Convert 24 bit BMP image to halftone BMP image

     #include"stdio.h"
     #include"stdafx.h"
     void con(unsigned char x)
     {
	char a;
	int j;
	FILE *f1;
	f1=fopen("image_24_bit.txt","a");

	for(j=0;j<=7;j++)
	{
		a=(x<<j & 1<<7)?1:0;
		printf("%d",a);
		fprintf(f1,"%d",a);
	}
	
	fclose(f1);
	printf("\n");
        }

        void main()
        {
	FILE *f;
	long int i=0;
        unsigned char c;
	f=fopen("sample.bmp","rb");
	for(i=1;i<=54;i++)
	{
	fread(&c,sizeof(c),1,f);
	}
	for(i=55;i<=177560;i++)
	{
        fread(&c,sizeof(c),1,f);
	con(c);
	}
	fclose(f);
        }

       module read(dataout,htpv);
       output reg [0:1420479]dataout;
       output reg [1:59186]htpv;
       reg [24:1]error[59186:0];
       reg [25:0]cpv,cpv_round,e_av;
       reg [0:1420479]data[0:0]; 
       reg [1:24]data_out;
       parameter threshold =8388608,w1=2,w2=8,w3=4,w4=2;
       integer i=0,f1;
       initial 
        begin
          $readmemb("image_24_bit.txt",data); 
          dataout=data[0];
        end
       initial
        begin
         error[0]=24'b0;
         f1=$fopen("HTPimage.bmp","a");
         for(i=0;i<306;i=i+1)
        begin
         data_out=dataout[(i*24)+:24];
         e_av=(w1*error[i])>>4;
         cpv= data_out + e_av;
         cpv_round=(cpv<threshold)?0:16777215;
         htpv[i+1]=(cpv_round==0)?0:1;
         error[i+1]=cpv-cpv_round;
       if(htpv[i]==1)
         begin
          $fwrite(f1,"1");
         end
      else
        begin
          $fwrite(f1,"0");
        end
       #1;
       end
      for(i=306;i<591886;i=i+1)
       begin
         data_out=dataout[(i*24)+:24];
         e_av=(2*error[i]+8*error[i-306]+4*error[i-305]+2*error[i-304])>>4;
         cpv= data_out + e_av;
        cpv_round=(cpv<threshold)?0:16777215;
        htpv[i+1]=(cpv_round==0)?0:1;
        error[i+1]=cpv-cpv_round;
       if(htpv[i]==1)
         begin
        $fwrite(f1,"1");
        end
       else
       begin
        $fwrite(f1,"0");
       end
       #1;
       end
       $fclose(f1);
      end
       endmodule