I37B Answer ― Image Doubling

/* Double Images */
void doubleImage( image full, image *twice )
{
  int r, c, p ;

  /* construct an image structure of the appropriate size */
  if ( !newImage( twice, full.nrows*2, full.ncols*2 ) )
  {
    printf("doubleImages(): newImage() failed\n" );
    exit( EXIT_FAILURE );
  }

  for ( r=0; r<full.nrows; r++ )
    for ( c=0; c<full.ncols; c++ )
    {
      p = getPixel( full, r, c ) ;
      setPixel( *twice, r*2,   c*2,   (unsigned char)p );
      setPixel( *twice, r*2,   c*2+1, (unsigned char)p );
      setPixel( *twice, r*2+1, c*2,   (unsigned char)p );
      setPixel( *twice, r*2+1, c*2+1, (unsigned char)p );
    }
}

Comments: