This tutorial covers some PHP GD scripts that emulate imagefilter effects without using a filter. These scripts have been collected over the years from the internet, and some are no longer on line. Some come from the new site of Hudzilla but taken from the old site, which is no longer on line. Some of them also have complicated scripting, and functions not covered in these tutorials. You can still use them by adding your url and other parameters needed for the script. Good way to learn.
ORIGINAL BRIGHTNESS Factor 50 Factor -50	Right click, select all, ctrl+c to copy. <?php $image = imagecreatefrompng("images/tandemtruecol-new.png"); $image_width = imagesx($image); $image_height = imagesy($image); $factor = -50; for ($h = 0; $h < $image_height; $h++) { for ($w = 0; $w < $image_width; $w++) { $colors = imagecolorsforindex($image, imagecolorat($image, $w, $h)); $colors['red'] = max(0, min(255, $colors['red'] + $factor)); $colors['green'] = max(0, min(255, $colors['green'] + $factor)); $colors['blue'] = max(0, min(255, $colors['blue'] + $factor)); $new_color = imagecolorallocate($image, $colors['red'], $colors['green'], $colors['blue']); imagesetpixel($image, $w, $h, $new_color); } } header("Content-Type: image/png"); imagepng($image); imagedestroy($image); ?>
PIXELATE Blocksize 6	Right click, select all, ctrl+c to copy. <?php function pixelate(&$image) { $imagex = imagesx($image); $imagey = imagesy($image); $blocksize = 6; for ($x = 0; $x < $imagex; $x += $blocksize) { for ($y = 0; $y < $imagey; $y += $blocksize) { // get the pixel colour at the top-left of the square $thiscol = imagecolorat($image, $x, $y); // set the new red, green, and blue values to 0 $newr = 0; $newg = 0; $newb = 0; // create an empty array for the colours $colours = array(); // cycle through each pixel in the block for ($k = $x; $k < $x + $blocksize; ++$k) { for ($l = $y; $l < $y + $blocksize; ++$l) { // if we are outside the valid bounds of the image, use a //safe colour if ($k < 0) { $colours[] = $thiscol; continue; } if ($k >= $imagex) { $colours[] = $thiscol; continue; } if ($l < 0) { $colours[] = $thiscol; continue; } if ($l >= $imagey) { $colours[] = $thiscol; continue; } // if not outside the image bounds, get colour at this pixel $colours[] = imagecolorat($image, $k, $l); } } // cycle through all the colours we can use for // sampling foreach($colours as $colour) { // add their red, green, and blue values to our master numbers $newr += ($colour >> 16) & 0xFF; $newg += ($colour >> 8) & 0xFF; $newb += $colour & 0xFF; } // now divide the master numbers by the number of valid //samples to get an average $numelements = count($colours); $newr /= $numelements; $newg /= $numelements; $newb /= $numelements; // and use the new numbers as our colour $newcol = imagecolorallocate($image, $newr,$newg, $newb); imagefilledrectangle($image, $x, $y, $x + $blocksize - 1, $y + $blocksize - 1, $newcol); } } } $image = imagecreatefrompng("images/tandemtruecol-new.png"); pixelate($image); header("Content-type: image/png"); imagepng($image); imagedestroy($image); ?>
