Translate IM's unsharpMaskImage() to VIPS's vips_sharpen()

[davidb2002]

I'm currently using ImageMagick to resize and sharpen images. I'm now moving to VIPS due to performance reasons and the need for a quick, on the fly resizer.

I use imageMagick's unsharpMask (http://php.net/manual/en/imagick.unsharpmaskimage.php) feature to sharpen a photo after resizing it. I'm currently using the following settings:

Radius: 0
Sigma: .5
Amount: .25
threshold: .008

vips_sharpen (http://www.vips.ecs.soton.ac.uk/support ... ps-sharpen) has a number of additional parameters which i'm trying to replicate the same sharpening results.

Does anyone know an easy way to work out the VIPS traslation of the imagemagick unsharp mask settings?