最近学习emgucv，我在写读摄像头的程序然后需要bitmap 转texture2D 其实可以直接使用setdata<bytes>的方法赋值，感觉帧率不是一般的低，是无法忍受的。
也试了多种方法，基本上都是无法忍受的。可能有人会用得到，将搜集的列下来。
这是一些方法的搜集。
Texture2D toBitmap 的方法
public static Bitmap FastTextureToBitmap(Texture2D texture)
{
// Setup pointer back to bitmap
Bitmap newBitmap = new Bitmap(texture.Width, texture.Height);
// Get color data from the texture
Microsoft.Xna.Framework.Graphics.Color[ textureColors = GetColorDataFromTexture(texture);
System.Drawing.Imaging.BitmapData bmpData = newBitmap.LockBits(new System.Drawing.Rectangle(0, 0, newBitmap.Width, newBitmap.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
// Loop through pixels and set values
unsafe
{
byte* bmpPointer = (byte*)bmpData.Scan0;
for (int y = 0; y < texture.Height; y++)
{
for (int x = 0; x < texture.Width; x++)
{
bmpPointer[0] = textureColors[x + y * texture.Width].B;
bmpPointer[1] = textureColors[x + y * texture.Width].G;
bmpPointer[2] = textureColors[x + y * texture.Width].R;
bmpPointer[3] = textureColors[x + y * texture.Width].A;
bmpPointer += 4;
}
bmpPointer += bmpData.Stride - (bmpData.Width * 4);
}
}
textureColors = null;
newBitmap.UnlockBits(bmpData);
return newBitmap;
}
bitmap to texture2D 的方法：
private Texture2D GetTexture(GraphicsDevice dev, System.Drawing.Bitmap bmp)
{
int[] imgData = new int[bmp.Width * bmp.Height];
Texture2D texture = new Texture2D(dev, bmp.Width, bmp.Height);
unsafe
{
// lock bitmap
System.Drawing.Imaging.BitmapData origdata =
bmp.LockBits(new System.Drawing.Rectangle(0, 0, bmp.Width, bmp.Height), System.Drawing.Imaging.ImageLockMode.ReadOnly, bmp.PixelFormat);
uint* byteData = (uint*)origdata.Scan0;
// Switch bgra -> rgba
for (int i = 0; i < imgData.Length; i++)
{
byteData[i] = (byteData[i] & 0x000000ff) << 16 | (byteData[i] & 0x0000FF00) | (byteData[i] & 0x00FF0000) >> 16 | (byteData[i] & 0xFF000000);
}
// copy data
System.Runtime.InteropServices.Marshal.Copy(origdata.Scan0, imgData, 0, bmp.Width * bmp.Height);
byteData = null;
// unlock bitmap
bmp.UnlockBits(origdata);
}
texture.SetData(imgData);
return texture;
}貌似对于赋值这一步C#的效率好像不高，帧率一般都会降的很低。我还没有想到更好的办法，表示无奈中。。。
实际上还有一个方法可以直接使用
BitmapSourceExtensions.CopyTo Method (BitmapSource, Texture2D)
此方法需要使用 System.Windows.Media.Imaging 我倒还没有尝试过。估计应该是挺好用的。
例子可以参见http://msdn.microsoft.com/en-us/library/gg712857(v=vs.96).aspx
这种方法试过，但是不管用，自己也是新手，搞不定了。。。就扔了，有人搞懂的话，可以回个帖。~
值得一提的是对于BITMAP的格式，要值得仔细查看一下，不要直接套用上面的方法
这个是另外一种方法，试了一下貌似帧率有所提高，但依然还是不如窗体直接用的那种性能好。都准备放弃XNA了。。。
1publicstatic Texture2D BitmapToTexture2D(
2 GraphicsDevice GraphicsDevice,
3 System.Drawing.Bitmap image)
4{
5 // Buffer size is size of color array multiplied by 4 because
6// each pixel has four color bytes
7int bufferSize = image.Height * image.Width * 4;
8
9 // Create new memory stream and save image to stream so
10// we don't have to save and read file
11 System.IO.MemoryStream memoryStream =
12 new System.IO.MemoryStream(bufferSize);
13 image.Save(memoryStream, System.Drawing.Imaging.ImageFormat.Png);
14 15 // Creates a texture from IO.Stream - our memory stream
16 Texture2D texture = Texture2D.FromStream(
17 GraphicsDevice, memoryStream);
18 19return texture;
20} 我依然觉得这是个性能瓶颈。。。又搜到了国外某人发的一个类
using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using System.Drawing;
using System.Drawing.Imaging;
using System.Runtime.InteropServices;
namespace MrXNAHelper
{
public class ImageToTexture
{
byte[] bmpBytes;
Texture2D background;
int width, height;
Game game;
public ImageToTexture(Game game, int width, int height)
{
this.width = width;
this.height = height;
this.game = game;
GenerateBitmap(game, width, height);
}
public ImageToTexture(Game game)
{
this.game = game;
}
private void GenerateBitmap(Game game, int width, int height)
{
background = new Texture2D(game.GraphicsDevice, width, height);
}
public Texture2D ConvertBitmapToTexture(Bitmap b)
{
game.GraphicsDevice.Textures[0] = null;
if (background == null ||
b.Width != background.Width ||
b.Height != background.Height)
{
width = b.Width;
height = b.Height;
GenerateBitmap(game, width, height);
}
BitmapData bData = b.LockBits(new System.Drawing.Rectangle(new System.Drawing.Point(), b.Size),
ImageLockMode.ReadOnly,
PixelFormat.Format32bppRgb);
// number of bytes in the bitmap
int byteCount = bData.Stride * b.Height;
if (bmpBytes == null ||
bmpBytes.Length != byteCount)
bmpBytes = new byte[byteCount];
// Copy the locked bytes from memory
Marshal.Copy(bData.Scan0, bmpBytes, 0, byteCount);
// don't forget to unlock the bitmap!!
b.UnlockBits(bData);
background.SetData(bmpBytes);
return background;
}
}
}
现在知道降低XNA帧率或者自己写个定时器，总之不要使用60Hz的话，好像帧率也会有很大的提高。
byte[] bgrData = nextFrame.Bytes;
for (int i = 0; i < colorData.Length; i++)
colorData[i] = new Color(bgrData[3 * i + 2], bgrData[3 * i + 1], bgrData[3 * i]);
