IWICBitmapDecoderInfo interface

    IWICImagingFactory *pFactory = NULL;
    IWICStream *pStream = NULL;
    IEnumUnknown *pEnumerator = NULL;
    IWICBitmapDecoder *pDecoder = NULL;

    HRESULT hr = CoCreateInstance(
                    CLSID_WICImagingFactory, 
                    NULL,
                    CLSCTX_INPROC_SERVER,
                    IID_IWICImagingFactory,
                    (LPVOID*) &pFactory);

    if (SUCCEEDED(hr))
    {
        hr = pFactory->CreateStream(&pStream);
    }

    if (SUCCEEDED(hr))
    {
        hr = pStream->InitializeFromFilename(L"test.jpg", GENERIC_READ);
    }

    if (SUCCEEDED(hr))
    {
        hr = pFactory->CreateComponentEnumerator(
                           WICDecoder,
                           WICComponentEnumerateDefault,
                           &pEnumerator);
    }

    if (SUCCEEDED(hr))
    {
        IUnknown *pUnknown = NULL;
        IWICBitmapDecoderInfo *pDecoderInfo = NULL;
        ULONG actual = 0;
        ULONG ulHighestWeight = 0;
        CLSID clsid = { 0 };

        while (SUCCEEDED(hr) && SUCCEEDED(pEnumerator->Next(1, &pUnknown, &actual)) && (actual > 0))
        {
            BOOL fPatternMatch = FALSE;

            hr = pUnknown->QueryInterface(
                               IID_IWICBitmapDecoderInfo,
                               reinterpret_cast<void**>(&pDecoderInfo));
            pUnknown->Release();
            pUnknown = NULL;

            if (SUCCEEDED(hr))
            {
                hr = pDecoderInfo->MatchesPattern(pStream, &fPatternMatch);
            }

            if (SUCCEEDED(hr) && fPatternMatch)
            {
                hr = pDecoderInfo->CreateInstance(&pDecoder);

                if (SUCCEEDED(hr))
                {
                    ULONG ulWeight = 0;
                    DWORD capabilities;
                    hr = pDecoder->QueryCapability(pStream, &capabilities);

                    if (SUCCEEDED(hr))
                    {
                        // We're going to weight a decoder whose encoder created the file the highest,
                        // followed (from higher to lower importance) by decoders that can extract an image,
                        // thumbnail, and metadata. Keep in mind that an app can use a different heuristic
                        // here, depending on the type of information that it needs from the decoder. If it
                        // only needs metadata, it can simply grab the first decoder that can parse metadata.
                        ulWeight = ((capabilities & WICBitmapDecoderCapabilitySameEncoder)          != 0) * 5 +
                                   ((capabilities & WICBitmapDecoderCapabilityCanDecodeAllImages)   != 0) * 4 +
                                   ((capabilities & WICBitmapDecoderCapabilityCanDecodeSomeImages)  != 0) * 3 +
                                   ((capabilities & WICBitmapDecoderCapabilityCanDecodeThumbnail)   != 0) * 2 +
                                   ((capabilities & WICBitmapDecoderCapabilityCanEnumerateMetadata) != 0);

                        if (ulWeight > ulHighestWeight)
                        {
                            hr = pDecoderInfo->GetCLSID(&clsid);

                            if (SUCCEEDED(hr))
                            {
                                ulHighestWeight = ulWeight;
                            }
                        }
                    }

                    pDecoder->Release();
                    pDecoder = NULL;
                }
            }

            pDecoderInfo->Release();
            pDecoderInfo = NULL;
        }

        pEnumerator->Release();
        pEnumerator = NULL;
    }

    if (pStream)
    {
        pStream->Release();
    }

    if (pFactory)
    {
        pFactory->Release();
    }

    return hr;