BLUR at 3	Right click, select all, ctrl+c to copy. <?php //SLOW FUNCTION WON'T TIME OUT WITH THIS set_time_limit(0); function blur (&$image) { $imagex = imagesx($image); $imagey = imagesy($image); //CHANGE NUMBER FOR MORE OR EESS BLUR $dist = 3; for ($x = 0; $x < $imagex; ++$x) { for ($y = 0; $y < $imagey; ++$y) { $newr = 0; $newg = 0; $newb = 0; $colours = array(); $thiscol = imagecolorat($image, $x, $y); for ($k = $x - $dist; $k <= $x + $dist; ++$k) { for ($l = $y - $dist; $l <= $y + $dist; ++$l) { if ($k < 0) { $colours[] = $thiscol; continue; } if ($k >= $imagex) { $colours[] = $thiscol; continue; } if ($l < 0) { $colours[] = $thiscol; continue; } if ($l >= $imagey) { $colours[] = $thiscol; continue; } $colours[] = imagecolorat($image, $k, $l); } } foreach($colours as $colour) { $newr += ($colour >> 16) & 0xFF; $newg += ($colour >> 8) & 0xFF; $newb += $colour & 0xFF; } $numelements = count($colours); $newr /= $numelements; $newg /= $numelements; $newb /= $numelements; $newcol = imagecolorallocate($image, $newr, $newg, $newb); imagesetpixel($image, $x, $y, $newcol); } } } $image = imagecreatefrompng("images/tandemtruecol-new.png"); blur($image); header("Content-type: image/png"); imagepng($image); imagedestroy($image); ?>
SCATTER -2 to 2	Right click, select all, ctrl+c to copy. <?php function scatter(&$image) { $imagex = imagesx($image); $imagey = imagesy($image); for ($x = 0; $x < $imagex; ++$x) { for ($y = 0; $y < $imagey; ++$y) { //CHANGE DISTX, DISTY TO LOWER OR HIGHER $distx = rand(-2, 2); $disty = rand(-2, 2); if ($x + $distx >= $imagex) continue; if ($x + $distx < 0) continue; if ($y + $disty >= $imagey) continue; if ($y + $disty < 0) continue; $oldcol = imagecolorat($image, $x, $y); $newcol = imagecolorat($image, $x + $distx, $y +$disty); imagesetpixel($image, $x, $y, $newcol); imagesetpixel($image, $x + $distx, $y + $disty,$oldcol); } } } $image = imagecreatefrompng("images/tandemtruecol-new.png"); scatter($image); header("Content-type: image/png"); imagepng($image); imagedestroy($image); ?>
REVERSE COLOR	Right click, select all, ctrl+c to copy. <?php $image = imagecreatefrompng("images/tandemtruecol-new.png"); $image_width = imagesx($image); $image_height = imagesy($image); for ($h = 0; $h < $image_height; $h++) { for ($w = 0; $w < $image_width; $w++) { $colors = imagecolorsforindex($image,imagecolorat($image, $w, $h)); $colors['red'] = 255 - $colors['red']; $colors['green'] = 255 - $colors['green']; $colors['blue'] = 255 - $colors['blue']; $new_color = imagecolorallocate($image, $colors['red'], $colors['green'], $colors['blue']); imagesetpixel($image, $w, $h, $new_color); } } imagepng($image); header("Content-Type: image/png"); imagedestroy($image); ?>
INTERLACE (with lilac)	Right click, select all, ctrl+c to copy. <?php function interlace (&$image) { $imagex = imagesx($image); $imagey = imagesy($image); GLOBAL $lilac; // LOOP THROUGH ALL ROWS IN THE IMAGE for ($y = 0; $y < $imagey; $y+=3) { //IF IT IS EVEN ROW if ($y % 2) { //LOOP THROUGH ALL PIXELS IN THIS ROW for ($x = 0; $x < $imagex; $x+=3) { //SET THEM TO YOUR COLOR (3 places) ImageSetPixel($image, $x, $y, $lilac); } } } } $image = imagecreatefrompng("images/tandemtruecol-new.png"); $lilac = imagecolorallocate($image, 240,55, 240); interlace($image); header("Content-type: image/png"); imagepng($image); imagedestroy($image); ?>
