Search found 75 matches

by Marsu42
2014-07-31T00:33:41-07:00
Forum: Users
Topic: Q8 vs. Q16 speed (& hdri)
Replies: 15
Views: 21091

Re: Q8 vs. Q16 speed (& hdri)

I believe they are mostly talking about memory. Disk space is also affected as you now have 16 bit per channel images rather than 8-bits per channel. Fyi: I found another bit of information on this on http://www.imagemagick.org/script/advanced-unix-installation.php Larger pixel quantums can cause I...
by Marsu42
2014-07-30T13:10:59-07:00
Forum: Users
Topic: Q8 vs. Q16 speed (& hdri)
Replies: 15
Views: 21091

Re: Q8 vs. Q16 speed (& hdri)

I have never done speed trials of Q8 vs Q16 vs Q32, or integer vs HDRI. I'm not aware of anyone else having done this. I would be interested in any results. Right, that would the reason why the description on the IM download page about these versions is so fuzzy: "A Q16 version permits you to read ...
by Marsu42
2014-07-30T12:18:53-07:00
Forum: Users
Topic: Q8 vs. Q16 speed (& hdri)
Replies: 15
Views: 21091

Q8 vs. Q16 speed (& hdri)

Problem: As a simple user, I'm wondering if it's "worth it" to keep two IM versions around - one q8 for speed, one q16 for 48bpp images. I'm on a 2ghz dual-core 4gb ram laptop, so I'm not *that* worried about memory usage like maybe a webserver is. I'm using IM to watermark images and create thumbn...
by Marsu42
2014-07-16T10:09:49-07:00
Forum: Developers
Topic: Req: fix for clipping on negative polaroid geometry
Replies: 0
Views: 2621

Req: fix for clipping on negative polaroid geometry

I hope I hit the correct place for this feature request, if not sorry and feel free to move this thread :-o Problem : I'm currently generating (very nice, btw) multi-line(!) polaroid thumbnails. To make it look less structured and esp. make better use of the space I'm using a minor negative -geometr...
by Marsu42
2014-06-19T03:21:08-07:00
Forum: Users
Topic: Source vs downsampling vs output sharpening?
Replies: 3
Views: 5665

Re: Source vs downsampling vs output sharpening?

Some people say you should do a little sharpening as the first operation, before shifting tones/hues etc. Until recently, I did this. Meaning you don't do it anymore ... why's that? Too much processing power for too little of a result? Or artifacts in certain constellations vs. pure output sharpeni...
by Marsu42
2014-06-19T02:35:29-07:00
Forum: Users
Topic: Source vs downsampling vs output sharpening?
Replies: 3
Views: 5665

Source vs downsampling vs output sharpening?

I have always been puzzled by this and never found a conclusive answer in the general photography forums: When do I apply what amount of sharpening? The possibilities are: 1. before downsizing (esp. Lightroom/PS with ACR since it has access to the original raw bayer pattern and can adapt to the came...
by Marsu42
2014-06-18T03:23:50-07:00
Forum: Users
Topic: Content-aware image extent?
Replies: 4
Views: 4921

Re: Content-aware image extent?

fmw42 wrote:If on unix, see my script imageborder at the link below
Right, thanks, that's it! You can run *nix shell scripts on Windows through cygwin (or msys/mingw) bash just fine btw.
by Marsu42
2014-06-17T12:59:09-07:00
Forum: Users
Topic: Content-aware image extent?
Replies: 4
Views: 4921

Content-aware image extent?

I'd like to add a alpha-masked border around my images, but without cutting too much into the original content. The idea is to inconspicuously extent the outer content of the image to an added border - basically what you would do in Photoshop with extent canvas and context-sensitive fill. Of course ...
by Marsu42
2014-06-14T09:31:52-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

I just saw that im also returns the "standard deviation", so that's probably what I should use for the wm strength. I reckon I need to brush up my statistics knowledge... any hints anyone on how to best measure the "noisiness" of an image to compute the watermark background strength required (blur ...
by Marsu42
2014-06-14T08:27:58-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

- provide traceability for stolen images. I looked into that, but couldn't figure out (yet :-)) how the stegano command of im works - and it doesn't seem to work with convert in the same step anyway, so I can just resort to a dedicated program. I definitely want to add this if I post 100% res image...
by Marsu42
2014-06-14T05:46:35-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

-alpha set -channel A -evaluate set 50%%[/quote] Ugh, fyi: after running this on some real-life pictures this isn't fit for prime time - it has hard breaks on it and reverses color channels though it should really just work on the luma. The good part is that it works on pure black as well as pure w...
by Marsu42
2014-06-13T06:11:45-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

Anything is reversible, in the sense of doing it by hand in Gimp or whatever. Indeed, but you have to know the algorithm and when data loss occurred the reversed image will have less resolution. I just don't want the standard luma watermarked that can be removed by applying the inverse mask. But if...
by Marsu42
2014-06-12T06:39:29-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

2. You can adjust the mask, eg by extending it Thanks, I've got it working - looks great: not "off the shelf", rather unobstrusive but still stands out a bit, plus I imagine it's not reversible that easily w/o major artifacts. 3. Doing a darken or lighten, as required, in a single step is tricky. W...
by Marsu42
2014-06-12T05:08:02-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

Re: How to fx a (pref. non-reversible) watermark background?

The possibilities are endless. Yeah, that would be my problem :-p I'm quite fond of this This is a terrific sample, thanks! As to be expected, I have follow-up questions :-p 1. Bug: In your sample script, the -gravity doesn't do anything over here, the watermark is positioned to the northwest whate...
by Marsu42
2014-06-12T03:39:10-07:00
Forum: Users
Topic: How to fx a (pref. non-reversible) watermark background?
Replies: 12
Views: 10867

How to fx a (pref. non-reversible) watermark background?

I've written a watermarking batch script that puts a semi-transparent plain overlay in the image, brightening or darkening the background according to the image below. It's done by just soft-light'ing a semi-transparent png. The real watermark image/text gets written on top of that. Problem: I would...