Home > Article > Backend Development > Implement image sharpening code using PHP_PHP tutorial
//Type of read image
//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 ? $imginfo[2] : null);}
//Image sharpening
//$scr_im : Image resource handle, $degree: sharpening degree
Function Sharp(&$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"])); ]-$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: $b
";
if (($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("The specified file does not exist or is not a valid image or does not support the type! ");
if ($ImageType==6) $ImageType = 0;
if ($ImageType>3) die("Unsupported image type!");
$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);
}
?>