如何创建一个1bpp位图 [英] How to create a 1bpp Bitmap

问题描述

大家好，

我正在尝试开发一个使用VS2008(vc ++)将像素信息保存为位图文件的应用程序.目前，我有一个包含像素数据的字节缓冲区，每个像素格式为1位.图像的宽度和列为512 x512.我使用Lockbits()方法创建位图数据，并使用Bitmap :: Save()方法将其保存在bmp文件中.但是问题在于，从位图看来，一些数据已经丢失并且图像不清楚.

您能帮我创建一个1bpp位图吗?

我使用的代码是:

Hi All,

I''m trying to develop an application that saves a pixel information as bitmap file using VS2008 ( vc++ ). Currently, i have a byte buffer containing pixel data, which is in 1 bit per pixel format. The width and column of the image is 512 x 512. I used Lockbits() method to create the bitmap data and used Bitmap::Save() method to save it in a bmp file. But the problem is that, from the bitmap it seems that some data has been lost and image is not clear.

Could you please help me to create a 1bpp Bitmap ?

The code i used is:

<br />
int nNumComps = pstImageInfo_i->usBitsAllocated;<br />
         short sSamplesPerPixel = 1;<br />
         int nWidth = pstImageInfo_i->usColumns;<br />
         int nHeight = pstImageInfo_i->usRows;         <br />
         int nFormat = PixelFormat1bppIndexed;<br />
         int nNumColors = 2;<br />
         ColorPalette* pPalette = 0;<br />
        pPalette = reinterpret_cast< ColorPalette* >( malloc( sizeof( ColorPalette ) + <br />
                                                              ( nNumColors - 1 )<br />
                                                              * sizeof( ARGB )));<br />
        if( 0 != pPalette )<br />
        {<br />
            pPalette->Flags = PaletteFlagsGrayScale;<br />
            pPalette->Count = nNumColors;<br />
            Color clr( 255, 0, 0, 0 );<br />
            pPalette->Entries[0] = clr.GetValue();<br />
            Color clrWhite( 255, 255, 255, 255 );<br />
            pPalette->Entries[1] = clrWhite.GetValue();<br />
        }<br />
        Bitmap bmpOverlay( nWidth, nHeight, nFormat );<br />
        BitmapData btmpData;<br />
        ZeroMemory( &btmpData, sizeof( btmpData ));<br />
        Rect BMPRect( 0, 0, nWidth, nHeight );<br />
        bmpOverlay.LockBits( &BMPRect, ImageLockModeWrite,<br />
                             nFormat, &btmpData );<br />
        //btmpData.Stride = -btmpData.Stride;<br />
        int nSize = pstImageInfo_i->dwBufferSize;<br />
        // Considering only 1 frame<br />
        if( pstImageInfo_i->usFramesInOverlay > 1 )<br />
        {<br />
            nSize = nSize / pstImageInfo_i->usFramesInOverlay;<br />
        }<br />
         memcpy( btmpData.Scan0, pstImageInfo_i->pbData,<br />
                  nSize );<br />
        bmpOverlay.UnlockBits( &btmpData );<br />
        Status ReturnStatus = bmpOverlay.RotateFlip( RotateNoneFlipY );<br />
        if( Ok ==  ReturnStatus )<br />
        {<br />
            if( pPalette )<br />
            {<br />
                ReturnStatus = bmpOverlay.SetPalette( pPalette );<br />
                delete pPalette;<br />
                pPalette = 0;<br />
            }<br />
        }<br />
         CLSID bmpClsid;<br />
         GetEncoderClsid(L"image/bmp", &bmpClsid);<br />
         bmpOverlay.Save( _T( "ImageOverlay.bmp" ), &bmpClsid, NULL );<br />

在此先感谢，
Aneev

Thanks in Advance,
Aneev

推荐答案

Aneev S写道:

Aneev S wrote:

但是问题是，从位图，似乎有些数据已丢失并且图像不清楚.

But the problem is that, from the bitmap it seems that some data has been lost and image is not clear.

我假设您将其另存为jpg. jpg文件格式可以做到这一点.

I assume you saved it as a jpg. The jpg file format does that.

显示用于创建&的代码.保存BMP.通常，用于减少BPP的功能会使图像抖动，这很可能是您解释为丢失的数据".

Show the code you used to create & save the BMP. It is common that the functions used to reduce the BPP will dither the image, which is likely what you are interpreting as "lost data".

我将创建并保存位图，如下所示: ):

I would create and save the bitmap as following :) :

...
  HBITMAP hBMP = CreateDIBSection(..);
...
  CImage cImage;
  cImage.Attach(hBMP);
  cImage.Save(..);
...

这篇关于如何创建一个1bpp位图的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！