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<?php
class GDMagic {
var $handle;
var $height;
var $width;
function __construct(&$handle){
$this->handle = $handle;
$this->height = imagesy($handle);
$this->width = imagesx($handle);
}
private function color($x, $y, $color){
$rgb = imagecolorat($this->handle, $x, $y);
Switch($color){
case 0: return ($rgb >> 16) & 0xFF;
break;
case 1: return ($rgb >> 8) & 0xFF;
break;
case 2: return $rgb & 0xFF;
break;
}
}
function gradient($start, $end, $dir='horizontal'){
$opt = (($dir=='vertical')?$this->height:$this->width);
$r = $start[0];
$g = $start[1];
$b = $start[2];
for($i=0;$i<$opt;$i++){
$x1 = (($dir=='vertical')?0:$i);
$y1 = (($dir=='vertical')?$i:0);
$x2 = (($dir=='vertical')?$this->width:$i);
$y2 = (($dir=='vertical')?$i:$this->height);
$color = imagecolorallocate($this->handle, abs($r), abs($g), abs($b));
imageline($this->handle, $x1, $y1, $x2, $y2, $color);
$r -= ($start[0]-$end[0])/$opt;
$g -= ($start[1]-$end[1])/$opt;
$b -= ($start[2]-$end[2])/$opt;
}
return true;
}
function replacecolor($search, $replace, $precision=30, $alpha=0){
for($i=0; $i<$this->width; $i++){
for($j=0; $j<$this->height; $j++){
$r = $this->color($i, $j, 0);
$g = $this->color($i, $j, 1);
$b = $this->color($i, $j, 2);
if( abs($search[0]-$r)<$precision &&
abs($search[1]-$g)<$precision &&
abs($search[2]-$b)<$precision)
{$r=$replace[0]; $g=$replace[1]; $b=$replace[2];}
$color = imagecolorallocatealpha($this->handle, $r, $g, $b, $alpha);
imagesetpixel($this->handle, $i, $j, $color);
}
}
return true;
}
function greyscale(){
for($i=0; $i<$this->width; $i++){
for($j=0; $j<$this->height; $j++){
$r = $this->color($i, $j, 0);
$g = $this->color($i, $j, 1);
$b = $this->color($i, $j, 2);
$gray = ($r+$g+$b)/3;
$color = imagecolorallocate($this->handle, $gray, $gray, $gray);
imagesetpixel($this->handle, $i, $j, $color);
}
}
}
function negative(){
for($i=0; $i<$this->width; $i++){
for($j=0; $j<$this->height; $j++){
$r = $this->color($i, $j, 0);
$g = $this->color($i, $j, 1);
$b = $this->color($i, $j, 2);
$color = imagecolorallocate($this->handle, 255-$r, 255-$g, 255-$b);
imagesetpixel($this->handle, $i, $j, $color);
}
}
}
function blur(){
$matrix = array(array(1,1,1),
array(1,1,1),
array(1,1,1));
$this->convolution_matrix($matrix);
}
function edge(){
$matrix = array(array(0,1,0),
array(1,-4,1),
array(0,1,0));
$this->convolution_matrix($matrix);
}
function emboss(){
$matrix = array(array(-2,-1,0),
array(-1,1,1),
array(0,1,2));
$this->convolution_matrix($matrix);
}
//Beta...
