PHP GD sharpness filter

问题

How can you make a sharpness filter with the PHP GD library?

So that this...

Turns to this...

If it is not possible with PHP, than what other languages are capable?

回答1:

I think he wants to use PHP's GD library. It's pretty easy: function.imageconvolution. Just search for 'sharpen' on the page and you'll see a matrix you can use for sharpening. It works pretty well, although I would recommend using ImageMagick if you're trying to do anything more than that.

回答2:

If the ImageMagick is installed in your PHP config, you can use Imagick::adaptiveSharpenImage

From the manual:

<?php
try {
    $image = new Imagick('image.png');
    $image->adaptiveSharpenImage(2,1);
} catch(ImagickException $e) {
    echo 'Error: ' , $e->getMessage();
    die();
}
header('Content-type: image/png');
echo $image;
?>

http://php.net/manual/en/function.imagick-adaptivesharpenimage.php

回答3:

There is a library called Unsharp Mask PHP, which does exactly what you need. http://vikjavev.no/computing/ump.php

来源：https://stackoverflow.com/questions/3576550/php-gd-sharpness-filter