment interface
// and call BrightnessContrast method.
CComPtr<IColorAdjustment> piColorAdjustment;
hr = piBitmap->get_ColorAdjustment(&piColorAdjustment);
if (FAILED(hr))
DisplayErrorMessage(hr);
// Get brightness and contrast modifiers from the control.
hr = piColorAdjustment->BrightnessContrast(brightnessDlg.GetBrightnessAmount(), brightnessDlg.GetContrastAmount(), NULL);
if (FAILED(hr))
DisplayErrorMessage(hr);
// arbitrarily reduce it to 1 bit (in this case no dithering)
CComPtr<IBitmap> piBitmap;
hr = piBitmapViewer->get_Bitmap(&piBitmap);
CComPtr<IBitmapData> piBitmapData;
hr = piBitmap->get_Data(&piBitmapData);
if (FAILED(hr))
DisplayErrorMessage(hr);
CComPtr<IBitmap> piTempBitmap;
piTempBitmap = NULL;
// The following line causes the SaveToFile operation to cause an exception, but the Save is actually done
hr = piBitmapData->ConvertTo1bppIndexed(DitheringTypeNone,1,OrderedDitheringTypeSpiral,2,&piTempBitmap);
if (FAILED(hr))
DisplayErrorMessage(hr);
// NOTE: if you uncomment the following lines and convert to 8 bit grayscale it works fine!
//hr = piBitmapData->ConvertTo8bppGrayscale(0,0,&piTempBitmap);
//if (FAILED(hr))
// DisplayErrorMessage(hr);
}
}
Edited by user Monday, December 24, 2007 4:17:43 PM(UTC)
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Hi Ken, I still cannot reproduce the problem. Could you submit case with the image you are testing? Edited by user Friday, May 23, 2008 3:41:44 PM(UTC)
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Please forgive another beginner's question. Right now I am doing everything with pointers, like this: Code:CComPtr<IBitmap> piBitmap;
hr = piBitmapViewer->get_Bitmap(&piBitmap);
I would like to do things as follows (per an example you provided elsewhere): Code:GraphicsMill.BitmapClass bmp = new GraphicsMill.BitmapClass();
bmp.LoadFromFile(@"d:\[test files]\pictures\andrew.jpg");
But I don't have a clue about how to get started. How do I initialize things and make these classes known? Sorry for the very basic question. Yours, Ken Edited by user Monday, December 24, 2007 4:18:24 PM(UTC)
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Hi Ken, I think you should read more about ATL smart pointer concepts in MSDN... To create a coclass which implements some interface, the CComPtr class implements CoCreateInstance method. The code should be looking like this: Code:CComPtr<IBitmap> piBitmap;
HRESULT hr = piBitmap.CoCreateInstance(CLSID_Bitmap);
if (FAILED(hr))
{
// ... most likely means that GraphicsMill20.dll is not registered.
}
hr = piBitmap->LoadFromFile(CComBSTR(_T("d:\\test.jpg")));
// ...
In fact this mehtod wraps the CoCreateInstance Win32API function, which is also can be used (but the class method is more convenient). Edited by user Monday, December 24, 2007 4:18:36 PM(UTC)
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No, the smart pointers are working just fine, this works: Code:CComPtr<IBitmap> piBitmap;
HRESULT hr = piBitmap.CoCreateInstance(CLSID_Bitmap);
if (FAILED(hr))
{
// ... most likely means that GraphicsMill20.dll is not registered.
}
hr = piBitmap->LoadFromFile(CComBSTR(_T("d:\\test.jpg")));
But I like the idea of coding like this, per other examples on your website, so I was wondering how to do it: Code:GraphicsMill.BitmapClass bmp = new GraphicsMill.BitmapClass();
bmp.LoadFromFile(@"d:\[test files]\pictures\andrew.jpg");
It appears you are working with the structures themselves, not pointers. This makes it earier to get to, say, the bitmapdata structure. Thanks, Ken Edited by user Monday, December 24, 2007 4:19:00 PM(UTC)
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This code sample is not written on C++, but on C#... :) So this syntax cannot be used in C++.
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Ah, sorry for the misunderstanding. Ken
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