웹마스터 팁

원본위치

http://www.vikjavev.com/hovudsida/umtestside.php

원본위치에 가서 test해보세요...

제로보드와 아직 연동 test 소스 변경은 못했지만.
고수님들 참고 하시면 될듯..

글구.. 썸네일 생성시 확실히 화질 차이가 납니다..

------------



<?php

/*

WARNING! Due to a known bug in PHP 4.3.2 this script is not working well in this version. The sharpened images get too dark. The bug is fixed in version 4.3.3.


Unsharp masking is a traditional darkroom technique that has proven very suitable for
digital imaging. The principle of unsharp masking is to create a blurred copy of the image
and compare it to the underlying original. The difference in colour values
between the two images is greatest for the pixels near sharp edges. When this
difference is subtracted from the original image, the edges will be
accentuated.

The Amount parameter simply says how much of the effect you want. 100 is 'normal'.
Radius is the radius of the blurring circle of the mask. 'Threshold' is the least
difference in colour values that is allowed between the original and the mask. In practice
this means that low-contrast areas of the picture are left unrendered whereas edges
are treated normally. This is good for pictures of e.g. skin or blue skies.

Any suggenstions for improvement of the algorithm, expecially regarding the speed
and the roundoff errors in the Gaussian blur process, are welcome.

*/

function UnsharpMask($img, $amount, $radius, $threshold)        {

////////////////////////////////////////////////////////////////////////////////////////////////
////
////                  p h p U n s h a r p M a s k
////
////        Unsharp mask algorithm by Torstein Hønsi 2003.
////                 thoensi_at_netcom_dot_no.
////                   Please leave this notice.
////
///////////////////////////////////////////////////////////////////////////////////////////////


        // $img is an image that is already created within php using
        // imgcreatetruecolor. No url! $img must be a truecolor image.

        // Attempt to calibrate the parameters to Photoshop:
        if ($amount > 500)        $amount = 500;
        $amount = $amount * 0.016;
        if ($radius > 50)        $radius = 50;
        $radius = $radius * 2;
        if ($threshold > 255)        $threshold = 255;
        
        $radius = abs(round($radius));         // Only integers make sense.
        if ($radius == 0) {
                return $img; imagedestroy($img); break;                }
        $w = imagesx($img); $h = imagesy($img);
        $imgCanvas = imagecreatetruecolor($w, $h);
        $imgCanvas2 = imagecreatetruecolor($w, $h);
        $imgBlur = imagecreatetruecolor($w, $h);
        $imgBlur2 = imagecreatetruecolor($w, $h);
        imagecopy ($imgCanvas, $img, 0, 0, 0, 0, $w, $h);
        imagecopy ($imgCanvas2, $img, 0, 0, 0, 0, $w, $h);
        

        // Gaussian blur matrix:
        //                                                
        //        1        2        1                
        //        2        4        2                
        //        1        2        1                
        //                                                
        //////////////////////////////////////////////////

        // Move copies of the image around one pixel at the time and merge them with weight
        // according to the matrix. The same matrix is simply repeated for higher radii.
        for ($i = 0; $i < $radius; $i++)        {
                imagecopy ($imgBlur, $imgCanvas, 0, 0, 1, 1, $w - 1, $h - 1); // up left
                imagecopymerge ($imgBlur, $imgCanvas, 1, 1, 0, 0, $w, $h, 50); // down right
                imagecopymerge ($imgBlur, $imgCanvas, 0, 1, 1, 0, $w - 1, $h, 33.33333); // down left
                imagecopymerge ($imgBlur, $imgCanvas, 1, 0, 0, 1, $w, $h - 1, 25); // up right
                imagecopymerge ($imgBlur, $imgCanvas, 0, 0, 1, 0, $w - 1, $h, 33.33333); // left
                imagecopymerge ($imgBlur, $imgCanvas, 1, 0, 0, 0, $w, $h, 25); // right
                imagecopymerge ($imgBlur, $imgCanvas, 0, 0, 0, 1, $w, $h - 1, 20 ); // up
                imagecopymerge ($imgBlur, $imgCanvas, 0, 1, 0, 0, $w, $h, 16.666667); // down
                imagecopymerge ($imgBlur, $imgCanvas, 0, 0, 0, 0, $w, $h, 50); // center
                imagecopy ($imgCanvas, $imgBlur, 0, 0, 0, 0, $w, $h);

                // During the loop above the blurred copy darkens, possibly due to a roundoff
                // error. Therefore the sharp picture has to go through the same loop to
                // produce a similar image for comparison. This is not a good thing, as processing
                // time increases heavily.
                imagecopy ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 50);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 33.33333);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 25);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 33.33333);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 25);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 20 );
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 16.666667);
                imagecopymerge ($imgBlur2, $imgCanvas2, 0, 0, 0, 0, $w, $h, 50);
                imagecopy ($imgCanvas2, $imgBlur2, 0, 0, 0, 0, $w, $h);
                
                }

        // Calculate the difference between the blurred pixels and the original
        // and set the pixels
        for ($x = 0; $x < $w; $x++)        { // each row
                for ($y = 0; $y < $h; $y++)        { // each pixel
                                
                        $rgbOrig = ImageColorAt($imgCanvas2, $x, $y);
                        $rOrig = (($rgbOrig >> 16) & 0xFF);
                        $gOrig = (($rgbOrig >> 8) & 0xFF);
                        $bOrig = ($rgbOrig & 0xFF);
                        
                        $rgbBlur = ImageColorAt($imgCanvas, $x, $y);
                        
                        $rBlur = (($rgbBlur >> 16) & 0xFF);
                        $gBlur = (($rgbBlur >> 8) & 0xFF);
                        $bBlur = ($rgbBlur & 0xFF);
                        
                        // When the masked pixels differ less from the original
                        // than the threshold specifies, they are set to their original value.
                        $rNew = (abs($rOrig - $rBlur) >= $threshold)
                                ? max(0, min(255, ($amount * ($rOrig - $rBlur)) + $rOrig))
                                : $rOrig;
                        $gNew = (abs($gOrig - $gBlur) >= $threshold)
                                ? max(0, min(255, ($amount * ($gOrig - $gBlur)) + $gOrig))
                                : $gOrig;
                        $bNew = (abs($bOrig - $bBlur) >= $threshold)
                                ? max(0, min(255, ($amount * ($bOrig - $bBlur)) + $bOrig))
                                : $bOrig;
                        
                        
                                                
                        if (($rOrig != $rNew) || ($gOrig != $gNew) || ($bOrig != $bNew)) {
                                    $pixCol = ImageColorAllocate($img, $rNew, $gNew, $bNew);
                                    ImageSetPixel($img, $x, $y, $pixCol);
                                }
}
                }

        imagedestroy($imgCanvas);
        imagedestroy($imgCanvas2);
        imagedestroy($imgBlur);
        imagedestroy($imgBlur2);
        
        return $img;

        }
?>

이상입니다.....!!

사용법은 저두 잘은 몰라요.
하지만 고수님들은 잘 알겠죠..


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