問題描述

我在 TCP 客戶端接收到一個 byte[] 數組.該數組包含一個 24 位 RGB 位圖文件.如何創建具有給定寬度、高度和數據的位圖文件?

I have a byte[] array received in TCP Client.The array contains a 24-bit RGB Bitmap file.How to create that bitmap file with given Width ,Height and data?

在 C++ 中我使用這個

In C++ I use this

int WriteBitmapFile(const char *filename, int width, int height, unsigned char *imageData)
{
FILE             *filePtr;        // file pointer
BITMAPFILEHEADER bitmapFileHeader;    // bitmap file header
BITMAPINFOHEADER bitmapInfoHeader;    // bitmap info header
DWORD                 imageIdx;    // used for swapping RGB->BGR
unsigned char     tempRGB;            // used for swapping

// open file for writing binary mode
filePtr = fopen(filename, "wb");
if (!filePtr)
    return 0;

// define the bitmap file header
bitmapFileHeader.bfSize = sizeof(BITMAPFILEHEADER);
bitmapFileHeader.bfType = 0x4D42;
bitmapFileHeader.bfReserved1 = 0;
bitmapFileHeader.bfReserved2 = 0;
bitmapFileHeader.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);

// define the bitmap information header
bitmapInfoHeader.biSize = sizeof(BITMAPINFOHEADER);
bitmapInfoHeader.biPlanes = 1;
bitmapInfoHeader.biBitCount = 32;                        // 24-bit
bitmapInfoHeader.biCompression = BI_RGB;                // no compression
bitmapInfoHeader.biSizeImage = width * abs(height) * 4;    // width * height * (RGB bytes)
bitmapInfoHeader.biXPelsPerMeter = 0;
bitmapInfoHeader.biYPelsPerMeter = 0;
bitmapInfoHeader.biClrUsed = 0;
bitmapInfoHeader.biClrImportant = 0;
bitmapInfoHeader.biWidth = width;                        // bitmap width
bitmapInfoHeader.biHeight = height;                    // bitmap height

// switch the image data from RGB to BGR
for(imageIdx = 0; imageIdx < bitmapInfoHeader.biSizeImage; imageIdx+=4)
{
    tempRGB = imageData[imageIdx];
    imageData[imageIdx] = imageData[imageIdx + 2];
    imageData[imageIdx + 2] = tempRGB;
}

// write the bitmap file header
fwrite(&bitmapFileHeader, 1, sizeof(BITMAPFILEHEADER), filePtr);

// write the bitmap info header
fwrite(&bitmapInfoHeader, 1, sizeof(BITMAPINFOHEADER), filePtr);

// write the image data
fwrite(imageData, 1, bitmapInfoHeader.biSizeImage, filePtr);

// close our file
fclose(filePtr);

// Success
return 1;
}

我怎么能在 C# 中做到這一點?

How could I do that in C#?

推薦答案

如果數組實際上包含一個位圖文件，那么您可以將字節保存為文件:

If the array actually contains a bitmap file, then you can just save the bytes as a file:

File.WriteAllBytes(fileName, imageData);

如果數組只包含原始像素數據，您可以使用該數據創建一個 Bitmap 對象:

If the array contains only raw pixel data, you can create a Bitmap object using the data:

unsafe {
   fixed (byte* ptr = imageData) {
      using (Bitmap image = new Bitmap(width, height, stride, PixelFormat.Format24bppRgb, new IntPtr(ptr))) {
         image.Save(fileName);
      }
   }
}

stride 值是掃描線之間的字節數.如果掃描線之間沒有填充，則為 24bpp 格式的 width * 3.

The stride value is the number of bytes between the scan lines. If there is no padding between the scan lines, it's width * 3 for a 24bpp format.

此方法使用數組中的數據，而無需在內存中創建整個圖像的另一個副本(這就是它需要步幅值的原因).

This method uses the data in the array without creating another copy of the entire image in memory (which is why it needs the stride value).

如果位圖數據倒置存放在數組中，stride的值應該是負的，指針應該是內存中最后一個掃描行的開始(ptr + stride* (高度 - 1)).

If the bitmap data is stored upside down in the array, the stride value should be negative, and the pointer should be the start of the last scan line in memory (ptr + stride * (height - 1)).

這篇關于如何在 C# 中從 byte[] 創建 bmp 文件的文章就介紹到這了，希望我們推薦的答案對大家有所幫助，也希望大家多多支持html5模板網！