I42 Answer ― Test Image

#include <stdlib.h>
#include <stdio.h>
#include "basicImage.c"

int main ( int argc, char* argv[] )
{
  image img;
  int r, nrows, c, ncols, N, value ;
  
  if ( argc != 6 )
  {
    printf( "everyNth image rows cols N value\n" );
    system( "pause" );
    exit( EXIT_FAILURE );
  }

  nrows = atoi( argv[2] );
  ncols = atoi( argv[3] );
  N     = atoi( argv[4] );
  value = atoi( argv[5] );

  /* create a blank image */
  newImage( &img, nrows, ncols );

 /* fill in values for the new image */
  for ( r=0; r<img.nrows; r++ )
    for ( c=0; c<img.ncols; c++ )
      if ( c%N == 0 )
        setPixel( img, r, c, (unsigned char) value );
      else
        setPixel( img, r, c, (unsigned char)0 );
        
  /* write the image to disk and free memory */
  writePGMimage( img, argv[1] );
  freeImage( &img );
  
}

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