gusucode.com > VC++ 图像处理类库CxImage源代码-源码程序 > VC++ 图像处理类库CxImage源代码-源码程序/code/cximage_src/CxImage/ximabmp.cpp
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/*
* File: ximabmp.cpp
* Purpose: Platform Independent BMP Image Class Loader and Writer
* 07/Aug/2001 Davide Pizzolato - www.xdp.it
* CxImage version 6.0.0 02/Feb/2008
*/
#include "ximabmp.h"
#if CXIMAGE_SUPPORT_BMP
#include "ximaiter.h"
////////////////////////////////////////////////////////////////////////////////
#if CXIMAGE_SUPPORT_ENCODE
////////////////////////////////////////////////////////////////////////////////
bool CxImageBMP::Encode(CxFile * hFile)
{
if (EncodeSafeCheck(hFile)) return false;
BITMAPFILEHEADER hdr;
hdr.bfType = 0x4d42; // 'BM' WINDOWS_BITMAP_SIGNATURE
hdr.bfSize = GetSize() + 14 /*sizeof(BITMAPFILEHEADER)*/;
hdr.bfReserved1 = hdr.bfReserved2 = 0;
hdr.bfOffBits = 14 /*sizeof(BITMAPFILEHEADER)*/ + head.biSize + GetPaletteSize();
hdr.bfType = ntohs(hdr.bfType);
hdr.bfSize = ntohl(hdr.bfSize);
hdr.bfOffBits = ntohl(hdr.bfOffBits);
#if CXIMAGE_SUPPORT_ALPHA
if (GetNumColors()==0 && AlphaIsValid()){
BITMAPINFOHEADER infohdr;
memcpy(&infohdr,&head,sizeof(BITMAPINFOHEADER));
infohdr.biCompression = BI_RGB;
infohdr.biBitCount = 32;
DWORD dwEffWidth = ((((infohdr.biBitCount * infohdr.biWidth) + 31) / 32) * 4);
infohdr.biSizeImage = dwEffWidth * infohdr.biHeight;
hdr.bfSize = infohdr.biSize + infohdr.biSizeImage + 14 /*sizeof(BITMAPFILEHEADER)*/;
hdr.bfSize = ntohl(hdr.bfSize);
bihtoh(&infohdr);
// Write the file header
hFile->Write(&hdr,min(14,sizeof(BITMAPFILEHEADER)),1);
hFile->Write(&infohdr,sizeof(BITMAPINFOHEADER),1);
//and DIB+ALPHA interlaced
BYTE *srcalpha = AlphaGetPointer();
for(long y = 0; y < infohdr.biHeight; ++y){
BYTE *srcdib = GetBits(y);
for(long x = 0; x < infohdr.biWidth; ++x){
hFile->Write(srcdib,3,1);
hFile->Write(srcalpha,1,1);
srcdib += 3;
++srcalpha;
}
}
} else
#endif //CXIMAGE_SUPPORT_ALPHA
{
// Write the file header
hFile->Write(&hdr,min(14,sizeof(BITMAPFILEHEADER)),1);
//copy attributes
memcpy(pDib,&head,sizeof(BITMAPINFOHEADER));
bihtoh((BITMAPINFOHEADER*)pDib);
// Write the DIB header and the pixels
hFile->Write(pDib,GetSize(),1);
bihtoh((BITMAPINFOHEADER*)pDib);
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif //CXIMAGE_SUPPORT_ENCODE
////////////////////////////////////////////////////////////////////////////////
#if CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
bool CxImageBMP::Decode(CxFile * hFile)
{
if (hFile == NULL) return false;
BITMAPFILEHEADER bf;
DWORD off = hFile->Tell(); //<CSC>
cx_try {
if (hFile->Read(&bf,min(14,sizeof(bf)),1)==0) cx_throw("Not a BMP");
bf.bfSize = ntohl(bf.bfSize);
bf.bfOffBits = ntohl(bf.bfOffBits);
if (bf.bfType != BFT_BITMAP) { //do we have a RC HEADER?
