📄 pbm2png.c

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/* (c) 2000 Karel Kulhavy, Clocksoft * clock@atrey.karlin.mff.cuni.cz * This program is a stdin filter that performs these operations: * 1) Downconverts 17x15 oversampled binary image data (black-or-white *    pixels, 1 bit per pixel, pbmraw format) to 256-level grayscale *    pgmraw format and saves it to basename_%d.png. * 2) At the end, generates necessary html's * 3) The input pages must be concatenated * 4) Recommended source of the pbm: Aladdin Ghostscript * If there is an input argument (one number as first arg), it's treated * as number of first page that comes at fd #0. Default value is 0. * Parameters: <hundred_dpi> <basename_> <titlestring> <bottom_html_code> * <pageoffset> <input_filename> [first page number] * Little benchmarks:   Normal (gs+pbm2png)     1:32                        Without pbm2png         0:28                        Without libpng          0:51                        Without grayscaling     0:32                         */#include <stdio.h>#include <stdlib.h>#include <string.h>#include <unistd.h>#include <png.h>#include <sys/types.h>#include <sys/stat.h>#include <fcntl.h>#include <errno.h>unsigned char *basename_;/*	basename:		pbm2png.c:32: `basename' redeclared as different kind of symbol		/usr/include/string.h:245: previous declaration of `basename'*/unsigned char *titlestring;unsigned char *bottom;int pageoffset=-13;unsigned long t1[256]; /* Conversion from 1-bit to 2-bit expansion */unsigned long t2[256]; /* Conversion from 2-bit to 4-bit expansion */unsigned char *l1; /* Input data, output data. lw<<1 bytes long */unsigned long *l2; /* 2-bit expansion lw unsigned long's long*/unsigned long long *l4; /* 4-bit expansion lw unsigned long long's long */int ox,oy;int lw; /* Width of the input in 16-pixel units. */int lb; /* Width of the input in 8-pixel units */FILE *of;int filenumber;int x,y;png_structp png_ptr;png_infop info_ptr;unsigned long ppm;float dpi;unsigned char string[8192];unsigned char *filename;int ifd;voidgentables(void){        int a,d;        unsigned long b;        unsigned char c;        for (a=0;a<256;a++){                b=0;                c=a;                for (d=7;d>=0;d--){                        b<<=2;                        b|=(c>>d)&1;                }                t1[a]=b;                b=0;                c=a;                for (d=4;d;d--){                      b<<=4;                      b|=c&3;                      c>>=2;               }                t2[a]=b;        }}voidmake_index(void){	FILE *f;		f=fopen("index.html","w");	fprintf(f,"<html><head><title>%s</title></head><body bgcolor=\"#000000\" text=\"#00ff00\" link=\"#ffff00\""		" vlink=\"#00ffff\" alink=\"#ffff00\">\n",titlestring);	fprintf(f,"<a href=\"../\"><img src=\"up.png\" border=0></a><br>"		"<a href=\"%s.pdf\">Download in PDF format</a><br>"		"<h1>%s</h1><h2>Page index</h2>",basename_,titlestring);	{		int n;		unsigned char *t;		FILE *g;			fprintf(f,"<table cellspacing=0 cellpadding=0 border=1>\n<tr>");		for (n=0;n<filenumber;n++){			if (!(n%40)&&n){				fprintf(f,"</tr>\n<tr>");			}			fprintf(f,"<td><a href=\"%s%d.html\">%d</a></td>\n",basename_,n,n+pageoffset);		}				fprintf(f,"</tr></table><h2>");		g=fopen("index.dir","rb");		if (g)		{				t=malloc(65536);			fprintf(f,"Contents Index</h2><table border=0 cellspacing=0 cellpadding=0>");			while(fgets(t,65536,g)){				int val=0;				int len=strlen(t);				unsigned char *u=t;				if (len&&t[len-1]=='\n') t[len-1]=0;				if (*t>'9'||*t<'0') continue;				while(*u>='0'&&*u<='9'){					val*=10;					val+=*u-'0';					u++;				}					val--;				u++; /* The char behind the number is ignored */				fprintf(f,"<tr><td>%d </td><td><a href=\"%s%d.html\">%s</a></td></tr>\n",val+pageoffset					,basename_,val,u);			}			fprintf(f,"</table>");			fclose(g);			free(t);		}		fprintf(f,"</body></html>");		fclose(f);				}}voidmake_page(int index){ FILE *f;  sprintf(string,"%s%d.html",basename_,index); f=fopen(string,"w"); fprintf(f,"<html><head><title>%s</title></head><body