Page 1 of 1
How to add unsharp mask to this code?
Posted: 2016-12-16T10:30:20-07:00
by Amin Sabet
I am using a forum software called Xenforo, which resizes images using Imagick.
If the code says:
Code: Select all
foreach ($this->_image AS $frame)
{
$frame->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 0.9, true); // keep EXIF
$frame->setImagePage($frame->getImageWidth(), $frame->getImageHeight(), 0, 0);
}
and later in the code this:
Code: Select all
if ($scaleUp)
{
$frame->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 0.9, true);
}
else if ($oldImagick)
{
$frame->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 0.9, true); // keep EXIF
}
else
{
$frame->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 0.9, true); // higher-quality scaling + EXIF retained
}
$frame->setImagePage($width, $height, 0, 0);
}
How can I add a little unsharp mask to those resize operations?
Re: How to add unsharp mask to this code?
Posted: 2016-12-16T10:58:39-07:00
by Bonzo
It is interesting that all four resize options do exactly the same thing.
I do not use Imagick but would try adding this line below the $frame->resizeImage( option you are using:
$frame->unsharpMaskImage(0 , 0.5 , 1 , 0.05);
Re: How to add unsharp mask to this code?
Posted: 2016-12-16T13:12:02-07:00
by Amin Sabet
In the default Xenforo code, the resize options does different things:
Code: Select all
foreach ($this->_image AS $frame)
{
if ($scaleUp)
{
$frame->resizeImage($width, $height, Imagick::FILTER_QUADRATIC, .5, true);
}
else if ($oldImagick)
{
$frame->thumbnailImage($width, $height, true);
}
else
{
$frame->thumbnailImage($width, $height, true, true);
}
$frame->setImagePage($width, $height, 0, 0);
}
I changed them to do the same thing because I didn't want them to strip out EXIF. I suppose I could have taken out the if / else stuff and just written it once
.
Thanks for your help, I will try what you wrote.
Re: How to add unsharp mask to this code?
Posted: 2016-12-16T13:24:25-07:00
by Amin Sabet
So this is what I put:
Code: Select all
foreach ($this->_image AS $frame)
{
$frame->resizeImage($width, $height, Imagick::FILTER_LANCZOS, 0.9, true);
$frame->unsharpMaskImage(0 , 0.5 , 1 , 0.05);
$frame->setImagePage($frame->getImageWidth(), $frame->getImageHeight(), 0, 0);
But as far as I can tell there is no difference in sharpening being applied.
Re: How to add unsharp mask to this code?
Posted: 2016-12-16T13:34:09-07:00
by snibgo
0.5 is a small amount of unsharpening. A larger number like 5 is more obvious.