function convolution_matrix($matrix){
$tmp = imagecreatetruecolor($this->width, $this->height);
for($x=0; $x<$this->width; $x++){
for($y=0; $y<$this->height; $y++){
$r[] = $this->color($x-1,$y-1,0)*$matrix[0][0]+
$this->color($x,$y-1,0)*$matrix[1][0]+
$this->color($x+1,$y-1,0)*$matrix[2][0]+
$this->color($x-1,$y,0)*$matrix[0][1]+
$this->color($x,$y,0)*$matrix[1][1]+
$this->color($x+1,$y,0)*$matrix[2][1]+
$this->color($x-1,$y+1,0)*$matrix[0][2]+
$this->color($x,$y+1,0)*$matrix[1][2]+
$this->color($x+1,$y+1,0)*$matrix[2][2];
$g[] = $this->color($x-1,$y-1,1)*$matrix[0][0]+
$this->color($x,$y-1,1)*$matrix[1][0]+
$this->color($x+1,$y-1,1)*$matrix[2][0]+
$this->color($x-1,$y,1)*$matrix[0][1]+
$this->color($x,$y,1)*$matrix[1][1]+
$this->color($x+1,$y,1)*$matrix[2][1]+
$this->color($x-1,$y+1,1)*$matrix[0][2]+
$this->color($x,$y+1,1)*$matrix[1][2]+
$this->color($x+1,$y+1,1)*$matrix[2][2];
$b[] = $this->color($x-1,$y-1,2)*$matrix[0][0]+
$this->color($x,$y-1,2)*$matrix[1][0]+
$this->color($x+1,$y-1,2)*$matrix[2][0]+
$this->color($x-1,$y,2)*$matrix[0][1]+
$this->color($x,$y,2)*$matrix[1][1]+
$this->color($x+1,$y,2)*$matrix[2][1]+
$this->color($x-1,$y+1,2)*$matrix[0][2]+
$this->color($x,$y+1,2)*$matrix[1][2]+
$this->color($x+1,$y+1,2)*$matrix[2][2];
}
}
$maxr = max($r);
$maxg = max($g);
$maxb = max($b);
for($i=0,$x=0; $x<$this->width; $x++){
for($y=0; $y<$this->height; $i++,$y++){
$rt = 255*$r[$i]/$maxr;
$gt = 255*$g[$i]/$maxg;
$bt = 255*$b[$i]/$maxb;
$rc = $rt>0?$rt:0;
$gc = $gt>0?$gt:0;
$bc = $bt>0?$bt:0;
$c = imagecolorallocate($tmp, $rc, $gc, $bc);
imagesetpixel($tmp, $x, $y, $c);
}
}
for($x=0; $x<$this->width; $x++){
for($y=0; $y<$this->height; $y++){
$rgb = imagecolorat($tmp, $x, $y);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
$c = imagecolorallocate($this->handle, $r, $g, $b);
imagesetpixel($this->handle, $x, $y, $c);
}
}
}
}
?>
Some example using the php logo:
Blur:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatefrompng('http://www.php.net/images/logos/php-med-trans.png');
$gdmagic = new GDMagic($img);
$gdmagic->blur();
imagepng($img);
imagedestroy($img);
?>
Edge:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatefrompng('http://www.php.net/images/logos/php-med-trans.png');
$gdmagic = new GDMagic($img);
$gdmagic->edge();
imagepng($img);
imagedestroy($img);
?>
Greyscale:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatetruecolor(500,100);
$gdmagic = new GDMagic($img);
$gdmagic->gradient(array(255,0,0),array(255,255,0));
imagepng($img);
imagedestroy($img);
?>
Negative:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatefrompng('http://www.php.net/images/logos/php-med-trans.png');
$gdmagic = new GDMagic($img);
$gdmagic->negative();
imagepng($img);
imagedestroy($img);
?>
Replace color:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatefrompng('http://www.php.net/images/logos/php-med-trans.png');
$gdmagic = new GDMagic($img);
$gdmagic->replacecolor(array(0,0,0),array(255,0,0));
imagepng($img);
imagedestroy($img);
?>
Verical gradient:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatetruecolor(500,100);
$gdmagic = new GDMagic($img);
$gdmagic->gradient(array(255,0,0),array(255,255,0),'vertical');
imagepng($img);
imagedestroy($img);
?>
Horizontal Gradient:
<?php
header('Content-Type: image/png');
include('GDMagic.php');
$img = imagecreatetruecolor(500,100);
$gdmagic = new GDMagic($img);
$gdmagic->gradient(array(255,0,0),array(255,255,0));
imagepng($img);
imagedestroy($img);
?>
The class is candidate to win the innovation award of January 2009 on phpclasses.
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