NOISE	Right click, select all, ctrl+c to copy. <?php $im = imagecreatefrompng("images/tandemtruecol-new.png"); header ("Content-type: image/png"); $height=imagesy($im); $width=imagesx($im); $im2=imagecreatetruecolor($width,$height); for ($x=0;$x<$width;$x++){ for ($y=0;$y<$height;$y++){ $rgb = ImageColorAt($im, $x, $y); $r = ($rgb >> 16) & 0xFF; $g = ($rgb >> 8) & 0xFF; $b = $rgb & 0xFF; $r2=$r; $g2=$g; $b2=$b; $r=$r2+$g2+$b2; $g=$r2+$g2+$b2; $b=$r2+$g2+$b2; $c[1] = imagecolorallocate($im2, $r, $g, $b); $c[2] = imagecolorallocate($im2, $r2, $g, $b2); $c[3] = imagecolorallocate($im2, $r2, $g2, $b); $c[4] = imagecolorallocate($im2, $r/2, $g/2, $b/2); $c[5] = imagecolorallocate($im2, $r2/2, $g/2, $b2/2); $number = rand(1,5); $colour = $c[$number]; imagesetpixel($im2, $x, $y, $colour); } } imagepng($im2); imagedestroy($im); imagedestroy($im2); ?>
SWIRL	Right click, select all, ctrl+c to copy. <?php //code by DJMike $image = imagecreatefrompng("images/tandemtruecol-new.png"); function displacement($i, $deg ) { $width = imagesx($i); $height = imagesy($i); $fDegree = deg2rad($deg)/180; #$fDegree = rad2deg($deg); #$fDegree = $deg; for ($y=0;$y<$height;$y++) { for ($x=0;$x<$width;$x++) { $pos_x = $x - ($width/2); $pos_y = $y - ($height/2); $theta = atan2(($pos_y),($pos_x)); $radius = sqrt($pos_x$pos_x + $pos_y$pos_y); $newX = ($width/2) + ($radius * cos($theta + ($fDegree * $radius))); if ($newX > 0 && $newX < $width) { $dis_x = $newX; } else { $dis_x = $x; } $newY = ($height/2) + ($radius * sin($theta + ($fDegree * $radius))); if ($newY > 0 && $newY < $height) { $dis_y = $newY; } else { $dis_y = $y; } $dis_x = ($dis_x < 0) ? $dis_x + $width : $dis_x; $dis_x = ($dis_x >= $width) ? $dis_x - $width : $dis_x; $dis_y = ($dis_y < 0) ? $dis_y + $height : $dis_y; $dis_y = ($dis_y >= $height) ? $dis_y - $height : $dis_y; $displacement['x'][$x][$y] = $dis_x; $displacement['y'][$x][$y] = $dis_y; } } return $displacement; } function imagedisplace($i,$displacement) { $width = imagesx($i); $height = imagesy($i); $temp = imagecreatetruecolor($width,$height); imagecopy($temp,$i,0,0,0,0,$width,$height); for ($y=0;$y<$height;$y++) { for ($x=0;$x<$width;$x++) { $rgb = imagecolorat($temp,$displacement['x'][$x][$y], $displacement['y'][$x][$y]); $a = ($rgb >> 24) & 0xFF; $r = ($rgb >> 16) & 0xFF; $g = ($rgb >> 8) & 0xFF; $b = $rgb & 0xFF; $col = imagecolorallocatealpha($i,$r,$g,$b,$a); imagesetpixel($i,$x,$y,$col); } } imagedestroy($temp); return $i; } //ENTER SWIRL AMOUNT $displacement = displacement($image, 5000); $image = imagedisplace($image,$displacement); header("content-type: image/png"); imagepng($image); imagedestroy($image); ?>
WAVE	Right click, select all, ctrl+c to copy. <?php //code by DJMike function wave($url, $amp, $step) { /* $url = source image $amp = amplitude $step = multiplies wavelength / list($w, $h, $type, $attr) = getimagesize("$url"); $image = imagecreatefrompng("$url"); $wave = imagecreatetruecolor($w, $h); $black=imagecolorallocate($wave,0,0,0); imagecolortransparent($wave,$black); # copy from left to right for ($x = 0; $x <= $w; $x++) { $offset = $x$step; $offset = deg2rad($offset); $offset = $amp*sin($offset)+$amp; imagecopyresampled($wave, $image, $x, $offset/2, $x, 0, 1, $h-$offset, 1, $h); # $step = $step+$step; } return $wave; } ########################## $url = "images/tandemtruecol-new.png"; $wave = wave("$url", 10,9); header("content-type: image/png"); imagepng($wave,'images/effectwave.png'); imagedestroy($wave); ?>
