PHP中实现图片的锐化
<? //读取图像的类型 //1 = gif, 2 = jpg, 3 = png, 4 = swf, 5 = psd, 6 = bmp, 7 = tiff(intel byte order), 8 = tiff(motorola byte order), 9 = jpc, 10 = jp2, 11 = jpx, 12 = jb2, 13 = swc, 14 = iff function getimagetype($filename) {return (($imginfo=@getimagesize($filename))!=null ? $imginfo[2] : null);} //图像锐化 //$scr_im:图像资源句柄,$degree:锐化度数 function sharp(&$src_im, &$dst_im, $degree) { $src_x = imagesx($src_im); $src_y = imagesy($src_im); //$dst_im = imagecreate($src_x, $src_y); //imagecopy($dst_im, $src_im, 0, 0, 0, 0, $src_x, $src_y); $cnt = 0; for ($x=1; $x<$src_x; $x++) for ($y=1; $y<$src_y; $y++) { $src_clr1 = imagecolorsforindex($src_im, imagecolorat($src_im, $x-1, $y-1)); $src_clr2 = imagecolorsforindex($src_im, imagecolorat($src_im, $x, $y)); $r = intval($src_clr2["red"]+$degree*($src_clr2["red"]-$src_clr1["red"])); $g = intval($src_clr2["green"]+$degree*($src_clr2["green"]-$src_clr1["green"])); $b = intval($src_clr2["blue"]+$degree*($src_clr2["blue"]-$src_clr1["blue"])); $r = min(255, max($r, 0)); $g = min(255, max($g, 0)); $b = min(255, max($b, 0)); //echo "r:$r, g:$g, b:$b<br/>"; if (($dst_clr=imagecolorexact($dst_im, $r, $g, $b))==-1) $dst_clr = imagecolorallocate($dst_im, $r, $g, $b); $cnt++; if ($dst_clr==-1) die("color allocate faile at $x, $y ($cnt)."); imagesetpixel($dst_im, $x, $y, $dst_clr); } return $dst_im; } $imagefunctions = array("imagecreatefromwbmp", "imagecreatefromgif", "imagecreatefromjpeg", "imagecreatefrompng"); if (!empty($_post["imagename"])) { set_time_limit(10*60); if (($imagetype=getimagetype($_post["imagename"]))==false) die("指定文件不存在或不是有效的图片或不支持类型!"); if ($imagetype==6) $imagetype = 0; if ($imagetype>3) die("不支持的图片类型!"); $im1 = $imagefunctions[$imagetype]($_post["imagename"]); $im2 = $imagefunctions[$imagetype]($_post["imagename"]); //print_r(imagecolorsforindex($im, imagecolorat($im, 10, 10))); sharp($im1, $im2, $_post["degree"]); header("content-type: image/png"); imagepng($im2); imagedestroy($im1); imagedestroy($im2); } ?>
Tag:
锐化