// colorfind.cpp
// Porter's program for cutting out colored squares
// modified by DS 3/8/09
//

static char *usage ="\n  usage: %s in.png cutsquares.png [marked-in.png]\n";

#include "imageLib.h"
#include "math.h"
#define VERBOSE 1

#define ROUND(x) ((x) >= 0? ((int)((x) + .5)) : ((int)((x) - .5)))

//Pulls the colors from the color checker and makes a new image with just the color squares

void colorfind(CByteImage src, CByteImage& dst)
{
  CShape sh = src.Shape();
  int w = sh.width, h = sh.height, nB = sh.nBands;
  int ncols;  //Number of squares ncols the checker
  int nrows;   //number of squares vertically on the checker
  float aspect = (float) w/h;
  float trimfactor;
  float colorfract; // size of color patch as fraction of full square

  //Aspect ratio determines which checker is assumed
  if(aspect > 1.46){ // 24 checker
    ncols = 6;
    nrows = 4;
    trimfactor = .005;
    colorfract = .75;
  }
  else{ // 140 checker
    ncols = 14;
    nrows = 10;
    trimfactor = .002;
    colorfract = .55;
  }
  //Comment on method here

  float xlost = w*trimfactor;
  float s = (w+2*xlost)/ncols ;
  float center = s/2;
  int r = ROUND(colorfract * center);
  if (r < 1) r = 1; // make sure radius doessn't get too small
  int d = 2*r + 1; // diameter, i.e., square size in cropped image
  int firstCenterx = ROUND(center-xlost);
  float ylost = (nrows * s - h) / 2;
  //printf("xlost = %.1f, ylost = %.1f\n", xlost, ylost);
  int firstCentery = ROUND(center-ylost);
 
  //Create a new image shape with the appropriate size

  CShape sh2(d*ncols, d*nrows, nB);
  dst.ReAllocate(sh2);
  //Iterates over each square, and then each pixel in the square, and writes to the new image, and clear the pixel in the source
 
  for(int j = 0; j < nrows; j++){
    for(int i = 0; i < ncols; i++){
      int xCenter = firstCenterx + ROUND(i*s);
      int yCenter = firstCentery + ROUND(j*s);
      for(int y = - r; y <= r;y++){
	for(int x = -r; x <= r; x++){
	  int srcx = xCenter + x;
	  int srcy = yCenter + y;
	  int dstx = i * d + x + r;
	  int dsty = j * d + y + r;
	  for(int b = 0; b < nB; b++){
	    // copy pixel
	    dst.Pixel(dstx, dsty, b) = src.Pixel(srcx, srcy, b); 

	    // draw border
	    if (b < 3 && // don't change alpha channel
		(x == - r || y == - r || x == r || y == r)) {
	      src.Pixel(srcx, srcy, b) = src.Pixel(xCenter, yCenter, b) < 128 ? 255 : 0;
	    } 
	  }
	}
      }
    }
  }   
}

int main(int argc, char *argv[])
{
  try {
      if (argc < 3)
      throw CError(usage, argv[0]);
    
    CByteImage im1, im2;
    ReadImageVerb(im1, argv[1], VERBOSE);
    CShape sh = im1.Shape();

    colorfind(im1, im2);
    
    WriteImageVerb(im2,argv[2], VERBOSE);

    if (argc > 3)
	WriteImageVerb(im1,argv[3], VERBOSE);
  }
  catch (CError &err) {
    fprintf(stderr, err.message);
    fprintf(stderr, "\n");
    return -1;
  }
  
  return 0;
}