From: Barry Treahy, Jr. [Treahy@mmaz.com]
Sent: Tuesday, February 19, 2002 11:18 AM
To: Info-VAX@Mvb.Saic.Com
Subject: Re: Sixel-to-PLC5 - Almost, how about Sixel to Postscript

I did come across a Sixel to Postscript convertor which almost gets you 
there since a lot of HP printers support postscript...

http://www.agh.cc.kcl.ac.uk/files/vms/oldpds/index.txt and the soures 
are pasted below...

Regards,

Barry

/* 6-OCT-88 George Carrette
   [Note: Unsupported, Public Domain]
 
   This work was supported by Mitech Corporation. 74 Junction Square.
   Concord MA. 01742. (508)-371-2002.
 
   Convert a sixel bitmap file into a post-script file, suitable for including
   into Tex documents. The file may also be printed stand-alone.
 
   The arguments are
   $ sixelps <infile> <outfile> [dpi] [xsize ysize]
 
   Where dpi is the number of dots per inch (default 300) of the bitmap
   on output. The xsize and ysize may be given to select a subset of the
   bitmap.
 
   On a VAXSTATION the workstation "printer setup" should specify an aspect
   ratio of 1 to 1 and a "ribbon or toner saver" setup of positive image.
   A color display setup with display background of white or gray generally
   gives the best results when making screen printouts.
 
*/
 
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
 
void convert_sixel_file();
void prescan_sixel_file();
void write_ps_program();
 
main(argc,argv)
 int argc; char **argv;
{FILE *fi,*fo;
 int xsize, ysize,dpi;
 char truename[512];
 if (!((argc == 3) || (argc == 4) || (argc == 6)))
   {fprintf(stderr,"sixelps <infile> <outfile> [dpi] [xsize ysize]\n");
    exit(1);}
 if (!(fi = fopen(argv[1],"rb")))
   {perror(argv[1]);exit(vaxc$errno);}
 if (!(fo = fopen(argv[2],"w"
          /* ,"ctx=rec","mrs=512","rat=cr","rfm=var" */
          )))
   {perror(argv[2]);exit(vaxc$errno);}
 if (fgetname(fi,truename))
   printf("Converting sixel file \"%s\"\n",truename);
 if (fgetname(fo,truename))
   printf("Into postscript file \"%s\"\n",truename);
 if (argc >= 4) dpi = atol(argv[3]); else dpi = 300;
 printf("with %d dots per inch resolution\n",dpi);
 if (argc == 6)
   {xsize = atol(argv[4]);
    ysize = atol(argv[5]);}
 else
   {prescan_sixel_file(&xsize,&ysize,fi);
    fclose(fi);
    if (!(fi = fopen(argv[1],"rb")))
      {perror(argv[1]);exit(vaxc$errno);}}
 if (xsize & 7) xsize = xsize + (8 - (xsize & 7));
 printf("xsize = %d, ysize = %d\n",xsize,ysize);
 write_ps_program(xsize,ysize,dpi,fo);
 convert_sixel_file(xsize,ysize,fi,fo);
 fprintf(fo,"\n\n%%end(plot)\n\n");
 fprintf(fo,"%% the showpage should be ignored when inserting\n");
 fprintf(fo,"%% into a larger document\n");
 fprintf(fo,"showpage\n");
 fclose(fo);}
 
#define PS_LLX 36
#define PS_LLY 36
 
void write_ps_program(xsize,ysize,dpi,f)
     int xsize,ysize; FILE *f;
{int xsizeu,ysizeu;
 xsizeu = (xsize*72)/dpi;
 ysizeu = (ysize*72)/dpi;
 fprintf(f,
     "%%%%BoundingBox: %d %d %d %d\n%%plot follows\n",
     /* llx lly urx ury */
     PS_LLX,PS_LLY,PS_LLX+xsizeu,PS_LLY+ysizeu);
 fprintf(f,"%%begin(plot)\n");
 fprintf(f,"%% bitmap image converted from sixel format follows.\n");
 fprintf(f,"%% intended to be inserted into a document\n");
 fprintf(f,"%% with a program which includes only those commands inside\n");
 fprintf(f,"%% the begin(plot) and end(plot) statements\n");
 fprintf(f,"%d %d translate\n",PS_LLX,PS_LLY);
 fprintf(f,"/picstr 1 string def\n");
 fprintf(f,"%d %d scale\n",xsizeu,ysizeu);
 fprintf(f,"%d %d 1 \n",
     xsize,ysize);
 fprintf(f,"[%d 0 0 -%d 0 %d]\n",
      xsize,ysize,ysize);
 fprintf(f,"{currentfile picstr readhexstring pop} image\n");
}
 
 
#define CH_ESC (27)
 
skip_sixel_header(f)
     FILE *f;
{int c;
 c = getc(f);
 if (c != CH_ESC) ch_err("first character is 0%o, expecting 0%o\n",c,CH_ESC);
 c = getc(f);
 if (c != 'P') ch_err("second character is 0%o, expecting 0%o\n",c,'P');
 while ((c = getc(f)) != 'q')
   if (c == EOF) ch_err("got 0%o before 0%o at start of file\n",EOF,'q');}
 
read_decnum(f)
     FILE *f;
{int c,n;
 n = 0;
 while (1)
   {c = getc(f);
    if (c == EOF) ch_err("end of file inside decimal number\n",0,0);
    if ((c < '0') || (c > '9')) {ungetc(c,f); return(n);}
    n = 10*n + (c - '0');}}
 
