Re: GDI+ Question

On Feb 29, 5:27 pm, "Mark Salsbery [MVP]"
<MarkSalsbery[MVP]@newsgroup.nospam> wrote:


Just a


Hi... well I am very unfamiliar with this process and this is what I
need to do. Currently there is a method that converts a JPG to a BMP
with the method below. I need to be able to do the same with a TIF. I
think I was told that using GDI+ to read the TIF and then write the
bits to a stream to get the DIB would be a method of doing this,
rather than doing it like the method below. What do you think?

BOOL Jpg2Bmp(PTERWND w,int input, LPBYTE InFile,HGLOBAL hBuf,long
BufLen, HGLOBAL far *hDIB, BOOL import)
{
    HFILE hFile=HFILE_ERROR;
    OFSTRUCT OpenBuf;
    struct StrJpg far *jpg=NULL;
    BYTE huge *InBuf=NULL;
    BYTE marker;
    int i;
    BOOL IsJpgFile=TRUE,ReadComplete=FALSE;

    if (hDIB) (*hDIB)=NULL;

    // open the input file
    if (input==TER_FILE) { // data in the file
       lstrupr(InFile);
       rTrim(InFile); // trim any spaces on right
       if (lstrlen(InFile)==0) return FALSE;
       lstrcpy(TempString,InFile); // make a copy in the data
segment
       if
(HFILE_ERROR==(hFile=OpenFile(TempString,&OpenBuf,OF_READ)))
          return PrintError(w,MSG_ERR_FILE_OPEN,"Jpg2Bmp");
    }
    else { // lock the buffer
       if (NULL==(InBuf=GlobalLock(hBuf))) return
PrintError(w,MSG_ERR_MEM_LOCK,"Jpg2Bmp");
    }

    // allocate space for the jpg info structure
    if (NULL==(jpg=(struct StrJpg far *)OurAlloc(sizeof(struct
StrJpg)))) {
       if (input==TER_FILE) _lclose(hFile);
       return PrintError(w,MSG_OUT_OF_MEM,"Jpg2Bmp");
    }
    FarMemSet(jpg,0,sizeof(struct StrJpg)); // initialize with zeros
    jpg->w=w; // store our pointer

    if (input==TER_FILE) jpg->hFile=hFile;
    else {
       jpg->buf=InBuf;
       jpg->BufLen=BufLen;
       jpg->hFile=HFILE_ERROR;
    }

    // Read Start-of-Image
    if (!JpgGetMarker(w,jpg,&marker)) goto END_FILE;

    if (import && marker!=0xD8) return
PrintError(w,MSG_BAD_JPG_FILE,"Jpg2Bmp");
    IsJpgFile=(marker==0xD8);
    if (!import) {
       ReadComplete=TRUE;
       goto END_FILE;
    }

    NEXT_MARKER:
    if (!JpgGetMarker(w,jpg,&marker)) goto END_FILE; // get next
marker

    if (marker==0xD9) { // end of file marker
        ReadComplete=TRUE;
        goto END_FILE;
    }
    else if (marker==0xDB) { // get the quantization
table
       if (!JpgGetQTable(w,jpg)) goto END_FILE;
    }
    else if (marker==0xC0) { // get the image
information (SOF)
       if (!JpgGetImageInfo(w,jpg)) goto END_FILE;
    }
    else if (marker==0xC1) goto END_FILE; // Extended sequential DCT
frame not supported
    else if (marker==0xC2) goto END_FILE; // Progressive DCT frame
not supported
    else if (marker==0xC3) goto END_FILE; // Lossless DCT frame not
supported
    else if (marker==0xC4) { // Huffman table
       if (!JpgGetHuffTable(w,jpg)) goto END_FILE;
    }
    else if (marker==0xDD) { // Restart interval
       if (!JpgGetWord(w,jpg)) goto END_FILE; // pass over the segment
length
       if (!JpgGetWord(w,jpg)) goto END_FILE; // retrieve restart
interval
       jpg->McuPerInterval=jpg->CurWord;
    }
    else if (marker==0xDA) { // image data
       if (!JpgReadImage(w,jpg)) goto END_FILE;
    }
    else JpgSkipMarker(w,jpg); // skip over the current marker

    goto NEXT_MARKER;

    END_FILE:
    // pass the DIB handle
    GlobalUnlock(jpg->hDIB);
    if (hDIB==NULL || !IsJpgFile || !ReadComplete) {
       GlobalFree(jpg->hDIB);
       jpg->hDIB=NULL;
    }
    if (hDIB) (*hDIB)=jpg->hDIB;

    // close file and release buffers
    if (input==TER_FILE) _lclose(jpg->hFile);

    // release memory
    for (i=0;i<jpg->HuffTblCount;i++) {
       if (jpg->HuffTbl[i].pSymbol) OurFree(jpg->HuffTbl[i].pSymbol);
       if (jpg->HuffTbl[i].pSymLen) OurFree(jpg->HuffTbl[i].pSymLen);
       if (jpg->HuffTbl[i].pCode) OurFree(jpg->HuffTbl[i].pCode);
    }
    OurFree(jpg);

    if (ReadComplete) {
       if (import) return (BOOL)(*hDIB);
       else return IsJpgFile;
    }
    else return FALSE;
}