/************************************************************************ * *  snr.c, part of tmn (TMN encoder) * *  Copyright (C) 1997  University of BC, Canada * *  Contacts:  *  Michael Gallant                   <mikeg@ee.ubc.ca> *  Guy Cote                          <guyc@ee.ubc.ca> *  Berna Erol                        <bernae@ee.ubc.ca> * *  UBC Image Processing Laboratory   http://www.ee.ubc.ca/image *  2356 Main Mall                    tel.: +1 604 822 4051 *  Vancouver BC Canada V6T1Z4        fax.: +1 604 822 5949 * *  Copyright (C) 1995, 1996  Telenor R&D, Norway * *  Contacts: *  Robert Danielsen                  <Robert.Danielsen@nta.no> * *  Telenor Research and Development  http://www.nta.no/brukere/DVC/ *  P.O.Box 83                        tel.:   +47 63 84 84 00 *  N-2007 Kjeller, Norway            fax.:   +47 63 81 00 76 * ************************************************************************//* Disclaimer of Warranty *  * These software programs are available to the user without any license fee * or royalty on an "as is" basis. The University of British Columbia * disclaims any and all warranties, whether express, implied, or * statuary, including any implied warranties or merchantability or of * fitness for a particular purpose.  In no event shall the * copyright-holder be liable for any incidental, punitive, or * consequential damages of any kind whatsoever arising from the use of * these programs. *  * This disclaimer of warranty extends to the user of these programs and * user's customers, employees, agents, transferees, successors, and * assigns. *  * The University of British Columbia does not represent or warrant that the * programs furnished hereunder are free of infringement of any * third-party patents. *  * Commercial implementations of H.263, including shareware, are subject to * royalty fees to patent holders.  Many of these patents are general * enough such that they are unavoidable regardless of implementation * design. *  */#include"sim.h"#include<math.h>/********************************************************************** * *	Name:        SNRcomp *	Description:        Compares two image files using SNR *                      No conversion to 422 * *	Input: *	Returns: *	Side effects: * *	Date: 930711	Author: <klillevo@mailbox.jf.intel.com> * ***********************************************************************/void ComputeSNR (PictImage * im1, PictImage * im2, Results * res, int pict_type, int write){  FILE *out = NULL;  int n;  register int m;  int quad, quad_Cr, quad_Cb, diff;  PictImage *diff_image = NULL;  /* Diff. image written to diff_filename */  char *diff_filename = DEF_DIFFILENAME;  if (write)  {    out = fopen (diff_filename, "ab");    diff_image = (PictImage *) malloc (sizeof (PictImage));    diff_image->lum = (unsigned char *) malloc (sizeof (char) * pels * lines);    diff_image->Cr  = (unsigned char *) malloc (sizeof (char) * pels * lines / 4);    diff_image->Cb  = (unsigned char *) malloc (sizeof (char) * pels * lines / 4);  }  quad = 0;  quad_Cr = quad_Cb = 0;  /* Luminance */  quad = 0;  for (n = 0; n < lines; n++)    for (m = 0; m < pels; m++)    {      diff = *(im1->lum + m + n * pels) - *(im2->lum + m + n * pels);      if (write)        *(diff_image->lum + m + n * pels) = 10 * diff + 128;      quad += diff * diff;    }  res->SNR_l = (float) quad / (float) (pels * lines);  if (res->SNR_l)  {    res->SNR_l = (float) (255 * 255) / res->SNR_l;    res->SNR_l = 10 * (float) log10 (res->SNR_l);  } else    res->SNR_l = (float) 99.99;  /* Chrominance */  for (n = 0; n < lines / 2; n++)    for (m = 0; m < pels / 2; m++)    {      quad_Cr += (*(im1->Cr + m + n * pels / 2) - *(im2->Cr + m + n * pels / 2)) *        (*(im1->Cr + m + n * pels / 2) - *(im2->Cr + m + n * pels / 2));      quad_Cb += (*(im1->Cb + m + n * pels / 2) - *(im2->Cb + m + n * pels / 2)) *        (*(im1->Cb + m + n * pels / 2) - *(im2->Cb + m + n * pels / 2));      if (write)      {        *(diff_image->Cr + m + n * pels / 2) =          (*(im1->Cr + m + n * pels / 2) - *(im2->Cr + m + n * pels / 2)) * 10 + 128;        *(diff_image->Cb + m + n * pels / 2) =          (*(im1->Cb + m + n * pels / 2) - *(im2->Cb + m + n * pels / 2)) * 10 + 128;      }    }  res->SNR_Cr = (float) quad_Cr / (float) (pels * lines / 4);  if (res->SNR_Cr)  {    res->SNR_Cr = (float) (255 * 255) / res->SNR_Cr;    res->SNR_Cr = 10 * (float) log10 (res->SNR_Cr);  } else    res->SNR_Cr = (float) 99.99;  res->SNR_Cb = (float) quad_Cb / (float) (pels * lines / 4);  if (res->SNR_Cb)  {    res->SNR_Cb = (float) (255 * 255) / res->SNR_Cb;    res->SNR_Cb = 10 * (float) log10 (res->SNR_Cb);  } else    res->SNR_Cb = (float) 99.99;  if (write)  {    fwrite (diff_image->lum, sizeof (char), pels * lines, out);    fwrite (diff_image->Cr, sizeof (char), pels * lines / 4, out);    fwrite (diff_image->Cb, sizeof (char), pels * lines / 4, out);    free (diff_image->lum);    free (diff_image->Cr);    free (diff_image->Cb);    free (diff_image);    fclose (out);  }  return;}