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by NicolasRobidoux
2014-07-09T06:02:17-07:00
Forum: Announce
Topic: Windows/Linux/OSX ImageMagick GUI
Replies: 9
Views: 53622

Re: Windows/Linux/OSX ImageMagick GUI

Off the top of my head: Load/save format is a separate thing from what it uses to compute internally: http://www.imagemagick.org/Usage/basics/#hdri_formats . It most likely will affect speed. I don't think x2, however, if you bundle with IM7. A small factor, esp. if you compile IM with optimizing fl...
by NicolasRobidoux
2014-07-08T10:53:40-07:00
Forum: Announce
Topic: Windows/Linux/OSX ImageMagick GUI
Replies: 9
Views: 53622

Re: Windows/Linux/OSX ImageMagick GUI

John:
Would you consider making the IM version that's bundled with NIP2 be the floating point (HDRI) one by default?
This, I think, would be quite attractive to many users.
by NicolasRobidoux
2014-07-05T02:21:11-07:00
Forum: Users
Topic: The quality of re-sized image is not good
Replies: 36
Views: 40283

Re: The quality of re-sized image is not good

Current abbreviated "general purpose" short list: http://www.dpreview.com/forums/post/53970721
by NicolasRobidoux
2014-07-03T12:40:52-07:00
Forum: Announce
Topic: Windows/Linux/OSX ImageMagick GUI
Replies: 9
Views: 53622

Re: Windows/Linux/OSX ImageMagick GUI

What can I say besides "\o/"?
by NicolasRobidoux
2014-07-03T08:00:41-07:00
Forum: Announce
Topic: Windows/Linux/OSX ImageMagick GUI
Replies: 9
Views: 53622

Windows/Linux/OSX ImageMagick GUI

News from John Cupitt, lead dev of NIP2 (New Image Processor 2) http://www.vips.ecs.soton.ac.uk/index.php?title=Nip2 the GUI of the graphics library libvips, but also now for several ImageMagick operations: Hi Nicolas, I've just put up nip2 7.40.2: http://www.vips.ecs.soton.ac.uk/supported/7.40/win3...
by NicolasRobidoux
2014-06-30T07:28:23-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

I'm starting to think that the best way to improve sigmoidization is to replace by a blend of an enlargement through a gamma space and an enlargement through linear light.
In other words, the best way to improve sigmoidization >>for natural images<< is to use something else.
by NicolasRobidoux
2014-06-29T12:17:23-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

Another result (EWA Lanczos through gamma 2.5) here: http://www.dpreview.com/forums/post/53939045
by NicolasRobidoux
2014-06-29T08:49:25-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

Second sample here, with EWA Lanczos and gamma 4: http://www.imagemagick.org/discourse-server/viewtopic.php?f=22&t=21804&p=89728#p89728 ImageMagick (IM 7 running in HDRI (floating point) mode) command: magick input_small.png -set colorspace sRGB -colorspace RGB -gamma 4 -filter lanczos -distort Resi...
by NicolasRobidoux
2014-06-29T00:44:27-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

fmw42 wrote:...
If you can give me an image and a command line (and any variations), I can script a loop to vary whatever parameters you want...
Thank you Fred.
I will think.
Cheers
by NicolasRobidoux
2014-06-28T12:41:43-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

I think that using gamma > 1.8 to suppress the dark halos (hopefully without messing up midtones), linear to suppress the light halos (and preserve colors), and then blending the two putting more of the high gamma, may be a good way to get a good upsampling result. But maybe skipping the linear part...
by NicolasRobidoux
2014-06-28T12:36:24-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

... I just worry that two steps (gamma or sigmoidal) might add more blur (softness) that one can avoid with just one sigmoidal-contrast. If you blend two sharp versions of the same image (and of course they are perfectly aligned), the result should still be sharp. With less artificial acutance (bec...
by NicolasRobidoux
2014-06-28T10:31:46-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

I do not recall that it was my suggestion. Most likely not. Perhaps henrywho? Assuming I did not come up with this idea myself (at least within this circle), I'll ask him if this turns out to work well and he does not "show up". P.S. I don't think it was henriwho. Unless someone sets me straight, I...
by NicolasRobidoux
2014-06-28T10:26:22-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

Have you considered using a more symmetric "soft knee" curve rather than just gamma. see http://www.fmwconcepts.com/imagemagick/kneemap/index.php. Does it make sense to do both gamma>1 and gamma<1 in the same command, each with its own resize rather than processing the image twice and blending? Doe...
by NicolasRobidoux
2014-06-28T10:07:51-07:00
Forum: Users
Topic: Improving sigmoidal image resampling (enlargement)
Replies: 19
Views: 20482

Re: Improving sigmoidal image resampling (enlargement)

Not sure, but I think that just converting to a gamma space in order to work in a "smooth" perceptual space so as to minimize "dark halos", which with photographic material are more bothersome than the "light halos" may give better results with less tweaking than sigmoidizing. Something like magick ...