bf.bfOffBits = 0L;
hFile->Seek(off,SEEK_SET);
}
BITMAPINFOHEADER bmpHeader;
if (!DibReadBitmapInfo(hFile,&bmpHeader)) cx_throw("Error reading BMP info");
DWORD dwCompression=bmpHeader.biCompression;
DWORD dwBitCount=bmpHeader.biBitCount; //preserve for BI_BITFIELDS compression <Thomas Ernst>
bool bIsOldBmp = bmpHeader.biSize == sizeof(BITMAPCOREHEADER);
bool bTopDownDib = bmpHeader.biHeight<0; //<Flanders> check if it's a top-down bitmap
if (bTopDownDib) bmpHeader.biHeight=-bmpHeader.biHeight;
if (info.nEscape == -1) {
// Return output dimensions only
head.biWidth = bmpHeader.biWidth;
head.biHeight = bmpHeader.biHeight;
info.dwType = CXIMAGE_FORMAT_BMP;
cx_throw("output dimensions returned");
}
if (!Create(bmpHeader.biWidth,bmpHeader.biHeight,bmpHeader.biBitCount,CXIMAGE_FORMAT_BMP))
cx_throw("");
SetXDPI((long) floor(bmpHeader.biXPelsPerMeter * 254.0 / 10000.0 + 0.5));
SetYDPI((long) floor(bmpHeader.biYPelsPerMeter * 254.0 / 10000.0 + 0.5));
if (info.nEscape) cx_throw("Cancelled"); // <vho> - cancel decoding
RGBQUAD *pRgb = GetPalette();
if (pRgb){
if (bIsOldBmp){
// convert a old color table (3 byte entries) to a new
// color table (4 byte entries)
hFile->Read((void*)pRgb,DibNumColors(&bmpHeader) * sizeof(RGBTRIPLE),1);
for (int i=DibNumColors(&head)-1; i>=0; i--){
pRgb[i].rgbRed = ((RGBTRIPLE *)pRgb)[i].rgbtRed;
pRgb[i].rgbBlue = ((RGBTRIPLE *)pRgb)[i].rgbtBlue;
pRgb[i].rgbGreen = ((RGBTRIPLE *)pRgb)[i].rgbtGreen;
pRgb[i].rgbReserved = (BYTE)0;
}
} else {
hFile->Read((void*)pRgb,DibNumColors(&bmpHeader) * sizeof(RGBQUAD),1);
//force rgbReserved=0, to avoid problems with some WinXp bitmaps
for (unsigned int i=0; i<head.biClrUsed; i++) pRgb[i].rgbReserved=0;
}
}
if (info.nEscape) cx_throw("Cancelled"); // <vho> - cancel decoding
switch (dwBitCount) {
case 32 :
DWORD bfmask[3];
if (dwCompression == BI_BITFIELDS)
{
hFile->Read(bfmask, 12, 1);
} else {
bfmask[0]=0x00FF0000;
bfmask[1]=0x0000FF00;
bfmask[2]=0x000000FF;
}
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
if (dwCompression == BI_BITFIELDS || dwCompression == BI_RGB){
long imagesize=4*head.biHeight*head.biWidth;
BYTE* buff32=(BYTE*)malloc(imagesize);
if (buff32){
hFile->Read(buff32, imagesize,1); // read in the pixels
#if CXIMAGE_SUPPORT_ALPHA
if (dwCompression == BI_RGB){
AlphaCreate();
if (AlphaIsValid()){
bool bAlphaOk = false;
BYTE* p;
for (long y=0; y<head.biHeight; y++){
p = buff32 + 3 + head.biWidth * 4 * y;
for (long x=0; x<head.biWidth; x++){
if (*p) bAlphaOk = true;
AlphaSet(x,y,*p);
p+=4;
}
}
// fix if alpha pixels are all zero
if (!bAlphaOk) AlphaInvert();
}
}
#endif //CXIMAGE_SUPPORT_ALPHA
Bitfield2RGB(buff32,bfmask[0],bfmask[1],bfmask[2],32);
free(buff32);
} else cx_throw("can't allocate memory");
} else cx_throw("unknown compression");
break;
case 24 :
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
if (dwCompression == BI_RGB){