bgcolor=\"#000000\" text=\"#00ff00\" link=\"#ffff00\" vlink=\"#00ffff\"alink=\"#ffff00\">\n",titlestring); fprintf(f,"<h1>%s, Page %d</h1>\n",titlestring,index+pageoffset); fprintf(f,"<p><table border=0 cellspacing=0 cellpadding=2><tr>"); fprintf(f,"<td valign=\"top\"><table border=0 cellpadding=0 cellspacing=0><tr><td>"); if (index) {  fprintf(f,"<a href=\"%s%d.html\"><img src=\"left.png\" border=0></a>\n",basename_,index-1); } else {  fprintf(f,"<img src=\"left.png\" border=0>\n"); } fprintf(f,"</td><td>"); if (index<filenumber-1) {  fprintf(f,"<a href=\"%s%d.html\"><img src=\"right.png\" border=0></a>\n",basename_,index+1); } else {  fprintf(f,"<img src=\"right.png\" border=0>\n"); } fprintf(f,"</td></tr><tr><td colspan=2><a href=\"index.html\"><img src=\"idx.png\" border=0 ></a></td>"); fprintf(f,"</tr></table>"); fprintf(f,"</td><td><img src=\"%s%d.png\" border=\"0\"></td>\n</tr></table>",basename_,index); fprintf(f,"</body></html>"); fclose(f);}/* Returns 0 is OK, exit(1) on error, returns 1 on broken pipe */int sure_read(unsigned char *dest, size_t len){        ssize_t rd;        if (!len) return 0;        again:        rd=read(ifd,dest,len);        if (rd==len) return 0;        if (!rd) return 1;        if (rd<0&&(errno==EINTR||errno==EAGAIN||errno==EWOULDBLOCK)) goto again;        if (rd>0&&rd<len){                /*fprintf(stderr,"read %d/%d",rd,len);*/                len-=rd;                dest+=rd;                fflush(stderr);                goto again;        }        fprintf(stderr,"read error.\n");        perror("");        exit(1);}inteat_up_whitespace_and_comments(void){        again:        sure_read(string,1);        if (*string==' '||*string=='\t'){                goto again;        }        if (*string=='\n'||*string=='\r'){                goto again;        }        if (*string=='#'){                /* Eat up comment */                aa:                sure_read(string,1);                if (*string!='\n'&&*string!='\r') goto aa;                goto again;        }        return *string;}intread_header(void){                /*        if (filenumber)        {                int a;                                for (a=0;a<256;a++){                        sure_read(string,1);                        printf("%d ", *string);                        fflush(stdout);                }                exit(0);         }        */        if (sure_read(string,2)) return 1; /* P1 */        x=eat_up_whitespace_and_comments()-'0';        again:        sure_read(string,1);        if (*string!=' '&&*string!='\t'&&*string!='\n'&&*string!='\r'){                x*=10;                x+=*string-'0';                goto again;        }        y=eat_up_whitespace_and_comments()-'0';        bgain:        sure_read(string,1);        if (*string!=' '&&*string!='\t'&&*string!='\n'&&*string!='\r'){                y*=10;                y+=*string-'0';                goto bgain;        }        return 0;}voidopen_png(void){ png_ptr=png_create_write_struct(PNG_LIBPNG_VER_STRING,NULL,NULL,NULL); info_ptr=png_create_info_struct(png_ptr); png_init_io(png_ptr,of); png_set_filter(png_ptr,0,PNG_FILTER_NONE|PNG_FILTER_SUB|PNG_FILTER_UP  |PNG_FILTER_AVG|PNG_FILTER_PAETH); png_set_compression_level(png_ptr,Z_BEST_COMPRESSION); png_set_IHDR(png_ptr,info_ptr,ox,oy,8,PNG_COLOR_TYPE_GRAY,PNG_INTERLACE_NONE,  PNG_COMPRESSION_TYPE_DEFAULT,PNG_FILTER_TYPE_DEFAULT); png_set_gAMA(png_ptr,info_ptr,1.0); png_set_pHYs(png_ptr,info_ptr,ppm,ppm,PNG_RESOLUTION_METER); png_write_info(png_ptr,info_ptr);}voidclose_png(void){ png_write_end(png_ptr,info_ptr); png_destroy_write_struct(&png_ptr,&info_ptr);}/* Represents the same pixels that are in l2 in l4. */voidmove_2_to_4(void){        unsigned long long bit4;        unsigned long bit2;        int index;                        for (index=lw-1;index>=0;index--){                bit2=l2[index];                bit4=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                l4[index]=bit4;        }}/* Adds the same pixels that are in l2 to l4. */voidadd_2_to_4(void){        unsigned long long bit4;        