compare_coordinates.php

/*
@params

$center_x: returned by Coyote (is the percentage of photo width)
$center_y: returned by Coyote (is the percentage of photo height)
$thresh: threshold value for matching (currently set to 0.030)
$pwidth: width of the photo
$pheight: height of the photo
*/

function compare_cordinates($image_name,$tids,$center_x,$center_y,$thresh,$pwidth,$pheight){
	
  /* Find new coordinates in the x-axis ($x_lower and $x_upper) which is at the threshold pixels to the right and left of the $center_x.
  */
  $x_lower=($center_x*$pwidth/100)-($pwidth*$thresh); 
  $x_upper=($center_x*$pwidth/100)+($pwidth*$thresh); 

  /* Find new coordinates in the y-axis ($y_lower and $y_upper) which is at the threshold pixels at the top and bottom of the $center_y.
  */
  $y_lower=($pheight-($center_y*$pheight/100))-($pheight*$thresh); 
  $y_upper=($pheight-($center_y*$pheight/100))+($pheight*$thresh); 
          
  // uid_x and uid_y are the coordinates from the iOS app stored in the DB.
  
  /* Update the user tid in the database (match the coordinates from Coyote and iOS app) if the uid_x and uid_y falls in between the calculated threshold coordinates.*/

  $iQuery = "update train_user_app set tid='".$tids."' where image_name='".$image_name."' and uid_x between '".$x_lower."' and '".$x_upper."' and uid_y between '".$y_lower."' and '".$y_upper."'";
  $iResult = mysql_query( $iQuery);
          
}