hFile->Read(info.pImage, head.biSizeImage,1); // read in the pixels
} else cx_throw("unknown compression");
break;
case 16 :
{
DWORD bfmask[3];
if (dwCompression == BI_BITFIELDS)
{
hFile->Read(bfmask, 12, 1);
} else {
bfmask[0]=0x7C00; bfmask[1]=0x3E0; bfmask[2]=0x1F; //RGB555
}
// bf.bfOffBits required after the bitfield mask <Cui Ying Jie>
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
// read in the pixels
hFile->Read(info.pImage, head.biHeight*((head.biWidth+1)/2)*4,1);
// transform into RGB
Bitfield2RGB(info.pImage,bfmask[0],bfmask[1],bfmask[2],16);
break;
}
case 8 :
case 4 :
case 1 :
if (bf.bfOffBits != 0L) hFile->Seek(off + bf.bfOffBits,SEEK_SET);
switch (dwCompression) {
case BI_RGB :
hFile->Read(info.pImage, head.biSizeImage,1); // read in the pixels
break;
case BI_RLE4 :
{
BYTE status_byte = 0;
BYTE second_byte = 0;
int scanline = 0;
int bits = 0;
BOOL low_nibble = FALSE;
CImageIterator iter(this);
for (BOOL bContinue = TRUE; bContinue && hFile->Read(&status_byte, sizeof(BYTE), 1);) {
switch (status_byte) {
case RLE_COMMAND :
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_ENDOFLINE :
bits = 0;
scanline++;
low_nibble = FALSE;
break;
case RLE_ENDOFBITMAP :
bContinue=FALSE;
break;
case RLE_DELTA :
{
// read the delta values
BYTE delta_x;
BYTE delta_y;
hFile->Read(&delta_x, sizeof(BYTE), 1);
hFile->Read(&delta_y, sizeof(BYTE), 1);
// apply them
bits += delta_x / 2;
scanline += delta_y;
break;
}
default :
hFile->Read(&second_byte, sizeof(BYTE), 1);
BYTE *sline = iter.GetRow(scanline);
for (int i = 0; i < status_byte; i++) {
if ((BYTE*)(sline+bits) < (BYTE*)(info.pImage+head.biSizeImage)){
if (low_nibble) {
if (i&1)
*(sline + bits) |= (second_byte & 0x0f);
else
*(sline + bits) |= (second_byte & 0xf0)>>4;
bits++;
} else {
if (i&1)
*(sline + bits) = (BYTE)(second_byte & 0x0f)<<4;
else
*(sline + bits) = (BYTE)(second_byte & 0xf0);
}
}
if ((i & 1) && (i != (status_byte - 1)))
hFile->Read(&second_byte, sizeof(BYTE), 1);
low_nibble = !low_nibble;
}
if ((((status_byte+1) >> 1) & 1 ) == 1)
hFile->Read(&second_byte, sizeof(BYTE), 1);
break;
};
break;
default :
{
BYTE *sline = iter.GetRow(scanline);
hFile->Read(&second_byte, sizeof(BYTE), 1);
for (unsigned i = 0; i < status_byte; i++) {
if ((BYTE*)(sline+bits) < (BYTE*)(info.pImage+head.biSizeImage)){
if (low_nibble) {
if (i&1)
*(sline + bits) |= (second_byte & 0x0f);
else
*(sline + bits) |= (second_byte & 0xf0)>>4;
bits++;
} else {
if (i&1)
*(sline + bits) = (BYTE)(second_byte & 0x0f)<<4;
else
*(sline + bits) = (BYTE)(second_byte & 0xf0);
}
}
low_nibble = !low_nibble;
}
}
break;
};
}
break;
}
case BI_RLE8 :
{
BYTE status_byte = 0;
BYTE second_byte = 0;
int scanline = 0;
int bits = 0;
CImageIterator iter(this);
for (BOOL bContinue = TRUE; bContinue && hFile->Read(&status_byte, sizeof(BYTE), 1);) {
switch (status_byte) {
case RLE_COMMAND :
hFile->Read(&status_byte, sizeof(BYTE), 1);
