使用像素数组初始化BitmapSource
本文关键字:初始化 BitmapSource 数组 像素数 像素 | 更新日期: 2023-09-27 18:26:47
我正在尝试将本机图像数据结构封送至BitmapSource。
这是本机结构:
struct Bitmap_8Bit
{
public:
unsigned char* data;
int stride;
int rows;
int cols;
int nChannels; //either 1 or 3. in case of three the order of the channels is BGR
};
这是我的编组功能:
template<>
inline
System::Windows::Media::Imaging::BitmapSource^ marshal_as<System::Windows::Media::Imaging::BitmapSource^, Bitmap_8Bit>(const Bitmap_8Bit& nativeBitmap)
{
System::Windows::Media::PixelFormat format = System::Windows::Media::PixelFormats::Default;
System::Windows::Media::Imaging::BitmapPalette^ palette = nullptr;
if (nativeBitmap.nChannels == 1)
{
format = System::Windows::Media::PixelFormats::Gray8;
palette = System::Windows::Media::Imaging::BitmapPalettes::Gray256;
}
else if (nativeBitmap.nChannels == 3)
{
format = System::Windows::Media::PixelFormats::Bgr24;
palette = System::Windows::Media::Imaging::BitmapPalettes::Halftone256;
}
else
{
throw gcnew System::InvalidOperationException("Unsupported number of channels " + nativeBitmap.nChannels);
}
//copy data
int pixelDataLength = nativeBitmap.rows*nativeBitmap.stride;
System::IntPtr source = System::IntPtr(nativeBitmap.data);
cli::array<unsigned char>^ buffer = gcnew cli::array<unsigned char>(pixelDataLength);
System::Runtime::InteropServices::Marshal::Copy(source, buffer, 0, pixelDataLength);
System::Windows::Media::Imaging::BitmapSource^ managedBitmap =
System::Windows::Media::Imaging::BitmapSource::Create(nativeBitmap.cols, nativeBitmap.rows,
96, 96,
format, palette,
buffer, nativeBitmap.stride);
return managedBitmap;
}
我正在一个简单的单通道案例上测试我的功能:
BSII::IP::Bitmap_8Bit native;
native.cols = 8;
native.rows = 4;
native.nChannels = 1;
native.stride = 8;
int dataLength = native.stride * native.rows;
native.data = new unsigned char[dataLength];
unsigned char gray = 0;
for (int i = 0; i < native.rows; ++i)
{
for (int j = 0; j < native.cols; ++j)
{
native.data[native.stride*i + j] = gray;
gray += 10;
}
}
System::Windows::Media::Imaging::BitmapSource^ managed = msclr::interop::marshal_as<System::Windows::Media::Imaging::BitmapSource^>(native);
System::IO::FileStream^ stream = gcnew System::IO::FileStream("c:''workspace''temp''managed.bmp", System::IO::FileMode::Create);
System::Windows::Media::Imaging::BmpBitmapEncoder^ encoder = gcnew System::Windows::Media::Imaging::BmpBitmapEncoder();
System::Windows::Media::Imaging::BitmapFrame^ bitmapFrame = System::Windows::Media::Imaging::BitmapFrame::Create(managed);
encoder->Frames->Add(bitmapFrame);
encoder->Save(stream);
stream->Close();
这行不通。当我调试它时,我看到缓冲区数组中有正确的值,但当我将BitmapSource保存到图像中时,它看起来不像应该的那样。
我还试着用nullptr代替Grey256或Halftone256作为调色板,但它也不起作用。
我想我在使用BitmapSource时遗漏了一些东西。有什么想法吗?
谢谢,Dina
使用PngBitmapEncoder
而不是BmpBitmapEncoder
。BmpBitmapEncoder
使图像变形。使用PngBitmapEncoder
,示例工作正常。
同样出于性能原因,请尝试使用:
BitmapSource.Create(Int32, Int32, Double, Double, PixelFormat, BitmapPalette,
IntPtr, Int32, Int32)
而不是
BitmapSource.Create(Int32, Int32, Double, Double, PixelFormat, BitmapPalette,
Array, Int32)