TalkPHP - Simple pixelate + negative functions

So over the last few months I've developed a few helper functions for some image related stuff I've been working on using PHP and GD and thought I would share them...

The filters simply introduces a function to pixelate an image resource and the second one makes all colors negative just like the imagefilter($im, IMG_FILTER_NEGATE) function, however since this is written in PHP theres really a difference in using my version and the C version, so use that if possible.

Sources:

PHP Code:


		
			
<?php

    function imagepixelate($im, $blocksize)

    {

        $blocksize = (int) $blocksize;



        if($blocksize < 0)

        {

            return(false);

        }



        if($blocksize == 1)

        {

            return(true);

        }



        for($x = 0; $x < imagesx($im); $x += $blocksize)

        {

            for($y = 0; $y < imagesy($im); $y += $blocksize)

            {

                if(!@ImageFilledRectangle($im, $x, $y, ($x + $blocksize - 1), ($y + $blocksize -1), ImageColorAt($im, $x, $y)))

                {

                    return(false);

                }

            }

        }



        return(true);

    }



    function imagenegate($im)

    {

        for($x = 0; $x < imagesx($im); ++$x)

        {

            for($y = 0; $y < imagesy($im); ++$y)

            {

                $rgb = imagecolorat($im, $x, $y);



                imagesetpixel($im, $x, $y, imagecolorallocate($im, (255 - (($rgb >> 16) & 0xFF)), (255 - (($rgb >> 8) & 0xFF)), (255 -($rgb & 0xFF))));

            }

        }



        return(true);

    }

?>

Note that I removed my checks for valid resource streams as these were apart of a smaller framework/package, so be sure to pass a valid image stream to them.

Prototypes:
bool imagepixelate( resource $im, integer $blocksize )
Pixelates an image

$im - A valid resource to a GD image
$blocksize - How many pixels that should go on each block, 1 = no effect because 1 = 1 pixel

bool imagenegate( resource $im )
Reverses color and creates a negative effect

$im - A valid resource to a GD image

Cheers, hope this will help someone ;)