WinRT C++ (Win10)、opencv HSV 颜色 space、图像显示、伪像

Question

我的目标是进行对象跟踪。

我有一个 UWP c# 应用程序和链接的 c++ windows 运行时组件。在那里我可以获得对 opencv 的访问权限。

在 c# 中，MediaCapture return SoftwareBitmap。
然后我把SoftwareBitmap传给c++，转成opencv的Mat。
然后cvtColor(cvFrame, cvFrame, COLOR_BGR2HSV);
然后转换回 SoftwareBitmap，使用 BitmapPixelFormat::Bgra8（只有 Bgra8 被 Software Bitmap 接受）和 BitmapAlphaMode::Ignore

这就是我所拥有的 screen

如果我跳过 cvtColor 部分并仅转换为 cv::Mat 并返回到 SoftwareBitmap，结果我得到了一个漂亮的图像...

我知道图像的通道有问题……但我不知道该去哪里挖掘。我假设 cvtColor 之后的 cv::Mat 是正确的......但我想查看图片创建的中间步骤。（HSV、阈值，然后是结果）

如有任何建议，我们将不胜感激。

PS 我试过 imwrite 但没有创建文件。

更新转换 from/to

Mat Convert(SoftwareBitmap^ from)
{
    BitmapBuffer^ bmpBuffer = from->LockBuffer(BitmapBufferAccessMode::ReadWrite);

    unsigned char* pPixels = GetPointerToPixelData(bmpBuffer->CreateReference());

    Mat mat(from->PixelHeight, from->PixelWidth, CV_8UC4);
    memcpy(mat.data, pPixels, 4 * from->PixelHeight * from->PixelWidth);

    return mat;
}

SoftwareBitmap^ Convert(Mat from)
{
    SoftwareBitmap^ sBitmap = ref new SoftwareBitmap(BitmapPixelFormat::Bgra8, from.cols, from.rows, BitmapAlphaMode::Ignore);
    BitmapBuffer^ bmpBuffer = sBitmap->LockBuffer(BitmapBufferAccessMode::ReadWrite);
    auto reference = bmpBuffer->CreateReference();

    unsigned char* dstPixels = GetPointerToPixelData(reference);
    memcpy(dstPixels, from.data, from.step.buf[1] * from.cols*from.rows);

    return sBitmap;
}

unsigned char* GetPointerToPixelData(IBuffer^ buffer)
{
    ComPtr<IBufferByteAccess> bufferByteAccess;
    ComPtr<IInspectable> insp((IInspectable*)buffer);
    ThrowIfFailed(insp.As(&bufferByteAccess));

    unsigned char* pixels = nullptr;
    ThrowIfFailed(bufferByteAccess->Buffer(&pixels));

    return pixels;
}

unsigned char* GetPointerToPixelData(IMemoryBufferReference^ reference)
{
    ComPtr<IMemoryBufferByteAccess> bufferByteAccess;

    ThrowIfFailed(reinterpret_cast<IInspectable*>(reference)->QueryInterface(IID_PPV_ARGS(&bufferByteAccess)));

    unsigned char* pixels = nullptr;
    unsigned int capacity = 0;
    ThrowIfFailed(bufferByteAccess->GetBuffer(&pixels, &capacity));

    return pixels;
}

Answer 1

因为您没有 post 执行实际转换的代码 from/to SoftwareBitmap/cv::Mat.

我最好的猜测是 3 通道图像数据显示时好像有 4 通道。

Answer 2

好的，我找到了解决方案。

//convert from SoftwareBitmap to Mat
Mat cvFrame = this->Convert(frame);

//change color space
cvtColor(cvFrame, cvFrame, COLOR_BGR2HSV);

// split chanels
vector<Mat> hsvChannels(3);
split(cvFrame, hsvChannels);

//create empty chanel
Mat empty;
empty = Mat::zeros(cvFrame.rows, cvFrame.cols, CV_8UC1);

// create hsv with empty alpha
vector<Mat> channels;
channels.push_back(hsvChannels[0]); //h
channels.push_back(hsvChannels[1]); //s
channels.push_back(hsvChannels[2]); //v
channels.push_back(empty); //a

//put back to Mat
merge(channels, cvFrame);

// convert back to SoftwareBitmap 
return this->Convert(cvFrame);

WinRT C++ (Win10)、opencv HSV 颜色 space、图像显示、伪像

WinRT C++ (Win10), opencv HSV color space, image display, artifacts

c#

opencv

windows-runtime

c++-cx

opencv3.0