phpthumb.unsharp.php

是一款免费的轻量级论坛软件

<?php
class phrevosharpMask
{
	function applyUnsharpMask(&$img, $amount, $radius, $threshold)
	{
		$amount = min($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));
		if ($radius == 0)
		{
			return true;
		}
		$w = ImageSX($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, $h);
		for ($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,     $h);
			ImageCopy     ($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, $h);
		}
		for ($x = 0; $x < $w; $x++)
		{
			for ($y = 0; $y < $h; $y++)
			{
				$rgbOrig = ImageColorAt($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);
				$rNew = (abs($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 true;
	}
}
?>