C#中使用byte[]数据，生成Bitmap

/// <summary>

/// 使用byte[]数据生成色灰度BMP 位图

/// </summary>

/// <param name=originalImageData></param>

/// <param name=originalWidth></param>

/// <param name=originalHeight></param>

/// <returns></returns>

public static Bitmap CreateBitmap(byte[] originalImageData int originalWidth int originalHeight)

{

//指定位格式即色

Bitmap resultBitmap = new Bitmap(originalWidth originalHeight SystemDrawingImagingPixelFormatFormatbppIndexed);

//将该位图存入内存中

MemoryStream curImageStream = new MemoryStream();

resultBitmapSave(curImageStream SystemDrawingImagingImageFormatBmp);

curImageStreamFlush();

//由于位图数据需要DWORD对齐（byte倍数）计算需要补位的个数

int curPadNum = ((originalWidth * + ) / * ) originalWidth;

//最终生成的位图数据大小

int bitmapDataSize = ((originalWidth * + ) / * ) * originalHeight;

//数据部分相对文件开始偏移具体可以参考位图文件格式

int dataOffset = ReadData(curImageStream );

//改变调色板因为默认的调色板是位彩色的需要修改为色的调色板

int paletteStart = ;

int paletteEnd = dataOffset;

int color = ;

for (int i = paletteStart; i < paletteEnd; i += )

{

byte[] tempColor = new byte[];

tempColor[] = (byte)color;

tempColor[] = (byte)color;

tempColor[] = (byte)color;

tempColor[] = (byte);

color++;

curImageStreamPosition = i;

curImageStreamWrite(tempColor );

}

//最终生成的位图数据以及大小高度没有变宽度需要调整

byte[] destImageData = new byte[bitmapDataSize];

int destWidth = originalWidth + curPadNum;

//生成最终的位图数据注意的是位图数据 从左到右从下到上所以需要颠倒

for (int originalRowIndex = originalHeight ; originalRowIndex >= ; originalRowIndex)

{

int destRowIndex = originalHeight originalRowIndex ;

for (int dataIndex = ; dataIndex < originalWidth; dataIndex++)

{

//同时还要注意新的位图数据的宽度已经变化destWidth否则会产生错位

destImageData[destRowIndex * destWidth + dataIndex] = originalImageData[originalRowIndex * originalWidth + dataIndex];

}

}

//将流的Position移到数据段

curImageStreamPosition = dataOffset;

//将新位图数据写入内存中

curImageStreamWrite(destImageData bitmapDataSize);

curImageStreamFlush();

//将内存中的位图写入Bitmap对象

resultBitmap = new Bitmap(curImageStream);

return resultBitmap;

}

/// <summary>

/// 从内存流中指定位置读取数据

/// </summary>

/// <param name=curStream></param>

/// <param name=startPosition></param>

/// <param name=length></param>

/// <returns></returns>

public static int ReadData(MemoryStream curStream int startPosition int length)

{

int result = ;

byte[] tempData = new byte[length];

curStreamPosition = startPosition;

curStreamRead(tempData length);

result = BitConverterToInt(tempData );

return result;

}

/// <summary>

/// 向内存流中指定位置写入数据

/// </summary>

/// <param name=curStream></param>

/// <param name=startPosition></param>

/// <param name=length></param>

/// <param name=value></param>

public static void WriteData(MemoryStream curStream int startPosition int length int value)

{

curStreamPosition = startPosition;

curStreamWrite(BitConverterGetBytes(value) length);

}