/*******************/
	xc_cal = CAL_x_center[ch_no-1];
	yc_cal = CAL_y_center[ch_no-1];
	r0_cal = CAL_width_image[ch_no-1]/2;

	irmax = 2*r_image;

  /** data file open **/
	sprintf(fin_name,"%s/work2/tmp/%s-%07d.jpg",base_dir,header_name,k);
  	sprintf(cmnd,"jpegtopnm %s > %s/work2/jpgdata.pnm",fin_name,base_dir);
	system(cmnd);
	sprintf(fin_name,"%s/work2/jpgdata.pnm",base_dir);
	f_in = fopen(fin_name,"rb");

  /** read information of the image **/
  	fgets(cdat1,sizeof(cdat1),f_in);
	if(cdat1[1]=='6'){
		fclose(f_in);
  		sprintf(cmnd,"ppmtopgm %s/work2/jpgdata.pnm > %s/work2/jpgdata.pgm",base_dir,base_dir);
		system(cmnd);
		sprintf(fin_name,"%s/work2/jpgdata.pgm",base_dir);
		f_in = fopen(fin_name,"rb");
  		fgets(cdat1,sizeof(cdat1),f_in);
	};

 	fgets(cdat1,sizeof(cdat1),f_in);
	sscanf(cdat1,"%s %s\n",cw,ch);
	width = atoi(cw);
	height = atoi(ch);

  /** read data **/
	n = fread(buf1,nbyte,width*height,f_in);
	ix = 20; iy = height/2;
	bg_obs = buf1[iy*width + ix];

 /** calculate intensity (Rayleigh) from raw data (bit) using CAL data **/
	for(i=0;i<height;i++){
 	for(j=0;j<width;j++){
		a_obs = buf1[i*width + j];
	    dx = j - x_center;
        dy = y_center - i;
		r  = sqrt(dx*dx + dy*dy);
        tet = atan2(dx,dy);

		if(r<=r_image){
			r_cal = r*r0_cal/r_image;
			j_cal = r_cal*sin(tet) + xc_cal;
			i_cal = yc_cal - r_cal*cos(tet);

			if((i_cal>=0 && i_cal<height) && (j_cal>=0 && j_cal<width) && CAL_AA[ch_no-1][i_cal][j_cal]!=0.0){
				Robs = (a_obs - bg_obs)/CAL_AA[ch_no-1][i_cal][j_cal];
			}else{
				Robs = 0.0;
			};
		}else{
			Robs = 0.0;
		};
	
		if(ch_no<=2){
			Robs = Robs/CAL_T[ch_no-1];  /** (kR) **/
		}else{
			Robs = Robs/CAL_EW[ch_no-1]*1000.0;  /** (R/nm) **/
		};
		obs_R[ch_no-1][i][j] = Robs;
	}};
}