imagecolorat
  (PHP 4, PHP 5)
imagecolorat — Get the index of the color of a pixel
  
 
  Description
  
   int imagecolorat
    ( resource $image
   , int $x
   , int $y
   )
  
  
   If PHP is compiled against GD library 2.0 or higher and the image is a
   truecolor image, this function returns the RGB value of that pixel as
   integer. Use bitshifting and masking to access the distinct red, green and blue
   component values:
  
  
 
  Parameters
  
   
    - 
image
 - 
An image resource, returned by one of the image creation functions, 
such as imagecreatetruecolor().
 
    - 
     x
     
 - 
      
       x-coordinate of the point.
      
      
    
    - 
     y
     
 - 
      
       y-coordinate of the point.
      
      
    
   
  
  
 
  Return Values
  
   Returns the index of the color.
  
  
 
  Examples
  
   
    Example #1 Access distinct RGB values
    
<?php
$im = imagecreatefrompng("php.png");
$rgb = imagecolorat($im, 10, 15);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
?>
     
    The above example will output 
something similar to:
 
    
int(119)
int(123)
int(180)