www.pudn.com > jpeglib.rar > Bmpfile.cpp
// bmpops.cpp : implementation of the BMPFile class
//
// This handles the reading and writing of BMP files.
//
//
#include "stdafx.h"
#include "bmpfile.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
BMPFile::BMPFile()
{
m_errorText="OK";
}
////////////////////////////////////////////////////////////////////////////
// load a .BMP file - 1,4,8,24 bit
//
// allocates and returns an RGB buffer containing the image.
// modifies width and height accordingly - NULL, 0, 0 on error
BYTE * BMPFile::LoadBMP(CString fileName,
UINT *width,
UINT *height)
{
BITMAP inBM;
BYTE m1,m2;
long filesize;
short res1,res2;
long pixoff;
long bmisize;
long compression;
unsigned long sizeimage;
long xscale, yscale;
long colors;
long impcol;
BYTE *outBuf=NULL;
// for safety
*width=0; *height=0;
// init
m_errorText="OK";
m_bytesRead=0;
FILE *fp;
fp=fopen(fileName,"rb");
if (fp==NULL) {
CString msg;
msg="Can't open file for reading :\n"+fileName;
m_errorText=msg;
return NULL;
} else {
long rc;
rc=fread((BYTE *)&(m1),1,1,fp); m_bytesRead+=1;
if (rc==-1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((BYTE *)&(m2),1,1,fp); m_bytesRead+=1;
if (rc==-1) m_errorText="Read Error!";
if ((m1!='B') || (m2!='M')) {
m_errorText="Not a valid BMP File";
fclose(fp);
return NULL;
}
////////////////////////////////////////////////////////////////////////////
//
// read a ton of header stuff
rc=fread((long *)&(filesize),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((int *)&(res1),2,1,fp); m_bytesRead+=2;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((int *)&(res2),2,1,fp); m_bytesRead+=2;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(pixoff),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(bmisize),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(inBM.bmWidth),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(inBM.bmHeight),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((int *)&(inBM.bmPlanes),2,1,fp); m_bytesRead+=2;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((int *)&(inBM.bmBitsPixel),2,1,fp); m_bytesRead+=2;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(compression),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(sizeimage),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(xscale),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(yscale),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(colors),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
rc=fread((long *)&(impcol),4,1,fp); m_bytesRead+=4;
if (rc!=1) {m_errorText="Read Error!"; fclose(fp); return NULL;}
////////////////////////////////////////////////////////////////////////////
// i don't do RLE files
if (compression!=BI_RGB) {
m_errorText="This is a compressed file.";
fclose(fp);
return NULL;
}
if (colors == 0) {
colors = 1 << inBM.bmBitsPixel;
}
////////////////////////////////////////////////////////////////////////////
// read colormap
RGBQUAD *colormap = NULL;
switch (inBM.bmBitsPixel) {
case 24:
break;
// read pallete
case 1:
case 4:
case 8:
colormap = new RGBQUAD[colors];
if (colormap==NULL) {
fclose(fp);
m_errorText="Out of memory";
return NULL;
}
int i;
for (i=0;ipixoff) {
fclose(fp);
m_errorText="Corrupt palette";
delete [] colormap;
fclose(fp);
return NULL;
}
while ((long)m_bytesRead=0;row--) {
// which row are we working on?
rowOffset=(long unsigned)row*row_size;
if (inBM.bmBitsPixel==24) {
for (int col=0;col> bit_count) & mask;
// lookup the color from the colormap - stuff it in our buffer
// swap red and blue
*(outBuf + rowOffset + col * 3 + 2) = colormap[pix].rgbBlue;
*(outBuf + rowOffset + col * 3 + 1) = colormap[pix].rgbGreen;
*(outBuf + rowOffset + col * 3 + 0) = colormap[pix].rgbRed;
}
// read DWORD padding
while ((m_bytesRead-pixoff)&3) {
char dummy;
if (fread(&dummy,1,1,fp)!=1) {
m_errorText="Read Error";
delete [] outBuf;
if (colormap)
delete [] colormap;
fclose(fp);
return NULL;
}
m_bytesRead++;
}
}
}
}
if (colormap) {
delete [] colormap;
}
fclose(fp);
}
return outBuf;
}
////////////////////////////////////////////////////////////////////////////
// write a 24-bit BMP file
//
// image MUST be a packed buffer (not DWORD-aligned)
// image MUST be vertically flipped !
// image MUST be BGR, not RGB !
//
void BMPFile::SaveBMP(CString fileName, // output path
BYTE * buf, // BGR buffer
UINT width, // pixels
UINT height)
{
short res1=0;
short res2=0;
long pixoff=54;
long compression=0;
long cmpsize=0;
long colors=0;
long impcol=0;
char m1='B';
char m2='M';
m_errorText="OK";
DWORD widthDW = WIDTHBYTES(width * 24);
long bmfsize=sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER) +
widthDW * height;
long byteswritten=0;
BITMAPINFOHEADER header;
header.biSize=40; // header size
header.biWidth=width;
header.biHeight=height;
header.biPlanes=1;
header.biBitCount=24; // RGB encoded, 24 bit
header.biCompression=BI_RGB; // no compression
header.biSizeImage=0;
header.biXPelsPerMeter=0;
header.biYPelsPerMeter=0;
header.biClrUsed=0;
header.biClrImportant=0;
FILE *fp;
fp=fopen(fileName,"wb");
if (fp==NULL) {
m_errorText="Can't open file for writing";
return;
}
// should probably check for write errors here...
fwrite((BYTE *)&(m1),1,1,fp); byteswritten+=1;
fwrite((BYTE *)&(m2),1,1,fp); byteswritten+=1;
fwrite((long *)&(bmfsize),4,1,fp); byteswritten+=4;
fwrite((int *)&(res1),2,1,fp); byteswritten+=2;
fwrite((int *)&(res2),2,1,fp); byteswritten+=2;
fwrite((long *)&(pixoff),4,1,fp); byteswritten+=4;
fwrite((BITMAPINFOHEADER *)&header,sizeof(BITMAPINFOHEADER),1,fp);
byteswritten+=sizeof(BITMAPINFOHEADER);
long row=0;
long rowidx;
long row_size;
row_size=header.biWidth*3;
long rc;
for (row=0;row 8) {
m_errorText="Error : nBits > 8????";
fclose(fp);
return;
}
if (nbits == 8) {
putc(pixbuf, fp);
pixbuf=0;
nbits=0;
byteswritten++;
}
} // cols
if (nbits > 0) {
putc(pixbuf, fp); // write partially filled byte
byteswritten++;
}
// DWORD align
while ((byteswritten -pixeloffset) & 3) {
putc(0, fp);
byteswritten++;
}
} //rows
if (byteswritten!=filesize) {
m_errorText="byteswritten != filesize";
}
fclose(fp);
}