+++ /dev/null
-<?php
-//////////////////////////////////////////////////////////////
-//// ////
-//// 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. ////
-//// ////
-//////////////////////////////////////////////////////////////
-/// From: http://vikjavev.no/hovudsida/umtestside.php //
-// //
-// Reformatted by James Heinrich <info@silisoftware.com> //
-// for use in phpThumb() on 3 February 2003. //
-// //
-// phpThumb() is found at http://phpthumb.sourceforge.net ///
-//////////////////////////////////////////////////////////////
-
-/*
-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.
-*/
-
-class phpUnsharpMask {
-
- function applyUnsharpMask(&$img, $amount, $radius, $threshold) {
-
- // $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:
- $amount = min($amount, 500);
- $amount = $amount * 0.016;
- if ($amount == 0) {
- return true;
- }
-
- $radius = min($radius, 50);
- $radius = $radius * 2;
-
- $threshold = min($threshold, 255);
-
- $radius = abs(round($radius)); // Only integers make sense.
- if ($radius == 0) {
- return true;
- }
-
- $w = ImageSX($img);
- $h = ImageSY($img);
- $imgCanvas = ImageCreateTrueColor($w, $h);
- $imgCanvas2 = ImageCreateTrueColor($w, $h);
- ImageCopy($imgCanvas, $img, 0, 0, 0, 0, $w, $h);
- ImageCopy($imgCanvas2, $img, 0, 0, 0, 0, $w, $h);
-
-
- $builtinFilterSucceeded = false;
- if ($radius == 1) {
- if (phpthumb_functions::version_compare_replacement(phpversion(), '5.0.0', '>=') && phpthumb_functions::gd_is_bundled()) {
- if (ImageFilter($imgCanvas, IMG_FILTER_GAUSSIAN_BLUR) && ImageFilter($imgCanvas2, IMG_FILTER_GAUSSIAN_BLUR)) {
- $builtinFilterSucceeded = true;
- }
- }
- }
-
- if (!$builtinFilterSucceeded) {
- $imgBlur = ImageCreateTrueColor($w, $h);
- $imgBlur2 = ImageCreateTrueColor($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, $h);
- }
- ImageDestroy($imgBlur);
- ImageDestroy($imgBlur2);
- }
-
- // Calculate the difference between the blurred pixels and the original
- // and set the pixels
- for ($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);
-
- return true;
- }
-
-}
-
-?>
\ No newline at end of file
projects / atutor.git / blobdiff