morph.cpp

/* ====================================================================== 
 * morph.c -  Generate a metamorphosis sequence. 
 * Copyright (C) 1993 by George Wolberg 
 * 
 * Written by: George Wolberg, 1993 
 * Edited by: Joseph Pan, 2013
 * ====================================================================== 
 */

#include "meshwarp.h"
#include "morph.h"
#include "util.h"
#include <iostream>
using namespace std;

/* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 
 * main: 
 * 
 * Main function to collect user parameters and pass them to morph(). 
 */ 
void main(int argc, char **argv) 
{ 
  int nframes;		// number of frames
  string name;		// basename
  imageP I1, I2;	// source and target images
  imageP M1, M2;	// source and target mesh

  // make sure the user invokes this program properly
  if(argc != 7) { 
	  cerr << "Usage: morph src.bw dst.bw src.XY dst.XY frames name\n";
	  exit(1); 
  }

  // read input image and meshes	
  
  I1 = readImage(argv[1], BW);		// source image
  I2 = readImage(argv[2], BW);		// target image
  M1 = readImage(argv[3], MESH);	// source mesh 
  M2 = readImage(argv[4], MESH);	// target mesh 
  
  morph(I1, I2, M1, M2, nframes, name.c_str()); 
} 
  
void morph(const imageP I1, const imageP I2, const imageP M1, const imageP M2, int nframes, const char *basename) 
{ 
  int  i, j, totalI, totalM; 
  double  w1, w2; 
  char  name[20]; 
  uchar *p1, *p2, *p3; 
  float *x1, *y1, *x2, *y2, *x3, *y3; 
  imageP I3, Iw1, Iw2, M3;		

  /* allocate space for tmp images and mesh */ 
  M3  = allocImage(M1->width, M1->height, MESH);	// temp mesh
  Iw1 = allocImage(I1->width, I1->height, BW);		// temp image1
  Iw2 = allocImage(I1->width, I1->height, BW);		// temp image2
  I3  = allocImage(I1->width, I1->height, BW);		// frame combined of Iw1 and temp Iw2

  /* eval total number of points in mesh (totalM) and image (totalI) */
  totalM = M1->width * M1->height;
  totalI = I1->width * I1->height;

  /* copy first frame to basename_000.bw */
  sprintf(name, "%s_000.bw", basename);
  saveImage(I1, name, BW);
  printf("Finished Frame 0\n");

  for(i=1; i<nframes-1; i++) {
    /* M3 <- linearly interpolate between M1 and M2 */
    w2 = (double) i / (nframes-1);
    w1 = 1. - w2;
  
    /* linearly interpolate M3 grid */
    x1 = (float *) M1->ch[0]; y1 = (float *) M1->ch[1]; 
    x2 = (float *) M2->ch[0]; y2 = (float *) M2->ch[1]; 
    x3 = (float *) M3->ch[0]; y3 = (float *) M3->ch[1]; 
    for(j=0; j<totalM; j++) { 
      x3[j] = x1[j]*w1 + x2[j]*w2; 
      y3[j] = y1[j]*w1 + y2[j]*w2; 
    }

    /* warp I1 and I2 according to grid M3 */ 
    meshWarp(I1, M1, M3, Iw1); 
    meshWarp(I2, M2, M3, Iw2);

    /* cross-dissolve warped images Iw1 and Iw2 */  
    p1 = (uchar *) Iw1->ch[0]; 
    p2 = (uchar *) Iw2->ch[0]; 
    p3 = (uchar *) I3->ch[0]; 
    for(j=0; j<totalI; j++) p3[j] = p1[j]*w1 + p2[j]*w2;

    /* save frame into file */ 
    sprintf(name, "%s_%03d.bw", basename, i); 
    saveImage(I3, name, BW); 
    printf("Finished Frame %d\n", i); 
  }

  /* copy last frame to basename_xxx.bw */ 
  sprintf(name, "%s_%03d.bw", basename, i); 
  saveImage(I2, name, BW); 
  printf("Finished Frame %d\n", i);
}