sort segmented point cloud

/*rvi program

band3:
http://aitech.ac.jp/~y-yama/data/rvi/band3.raw.zip
band4:
http://aitech.ac.jp/~y-yama/data/rvi/band4.raw.zip
512*512
unsigned char

made by Yoshiyuki Yamamoto
ver1.0 2004/5/30*/


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>

int main(int argc,char *argv[])
{
    FILE *fpi,*fpo;
        int i,j,height,width; //width:3,
    unsigned char dn1,dn2,dn3;
    unsigned char i_r,i_g,i_b;
    unsigned char *file;
    //float *file3;
    float start,end;

    start=clock();

    if(argc!=5)
    {
        fprintf(stderr,"Usage: %s\n(1)Input_R_READ_filename\n(2)Input_NIR_READ_filename\n(3)width\n(4)height\n",argv[0]);
        exit(1);
    }

        printf("OPEN color list NAME:%s\n",argv[1]);
    printf("OPEN save FILE NAME:\%s\n",argv[2]);
    //printf("OPEN OUTPUT FILE NAME:%s\n",argv[3]);

    width = atoi(argv[3]); printf("W = %d,", width);
        height = atoi(argv[4]); printf("H = %d\n", height);

        file= (unsigned char *)malloc(width*height*sizeof(char));

        if((fpi=fopen(argv[1],"rb"))==NULL)
    {
            fprintf(stderr,"input file open error\n");
        exit(1);
        }

        fread((unsigned char *)file,sizeof(char),width*height,fpi);


        if((fpo=fopen(argv[2],"w"))==NULL)
    {
            fprintf(stderr,"output file open error\n");
        exit(1);
        }

        //fread((float *)file3,sizeof(float),width*height,fpo);

    i_r=file[0];
    i_g=file[1];
    i_b=file[2];

    fprintf(fpo,"%d %d %d\n",i_r,i_g,i_b);

    for(i=0;i<height;i++)
    {
        for(j=0;j<1;j++)
        {
            dn1=file[i*width+j];
            dn2=file[i*width+j+1];
            dn3=file[i*width+j+2];

            if(i_r==dn1 && i_g==dn2 && i_b==dn3)
            {
                printf("same\n");
            }

            else
            {
                i_r=dn1;
                i_g=dn2;
                i_b=dn3;
                fprintf(fpo,"%d %d %d\n",i_r,i_g,i_b);
            }
        }
    }

    free(file);
    //free(file2);
    //free(file3);
    fclose(fpi);
    //fclose(fpi2);
    fclose(fpo);
    end=clock();

    printf("start%fsecond\n",start/1000);
    printf("end%fsecond\n",end/1000);
    printf("duration%f\n",(end-start)/1000);

}