Search found 18 matches

by Casper
2016-05-21T13:01:15-07:00
Forum: Digital Image Processing
Topic: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur
Replies: 50
Views: 110224

Re: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur

Sorry. Not sure why it's not showing up for you. This is the URL:
http://i.imgur.com/ZKwoD4L.png

Can you open that one?

I did these steps in PS:
O+(O-GB)-inv(O+inv(GB))

For GB I used radius 3.
by Casper
2016-05-21T12:48:00-07:00
Forum: Digital Image Processing
Topic: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur
Replies: 50
Views: 110224

Re: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur

fmw42 wrote: IM internal unsharp:
im6937hdri convert lena3.png -unsharp 0x3 lena3_im_uns_0x3.png
Interesting..this seems to be the best match to the image I posted above, but it's still not as good as the PS version.
by Casper
2016-05-21T12:42:58-07:00
Forum: Digital Image Processing
Topic: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur
Replies: 50
Views: 110224

Re: The Math Behind Photoshop's Unsharp Mask and Gaussian Blur

Here's the image manually applying the operations in Photoshop, no threshold, using PS Gaussian Blur with radius 3. It's strange that this image is not identical to the one made with ImageMagic. Actually we need a sample from IM _without_ any threshold to be absolutely sure, but it already looks lik...