module main (dout);       output[7:0] dout;       reg   [7:0] dout;       integer   flag,flag1,q0[0:255],q2[0:255],q1 [0:255];       reg   [7:0] mem[0:65535];       integer  i,j,k,m,h,l,q,cnt,fileout;       initial      begin           $readmemb("e:\\twf\\image.dat",mem);           for(j=0;j<=255;j=j+1)              begin                  q0[j]=mem[j];                  q1[j]=mem[j+256];                  q2[j]=mem[j+512];                  flag=1'b1;                  cnt=0;                  $display("memory[%d]=%b",j,mem[j]);              end           for(m=0;m<=253;m=m+1)             begin                     if(flag==1)                 begin                   for (i=2;i<=255;i=i+1)                     begin                       h=(q2[i-2]+2*q2[i-1]+q2[i])-(q0[i-2]+2*q0[i-1]+q0[i]);                       l=(q0[i]+2*q1[i]+q2[i])-(q0[i-2]+2*q1[i-2]+q2[i-2]);                       if (h<0)                        h=0-h;                       if (l<0)                       l=0-l;                       q=h+l;                       if (q>255)                       dout=8'd1;                        else                       dout=8'd0;                        fileout=$fopen("out.txt");                       $fdisplay(fileout,dout);                       if(i==255)                        begin                         flag1=1'b1;                         cnt=cnt+1;                           $fdisplay(fileout,"\n");                           end                     end                 end                    if(flag1==1)                 begin                   for(k=0;k<=255;k=k+1)                      begin                      q0[k]=mem[cnt*256+k];                      q1[k]=mem[(cnt+1)*256+k];                      q2[k]=mem[(cnt+2)*256+k];                      end                   flag1=1'b0;                 end             end        $fclose(fileout);      end    endmodule