 void
prescan_sixel_file(px,py,f)
     int *px, *py; FILE *f;
{int max_nx,nx,c,i,fresh_line;
 max_nx = 0;
 *py = 0;
 skip_sixel_header(f);
 nx = 0;
 fresh_line = 1;
 while(1)
   {c = getc(f);
    switch (c)
      {case '!':
     i = read_decnum(f);
     getc(f);
     if (fresh_line)
       {*py = *py + 6;
        if (nx > max_nx) max_nx = nx;
        nx = i;
        fresh_line = 0;}
     else
       nx = nx + i;
     break;
       case '#':
     ch_err("color change character 0%o not handled\n",c,0);
       case '$':
     ch_err("overprint character 0%o not handled\n",c,0);
       case '-':
     fresh_line = 1;
     break;
       case CH_ESC:
     c = getc(f);
     if (c != '\\')
       ch_err("expecting terminator 0%o, but got 0%o\n",'\\',c);
     if (nx > max_nx) max_nx = nx;
     *px = max_nx;
     return;
       default:
     if ((c < 077) || (c > 0176))
       ch_err("got character 0%o, out of sixel range\n",c,0);
     if (fresh_line)
       {*py = *py + 6;
        if (nx > max_nx) max_nx = nx;
        nx = 1;
        fresh_line = 0;}
     else
       nx = nx + 1;}}}
 
char *read_sixel_bitmap();
void write_sixel_bitmap();
 
 void
convert_sixel_file(xsize,ysize,fi,fo)
 int xsize,ysize;
 FILE *fi,*fo;
{char *bits;
 bits = read_sixel_bitmap(xsize,ysize,fi);
 fclose(fi);
 write_sixel_bitmap(xsize,ysize,bits,fo);
 free(bits);}
 
     int
nbits_to_nbytes(x)
     int x;
{return( (x >> 3) + ((x & 7) ? 1 : 0));}
 
 void
write_sixel_bitmap(xsize,ysize,bits,f)
 int xsize,ysize;
 char *bits;
 FILE *f;
{int j,n,c;
 static char hex[] = "0123456789ABCDEF";
 n = nbits_to_nbytes(xsize*ysize);
 printf("%d bytes in hex dump of bitmap\n",n*2);
 for(j=0;j<n;++j)
   {putc(hex[(bits[j] & 0xF0) >> 4],f);
    putc(hex[bits[j] & 0xF],f);
    if ((j % 20) == 19) putc('\n',f);}
 putc('\n',f);}
 
 void
set_sixel(c,x,y,xsize,ysize,bitmap)
     int c,x,y,xsize,ysize;
     char *bitmap;
{int j,yy,bit_index,byte_index,bit_pos,bit;
 if (x >= xsize) return;
 for(j=0;j<6;++j)
   {yy = j + y;
    if (yy >= ysize) return;
    bit = (c>>j) & 1;
    if (!bit) continue;
    bit_index = (yy*xsize) + x;
    byte_index = bit_index >> 3;
    bit_pos = 7 - (bit_index & 7);
    bitmap[byte_index] = bitmap[byte_index] & ~(bit << bit_pos);}}
 
 char *
read_sixel_bitmap(xsize,ysize,f)
 int xsize,ysize;
 FILE *f;
{int x,y,c,i,j;
 char *bitmap;
 bitmap = (char *) malloc(nbits_to_nbytes(xsize*ysize));
 memset(bitmap,255,nbits_to_nbytes(xsize*ysize));
 x = 0;
 y = 0;
 skip_sixel_header(f);
 while(1)
   {c = getc(f);
    switch (c)
      {case '!':
     i = read_decnum(f);
     c = getc(f);
     for(j=0;j<i;++j)
       {set_sixel(c - 077,x,y,xsize,ysize,bitmap);
        ++x;}
     break;
       case '#':
     ch_err("color change character 0%o not handled\n",c,0);
       case '$':
     ch_err("overprint character 0%o not handled\n",c,0);
       case '-':
     x = 0;
     y = y + 6;
     break;
       case CH_ESC:
     c = getc(f);
     if (c != '\\')
       ch_err("expecting terminator 0%o, but got 0%o\n",'\\',c);
     return(bitmap);
       default:
     if ((c < 077) || (c > 0176))
       ch_err("got character 0%o, out of sixel range\n",c,0);
     set_sixel(c - 077,x,y,xsize,ysize,bitmap);
     ++x;}}}
 
 
 
 
ch_err(msg,c1,c2)
     char *msg; int c1,c2;
{fprintf(stderr,msg,c1,c2);
 exit(1);}



Barry Treahy, Jr. wrote:

> If you must create a convertor from scratch, you may want to look at 
> the Unix PBM program and using it as a template might help make your 
> work easierl...
>
> http://www.itc.virginia.edu/research/netpbm.html
>
> Barry
>
>
>
> Jean Paul COMPTOUR wrote:
>
>> Hi All,
>>
>>
>> Does anybody know whether exists a Sixel-to-PLC5 protocol conversion 
>> box or
>> software ?
>>
>> We use Sixel writing directly to a DEC printer connected to a serial 
>> port
>> under VMS 7.1-2
>> and plan to use a market PC printer like HP DeskJet ou Epson.
>>
>> Thanks for any idea.
>>
>> -- 
>> Jean-Paul COMPTOUR
>> jean-paul.comptour@ceric-automation.fr
>> Tel (33)380267187
>> Fax (33)380217534
>>
>>
>>
>

-- 

Barry Treahy, Jr  *  Midwest Microwave  *  Vice President & CIO 

E-mail: Treahy@mmaz.com * Phone: 480/314-1320 * FAX: 480/661-7028