switch (status_byte) {
case RLE_ENDOFLINE :
bits = 0;
scanline++;
break;
case RLE_ENDOFBITMAP :
bContinue=FALSE;
break;
case RLE_DELTA :
{
// read the delta values
BYTE delta_x;
BYTE delta_y;
hFile->Read(&delta_x, sizeof(BYTE), 1);
hFile->Read(&delta_y, sizeof(BYTE), 1);
// apply them
bits += delta_x;
scanline += delta_y;
break;
}
default :
hFile->Read((void *)(iter.GetRow(scanline) + bits), sizeof(BYTE) * status_byte, 1);
// align run length to even number of bytes
if ((status_byte & 1) == 1)
hFile->Read(&second_byte, sizeof(BYTE), 1);
bits += status_byte;
break;
};
break;
default :
BYTE *sline = iter.GetRow(scanline);
hFile->Read(&second_byte, sizeof(BYTE), 1);
for (unsigned i = 0; i < status_byte; i++) {
if ((DWORD)bits<info.dwEffWidth){
*(sline + bits) = second_byte;
bits++;
} else {
break;
}
}
break;
};
}
break;
}
default :
cx_throw("compression type not supported");
}
}
if (bTopDownDib) Flip(); //<Flanders>
} cx_catch {
if (strcmp(message,"")) strncpy(info.szLastError,message,255);
if (info.nEscape == -1 && info.dwType == CXIMAGE_FORMAT_BMP) return true;
return false;
}
return true;
}
////////////////////////////////////////////////////////////////////////////////
/* ReadDibBitmapInfo()
*
* Will read a file in DIB format and return a global HANDLE to its
* BITMAPINFO. This function will work with both "old" and "new"
* bitmap formats, but will always return a "new" BITMAPINFO.
*/
bool CxImageBMP::DibReadBitmapInfo(CxFile* fh, BITMAPINFOHEADER *pdib)
{
if ((fh==NULL)||(pdib==NULL)) return false;
if (fh->Read(pdib,sizeof(BITMAPINFOHEADER),1)==0) return false;
bihtoh(pdib);
switch (pdib->biSize) // what type of bitmap info is this?
{
case sizeof(BITMAPINFOHEADER):
break;
case 64: //sizeof(OS2_BMP_HEADER):
fh->Seek((long)(64 - sizeof(BITMAPINFOHEADER)),SEEK_CUR);
break;
case sizeof(BITMAPCOREHEADER):
{
BITMAPCOREHEADER bc = *(BITMAPCOREHEADER*)pdib;
pdib->biSize = bc.bcSize;
pdib->biWidth = (DWORD)bc.bcWidth;
pdib->biHeight = (DWORD)bc.bcHeight;
pdib->biPlanes = bc.bcPlanes;
pdib->biBitCount = bc.bcBitCount;
pdib->biCompression = BI_RGB;
pdib->biSizeImage = 0;
pdib->biXPelsPerMeter = 0;
pdib->biYPelsPerMeter = 0;
pdib->biClrUsed = 0;
pdib->biClrImportant = 0;
fh->Seek((long)(sizeof(BITMAPCOREHEADER)-sizeof(BITMAPINFOHEADER)), SEEK_CUR);
}
break;
default:
//give a last chance
if (pdib->biSize>(sizeof(BITMAPINFOHEADER))&&
(pdib->biSizeImage>=(unsigned long)(pdib->biHeight*((((pdib->biBitCount*pdib->biWidth)+31)/32)*4)))&&
(pdib->biPlanes==1)&&(pdib->biClrUsed==0))
{
if (pdib->biCompression==BI_RGB)
fh->Seek((long)(pdib->biSize - sizeof(BITMAPINFOHEADER)),SEEK_CUR);
break;
}
return false;
}
FixBitmapInfo(pdib);
return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif //CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
#endif // CXIMAGE_SUPPORT_BMP
////////////////////////////////////////////////////////////////////////////////