unsigned long bit2;        int index;                        for (index=lw-1;index>=0;index--){                bit2=l2[index];                bit4=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                bit4<<=16;                bit2>>=8;                bit4|=t2[bit2&255];                l4[index]+=bit4;        }}/* Moves pixels from l1 to l2 with format change */voidmove_1_to_2(void){        int index;                for (index=lw-1;index>=0;index--)                l2[index]=(t1[l1[index<<1]]<<16)|t1[l1[(index<<1)+1]];}/* Adds pixels from l1 to l2 with format change */voidadd_1_to_2(void){        int index;                for (index=lw-1;index>=0;index--)                l2[index]+=(t1[l1[index<<1]]<<16)|t1[l1[(index<<1)+1]];}/* Loads 1 line into l1 */voidload(void){        sure_read(l1,lb);}/* Loads 3 lines into l2 */voidload_to_2(void){        load();        move_1_to_2();        load();        add_1_to_2();        load();        add_1_to_2(); }/* Loads 15 lines into l4 */voidload_to_4(void){        load_to_2();        move_2_to_4();        load_to_2();        add_2_to_4();        load_to_2();        add_2_to_4();        load_to_2();        add_2_to_4();        load_to_2();        add_2_to_4();}/* Converts the data from l4 to l1 including suming up 17 adjacent pixels */voidexport_from_4(void){        int a,b,reg_hold;        unsigned char sum;        unsigned long long *loader=l4;        unsigned long long reg=0;        reg_hold=0;        for (a=0;a<ox;a++){                sum=0;                for (b=17;b;b--){                      if (!reg_hold){                              reg=*loader++;                              reg_hold=16;                      }                      sum+=reg&15;                      reg>>=4;                      reg_hold--;                }                l1[a]=sum;        }        png_write_row(png_ptr,l1);}/* * Parameters: <hundred_dpi> <basename_> <titlestring> <bottom_html_code> * <pageoffset> [first page number] */intmain(int argc, char **argv){        int a,z;         if (argc<7){                fprintf(stderr,"Usage: pbm2png <hundred_dpi> <basename_> <titlestring><bottom_html_code> <pageoffset> <ifname> [starting_filenumber]\n");        return 0;        }        dpi=atof(argv[1])/10;        ppm=dpi*1000/25.4;        basename_=argv[2];        titlestring=argv[3];	bottom=argv[4];        pageoffset=atol(argv[5]);        filename=argv[6];	again0:        ifd=open(filename,O_RDONLY);	if (ifd<0){		if (errno==EAGAIN||errno==EINTR||errno==EWOULDBLOCK) goto			again0;		else {			perror("");			exit(1);		}	}        fprintf(stderr,"filename %s, %d\n",filename,ifd);        if (argc>=8){                filenumber=atol(argv[7]);        }        gentables();        again:        fprintf(stderr,"\nFile %i\n",filenumber);        if (read_header()){                for (a=0;a<filenumber;a++)                        make_page(a);		make_index();                return 0;        }        lw=(x+15)>>4;        lb=(x+7)>>3;        ox=x/17;        oy=y/15;        fprintf(stderr,"Input: %i*%i pixels, %f*%f dpi, %.1fMB.\n",x,y,dpi*17,dpi*15,(float)lb*y/1048576);        fprintf(stderr,"Ouput: %i*%i pixels, %f*%f dpi, %.1fKB raw data.\n",ox,oy,dpi,dpi,(float)ox*oy/1024);        l1=(unsigned char*)malloc(lw*2);        l2=(unsigned long*)malloc(lw*sizeof(unsigned long));        l4=(unsigned long long*)malloc(lw*sizeof(unsigned long long));        sprintf(string,"%s%d.png",basename_,filenumber);        filenumber++;        of=fopen(string,"w");        open_png();        for (z=oy;z;z--){                if (!(z&15)){                        fprintf(stderr,".");                        fflush(stderr);                }                 load_to_4();                export_from_4();        }        close_png();        fprintf(stderr,"\nWritten %lu bytes of data, ratio %.1f%%\n",ftell(of),(float)ftell(of)*100/ox/oy);        fclose(of);        for (a=y%15;a;a--)                load();        free(l1);        free(l2);        free(l4);        goto again;}
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