Some WIC Bitmap tests

wicbitmaptests.cpp

#include <windows.h>
#include <atlbase.h>
#include <stdio.h>
#include <wincodec.h>

#define HRASSERT(x) ATLASSERT(SUCCEEDED(x))

HRESULT ConvertBitmapTo256(PCWSTR input, PCWSTR output, REFGUID outputFormat)
{
	HRESULT hr = S_OK;
	CComPtr<IWICImagingFactory> fac;
	HRASSERT(fac.CoCreateInstance(CLSID_WICImagingFactory));

	// or use fac->CreateBitmapFromHBITMAP(...) to start from HBITMAP
	CComPtr<IWICBitmapDecoder> decoder;
	HRASSERT(fac->CreateDecoderFromFilename(input, nullptr, GENERIC_READ, WICDecodeOptions::WICDecodeMetadataCacheOnDemand, &decoder));

	// create a converter
	CComPtr<IWICFormatConverter> converter;
	HRASSERT(fac->CreateFormatConverter(&converter));

	// get first frame (bmp only have one)
	CComPtr<IWICBitmapFrameDecode> frame;
	HRASSERT(decoder->GetFrame(0, &frame));

	// you can use your custom palette too (4th parameter)
	HRASSERT(converter->Initialize(frame, GUID_WICPixelFormat8bppIndexed, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone216));

	// you can do B&W too, note not all combination of dithering & palette work, these works
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeErrorDiffusion, nullptr, 0, WICBitmapPaletteTypeFixedBW);
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone216);

	// save back, create encoder
	CComPtr<IWICBitmapEncoder> encoder;
	HRASSERT(fac->CreateEncoder(outputFormat, nullptr, &encoder));

	// create output stream, here a file stream, but any stream can do (SHCreateMemStream for mem stream)
	CComPtr<IStream> stream;
	SHCreateStreamOnFile(output, STGM_WRITE | STGM_SHARE_EXCLUSIVE | STGM_CREATE, &stream);
	HRASSERT(encoder->Initialize(stream, WICBitmapEncoderNoCache));

	// create new frame, write and commit
	CComPtr<IWICBitmapFrameEncode> frameEncode;
	HRASSERT(encoder->CreateNewFrame(&frameEncode, nullptr));
	HRASSERT(frameEncode->Initialize(nullptr));
	HRASSERT(frameEncode->WriteSource(converter, nullptr));
	HRASSERT(frameEncode->Commit());
	HRASSERT(encoder->Commit());
	return hr;
}

HRESULT ConvertHBITMAPTo256(HBITMAP input, PCWSTR output, REFGUID outputFormat)
{
	HRESULT hr = S_OK;
	CComPtr<IWICImagingFactory> fac;
	HRASSERT(fac.CoCreateInstance(CLSID_WICImagingFactory));

	CComPtr<IWICBitmap> bitmap;
	HRASSERT(fac->CreateBitmapFromHBITMAP(input, nullptr, WICBitmapUseAlpha, &bitmap));

	// create a converter
	CComPtr<IWICFormatConverter> converter;
	HRASSERT(fac->CreateFormatConverter(&converter));

	// you can use your custom palette too (4th parameter)
	HRASSERT(converter->Initialize(bitmap, GUID_WICPixelFormat8bppIndexed, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone216));

	// you can do B&W output too, note not all combination of dithering & palette work, these works
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeErrorDiffusion, nullptr, 0, WICBitmapPaletteTypeFixedBW);
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone216);

	// save back, create encoder
	CComPtr<IWICBitmapEncoder> encoder;
	HRASSERT(fac->CreateEncoder(outputFormat, nullptr, &encoder));

	// create output stream, here a file stream, but any stream can do (SHCreateMemStream for mem stream)
	CComPtr<IStream> stream;
	SHCreateStreamOnFile(output, STGM_WRITE | STGM_SHARE_EXCLUSIVE | STGM_CREATE, &stream);
	HRASSERT(encoder->Initialize(stream, WICBitmapEncoderNoCache));

	// create new frame, write and commit
	CComPtr<IWICBitmapFrameEncode> frameEncode;
	HRASSERT(encoder->CreateNewFrame(&frameEncode, nullptr));
	HRASSERT(frameEncode->Initialize(nullptr));
	HRASSERT(frameEncode->WriteSource(converter, nullptr));
	HRASSERT(frameEncode->Commit());
	HRASSERT(encoder->Commit());
	return hr;
}

// *warning* not sure this one works!
HRESULT ConvertHBITMAPTo256(HBITMAP input, HBITMAP* output, HPALETTE *palette)
{
	HRESULT hr = S_OK;
	CComPtr<IWICImagingFactory> fac;
	HRASSERT(fac.CoCreateInstance(CLSID_WICImagingFactory));

	CComPtr<IWICBitmap> bitmap;
	HRASSERT(fac->CreateBitmapFromHBITMAP(input, nullptr, WICBitmapUseAlpha, &bitmap));

	// create a converter
	CComPtr<IWICFormatConverter> converter;
	HRASSERT(fac->CreateFormatConverter(&converter));

	// here we use 256 color format with predefined palette, but one can use a custom palette too (4th parameter)
	HRASSERT(converter->Initialize(bitmap, GUID_WICPixelFormat8bppIndexed, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone256));

	// one can do B&W output too, note not all combination of dithering & palette work, these works
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeErrorDiffusion, nullptr, 0, WICBitmapPaletteTypeFixedBW);
	//converter->Initialize(frame, GUID_WICPixelFormatBlackWhite, WICBitmapDitherTypeOrdered16x16, nullptr, 0, WICBitmapPaletteTypeFixedHalftone216);

	// save back, create encoder
	CComPtr<IWICBitmapEncoder> encoder;
	HRASSERT(fac->CreateEncoder(GUID_ContainerFormatBmp, nullptr, &encoder));

	// create output stream in memory
	CComPtr<IStream> stream;
	HRASSERT(CreateStreamOnHGlobal(nullptr, TRUE, &stream));
	HRASSERT(encoder->Initialize(stream, WICBitmapEncoderNoCache));

	// create new frame, write and commit
	CComPtr<IWICBitmapFrameEncode> frame;
	HRASSERT(encoder->CreateNewFrame(&frame, nullptr));
	HRASSERT(frame->Initialize(nullptr));
	HRASSERT(frame->WriteSource(converter, nullptr));
	HRASSERT(frame->Commit());
	HRASSERT(encoder->Commit());

	HGLOBAL h;
	HRASSERT(GetHGlobalFromStream(stream, &h));

	auto file = (BITMAPFILEHEADER*)GlobalLock(h);
	auto info = (BITMAPINFOHEADER*)((LPBYTE)file + sizeof(BITMAPFILEHEADER));

	auto bits = (LPBYTE)file + file->bfOffBits;
	*output = CreateBitmap(info->biWidth, info->biHeight, info->biPlanes, info->biBitCount, bits);
	if (*output)
	{
		// bit of a hack, we write the memory file so we don't have to allocate for the palette
		// but we won't need it anymore
		auto lp = (LOGPALETTE*)&info->biClrImportant;
		lp->palNumEntries = info->biClrUsed;
		lp->palVersion = 0x300;
		*palette = CreatePalette(lp);
		if (!*palette)
		{
			hr = E_FAIL;
			DeleteObject(*output);
		}
	}
	else
	{
		hr = E_FAIL;
	}
	GlobalUnlock(h);
	return hr;
}