如何顺序更改WPF中没有UI延迟的图像源?
我从USB获取图像的序列,并抓住每个图像我将抓取的结果转换为System.Drawing.Bitmap,然后将其转换为System.Windows.Mesia.Imging.BitmapImage以便能够将它分配给Imagesource和最后在调度程序线程中更新UI,所有这些过程都需要时间并且不会实时生效,相机公司(Basler)的示例代码使用C#并直接将System.Drawing.Bitmap分配给图片框,并且可以不显示实时视图延迟。 什么是处理它的最佳解决方案?值得一提的是2048 * 2000像素大小的帧速率几乎是50 fps的如何顺序更改WPF中没有UI延迟的图像源?
PixelDataConverter converter = new PixelDataConverter();
Bitmap bitmap = new Bitmap(grabResult.Width, grabResult.Height, PixelFormat.Format32bppRgb);
BitmapData bmpData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
converter.OutputPixelFormat = PixelType.BGRA8packed;
IntPtr ptrBmp = bmpData.Scan0;
converter.Convert(ptrBmp, bmpData.Stride * bitmap.Height, grabResult);
bitmap.UnlockBits(bmpData);
BitmapImage bitmapimage = new BitmapImage();
using (MemoryStream memory = new MemoryStream())
{
bitmap.Save(memory, ImageFormat.Bmp);
memory.Position = 0;
bitmapimage.BeginInit();
bitmapimage.StreamSource = memory;
bitmapimage.CacheOption = BitmapCacheOption.OnLoad;
bitmapimage.EndInit();
bitmapimage.Freeze();
}
Dispatcher.Invoke(new Action(() =>
{
imgMain.Source = bitmapimage;
}));
这是公司为C#示例代码:
Bitmap bitmap = new Bitmap(grabResult.Width, grabResult.Height, PixelFormat.Format32bppRgb);
// Lock the bits of the bitmap.
BitmapData bmpData = bitmap.LockBits(new Rectangle(0, 0, bitmap.Width, bitmap.Height), ImageLockMode.ReadWrite, bitmap.PixelFormat);
// Place the pointer to the buffer of the bitmap.
converter.OutputPixelFormat = PixelType.BGRA8packed;
IntPtr ptrBmp = bmpData.Scan0;
converter.Convert(ptrBmp, bmpData.Stride * bitmap.Height, grabResult); //Exception handling TODO
bitmap.UnlockBits(bmpData);
// Assign a temporary variable to dispose the bitmap after assigning the new bitmap to the display control.
Bitmap bitmapOld = pictureBox.Image as Bitmap;
// Provide the display control with the new bitmap. This action automatically updates the display.
pictureBox.Image = bitmap;
if (bitmapOld != null)
{
// Dispose the bitmap.
bitmapOld.Dispose();
}
}
enter code here
使用Dispatcher.BeginInvoke代替Dispatcher.Invoke(...
设置图像异步。
Dispatcher.BeginInvoke(DispatcherPriority.Input, new Action(() =>
{
imgMain.Source = bitmapimage;
}));
它没有解决问题仍然延迟 –
我知道,但为什么它仍然延迟UI像@Majid khalili说 –
“* 2048 * 2000像素大小帧速率几乎50 fps *”意味着创建一个相当大的位图,将其作为BMP编码到MemoryStream中,并在20毫秒内从流中解码出BitmapSource。 – Clemens
尝试设置OutputPixelFormat属性到由所述WPF的BitmapSource类支持的格式(见[的PixelFormats](https://msdn.microsoft.com/en-us/library/system.windows.media .pixelformats(v = vs.110)的.aspx))。然后直接调用[BitmapSource.Create()](https://msdn.microsoft.com/en-us/library/system.windows.media.imaging.bitmapsource.create(v = vs.110).aspx)。 – Clemens