source: liacs/MIR2010/SourceCode/cximage/ximajbg.cpp@ 168

/*
 * File:        ximajbg.cpp
 * Purpose:     Platform Independent JBG Image Class Loader and Writer
 * 18/Aug/2002 Davide Pizzolato - www.xdp.it
 * CxImage version 6.0.0 02/Feb/2008
 */

#include "ximajbg.h"

#if CXIMAGE_SUPPORT_JBG

#include "ximaiter.h"

#define JBIG_BUFSIZE 8192

////////////////////////////////////////////////////////////////////////////////
#if CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
bool CxImageJBG::Decode(CxFile *hFile)
{
        if (hFile == NULL) return false;

        struct jbg_dec_state jbig_state;
        unsigned long xmax = 4294967295UL, ymax = 4294967295UL;
        unsigned int len, cnt;
        BYTE *buffer,*p;
        int result;

  cx_try
  {
        jbg_dec_init(&jbig_state);
        jbg_dec_maxsize(&jbig_state, xmax, ymax);

        buffer = (BYTE*)malloc(JBIG_BUFSIZE);
        if (!buffer) cx_throw("Sorry, not enough memory available!");

        result = JBG_EAGAIN;
        do {
                len = hFile->Read(buffer, 1, JBIG_BUFSIZE);
                if (!len) break;
                cnt = 0;
                p = buffer;
                while (len > 0 && (result == JBG_EAGAIN || result == JBG_EOK)) {
                        result = jbg_dec_in(&jbig_state, p, len, &cnt);
                        p += cnt;
                        len -= cnt;
                }
        } while (result == JBG_EAGAIN || result == JBG_EOK);

        if (hFile->Error())
                cx_throw("Problem while reading input file");
        if (result != JBG_EOK && result != JBG_EOK_INTR)
                cx_throw("Problem with input file"); 

        int w, h, bpp, planes, ew;

        w = jbg_dec_getwidth(&jbig_state);
        h = jbg_dec_getheight(&jbig_state);
        planes = jbg_dec_getplanes(&jbig_state);
        bpp = (planes+7)>>3;
        ew = (w + 7)>>3;

        if (info.nEscape == -1){
                head.biWidth = w;
                head.biHeight= h;
                info.dwType = CXIMAGE_FORMAT_JBG;
                cx_throw("output dimensions returned");
        }

        switch (planes){
        case 1:
                {
                        BYTE* binary_image = jbg_dec_getimage(&jbig_state, 0);

                        if (!Create(w,h,1,CXIMAGE_FORMAT_JBG))
                                cx_throw("");

                        SetPaletteColor(0,255,255,255);
                        SetPaletteColor(1,0,0,0);

                        CImageIterator iter(this);
                        iter.Upset();
                        for (int i=0;i<h;i++){
                                iter.SetRow(binary_image+i*ew,ew);
                                iter.PrevRow();
                        }

                        break;
                }
        default:
                cx_throw("cannot decode images with more than 1 plane");
        }

        jbg_dec_free(&jbig_state);
        free(buffer);

  } cx_catch {
        jbg_dec_free(&jbig_state);
        if (buffer) free(buffer);
        if (strcmp(message,"")) strncpy(info.szLastError,message,255);
        if (info.nEscape == -1 && info.dwType == CXIMAGE_FORMAT_JBG) return true;
        return false;
  }
        return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif //CXIMAGE_SUPPORT_DECODE
////////////////////////////////////////////////////////////////////////////////
bool CxImageJBG::Encode(CxFile * hFile)
{
        if (EncodeSafeCheck(hFile)) return false;

        if (head.biBitCount != 1){
                strcpy(info.szLastError,"JBG can save only 1-bpp images");
                return false;
        }

        int w, h, bpp, planes, ew, i, j, x, y;

        w = head.biWidth;
        h = head.biHeight;
        planes = 1;
        bpp = (planes+7)>>3;
        ew = (w + 7)>>3;

        BYTE mask;
        RGBQUAD *rgb = GetPalette();
        if (CompareColors(&rgb[0],&rgb[1])<0) mask=255; else mask=0;

        BYTE *buffer = (BYTE*)malloc(ew*h*2);
        if (!buffer) {
                strcpy(info.szLastError,"Sorry, not enough memory available!");
                return false;
        }

        for (y=0; y<h; y++){
                i= y*ew;
                j= (h-y-1)*info.dwEffWidth;
                for (x=0; x<ew; x++){
                        buffer[i + x]=info.pImage[j + x]^mask;
                }
        }

        struct jbg_enc_state jbig_state;
        jbg_enc_init(&jbig_state, w, h, planes, &buffer, jbig_data_out, hFile);

    //jbg_enc_layers(&jbig_state, 2);
    //jbg_enc_lrlmax(&jbig_state, 800, 600);

        // Specify a few other options (each is ignored if negative)
        int dl = -1, dh = -1, d = -1, l0 = -1, mx = -1;
        int options = JBG_TPDON | JBG_TPBON | JBG_DPON;
        int order = JBG_ILEAVE | JBG_SMID;
        jbg_enc_lrange(&jbig_state, dl, dh);
        jbg_enc_options(&jbig_state, order, options, l0, mx, -1);

        // now encode everything and send it to data_out()
        jbg_enc_out(&jbig_state);

        // give encoder a chance to free its temporary data structures
        jbg_enc_free(&jbig_state);

        free(buffer);

        if (hFile->Error()){
                strcpy(info.szLastError,"Problem while writing JBG file");
                return false;
        }

        return true;
}
////////////////////////////////////////////////////////////////////////////////
#endif  // CXIMAGE_SUPPORT_JBG