COLORIZE	Right click, select all, ctrl+c to copy. <?php function imagefilterhue($im,$r,$g,$b){ $rgb = $r+$g+$b; $col = array($r/$rgb,$b/$rgb,$g/$rgb); $height = imagesy($im); $width = imagesx($im); for($x=0; $x<$width; $x++){ for($y=0; $y<$height; $y++){ $rgb = ImageColorAt($im, $x, $y); $r = ($rgb >> 16) & 0xFF; $g = ($rgb >> 8) & 0xFF; $b = $rgb & 0xFF; $newR = $r$col[0] + $g$col[1] + $b$col[2]; $newG = $r$col[2] + $g$col[0] + $b$col[1]; $newB = $r$col[1] + $g$col[2] + $b*$col[0]; imagesetpixel($im, $x, $y,imagecolorallocate($im, $newR, $newG, $newB)); } } } header ("Content-type: image/png"); $im = imagecreatefrompng("images/tandemtruecol-new.png"); // Usage: Just as imagefilter(), except with no filtertype. // imagefilterhue(resource $image, int $red, int $green , int $blue) imagefilterhue($im,-25,25,-25); imagepng($im,'images/effectcolorize.png'); imagedestroy($im) ?>
EDGE DETECT	Right click, select all, ctrl+c to copy. <?php function edge($input, $output) { $in_im = imageCreateFrompng($input); $gx = array(array(-1, 0, 1), array(-2, 0, 2), array(-1, 0, 1)); $gy = array(array(-1, -2, -1), array(0, 0, 0), array(1, 2, 1)); $x = imagesx($in_im); $y = imagesy($in_im); $out_im = imagecreatetruecolor($x, $y); $colors = array(255 => imagecolorallocate($out_im, 255, 255, 255)); for ($row = 1; $row < $x; $row++) { for ($col = 1; $col < $y; $col++) { $eyedropper =imagecolorat($in_im, $x, $y); $color =imagecolorsforindex($in_im, $eyedropper); $pxval = ($color['red'] + $color['green'] + $color['blue']) / 3; $pixel_gx = $pixel_gy = 0; for ($i = -1; $i < 2; $i++) { for ($j = -1; $j < 2; $j++) { $eyedropper =imagecolorat($in_im, $row+$i, $col+$j); $color =imagecolorsforindex($in_im, $eyedropper); $val = ($color['red'] + $color['green'] + $color['blue']) / 3; $pixel_gx += $gx[$i+1][$j+1] * $val; $pixel_gy += $gy[$i+1][$j+1] * $val; } } $pixel = sqrt($pixel_gx * $pixel_gx + $pixel_gy * $pixel_gy); $pixel = abs(255 - (int)$pixel); if (!isset($colors[$pixel])) $colors[$pixel] = imagecolorallocate($out_im, $pixel, $pixel, $pixel); imageSetPixel($out_im, $row, $col, $colors[$pixel]); } } imagejpeg($out_im, $output, 75); } header("Content-type: image/jpeg"); //DOES NOT OUTPUT PNG (TRANSPARENCY) edge('images/tandemtruecol-new.png', 'effectedgeD.jpg'); imagedestroy($out_im); ?>
GRAYSCALE	Right click, select all, ctrl+c to copy. <?php $image = imagecreatefrompng("images/tandemtruecol-new.png"); $image_width = imagesx($image); $image_height = imagesy($image); for ($h = 0; $h < $image_height; $h++) { for ($w = 0; $w < $image_width; $w++) { $colors = imagecolorsforindex($image, imagecolorat($image, $w, $h)); $grayed_color = ($colors['red'] + $colors['green'] + $colors['blue']) / 3; $new_color = imagecolorallocate($image, $grayed_color, $grayed_color, $grayed_color); imagesetpixel($image, $w, $h, $new_color); } } imagepng($image); header("Content-Type: image/png"); imagedestroy($image); ?>

Image Effects with PHP and GD