我编写了将jpeg缩放并存储到文件中的函数,如下所示
bool ResizeJpeg(unsigned char* _jpegDataBuff, int _buffLength, int _newSize_X, int _newSize_Y)
{
try
{
//Decode to bitmap
UnmanagedMemoryStream^ mStream = gcnew UnmanagedMemoryStream(_jpegDataBuff, _buffLength);
JpegBitmapDecoder^ decoder = gcnew JpegBitmapDecoder(mStream, BitmapCreateOptions::PreservePixelFormat, BitmapCacheOption::OnLoad);
BitmapSource^ bitmapSource = decoder->Frames[0];
//Scale bitmap into new size
BitmapSource^ bitmapSourceScaled = ResizeBitmap(bitmapSource, _newSize_X, _newSize_Y);
//Encode to Jpeg
FileStream^ fileStream = gcnew FileStream("1.jpg", FileMode::Create);
JpegBitmapEncoder^ encoder = gcnew JpegBitmapEncoder();
encoder->QualityLevel = _quality;
encoder->Frames->Add(BitmapFrame::Create(bitmapSourceScaled));
encoder->Save(fileStream);
fileStream->Close();
return true;
}
catch (System::Exception^)
{
return false;
}
}
BitmapSource ResizeBitmap(BitmapSource source, double nWidth, double nHeight)
{
TransformedBitmap tbBitmap = new TransformedBitmap(source,
new ScaleTransform(nWidth / source.PixelWidth,
nHeight / source.PixelHeight, 0, 0));
return tbBitmap;
}
此代码工作正常,但有时它会导致结果图像损坏,如下所示
请帮帮我,如何修复这个错误?
非常感谢!
T& T公司