Search found 109 matches
- 2010-04-21T10:54:30-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
contrast-stretch with no -channel selection should not change color balance, neither should linear-stretch. at least it does not in non_hdri to my knowledge. That is what I said, with a caveat... if channels are changes in sync the color won't change but, OTOH if you do that you'll burn much more p...
- 2010-04-21T03:30:06-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
In that specific operation I'm trying to stretch contrast while not burning more than X% pixels and blacking out more than Y% pixels. My definition of "burn" and "black out" is, it seems, different from the current one used in ImageMagick: I would consider that if one channel bur...
- 2010-04-20T20:03:53-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
The thing is, in the docs it says:
"All the channels are normalized in concert by the came amount so as to preserve color integrity, when the default +channel setting is in use."
I can't see where color integrity is being preserved here at 0.0001% levels or whatever is specified...
"All the channels are normalized in concert by the came amount so as to preserve color integrity, when the default +channel setting is in use."
I can't see where color integrity is being preserved here at 0.0001% levels or whatever is specified...
- 2010-04-20T19:59:29-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
Linear stretches from full black and white, so that is why it does nothing for -linear-stretch 0. If your min and max graylevels are far from black and white, any small clip amount will jump all the way to those graylevels for linear-stretch and will go a little further for -contrast-stretch as it ...
- 2010-04-20T19:31:44-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
When I read the current ImageMagick documentation what I see is that linear-stretch does the same as contrast-stretch, but instead of using the histogram as a lookup table it calculates the correct factors for use in "level" and then issues it internally. All 3 operators are now -channel/+...
- 2010-04-20T15:01:03-07:00
- Forum: Users
- Topic: Histogram with huge file size...
- Replies: 7
- Views: 16922
Re: Histogram with huge file size...
Thanks guys, once again!
- 2010-04-20T14:53:44-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Re: Strange behavior in linear_stretch with HDRI (6.6.1-4)
While it is true linear-stretch 0%x0% does not change the image there is an auto-level just before it, doing what linear-stretch 0%-0% should do in the first place (IMHO), so it's a wash: it does nothing but the work was already done anyway. In an image as small as this one burning 0.0001% is nothin...
- 2010-04-20T13:17:55-07:00
- Forum: Bugs
- Topic: Strange behavior in linear_stretch with HDRI (6.6.1-4)
- Replies: 21
- Views: 40213
Strange behavior in linear_stretch with HDRI (6.6.1-4)
[reviewed below] This is a strange behavior in linear stretch... convert input.exr -auto-level -linear-stretch 0%x0% -gamma 2 -channel Red -gamma 1 -channel Green -gamma 0.9 -channel Blue -gamma 1.02 +channel -depth 16 -sigmoidal-contrast 5x27.5% -set option:modulate:colorspace hsb -modulate 100,500...
- 2010-04-19T16:10:24-07:00
- Forum: Bugs
- Topic: Bug in gamma+linear_stretch with HDRI (6.6.1-3)
- Replies: 2
- Views: 5868
Re: Bug in gamma+linear_stretch with HDRI (6.6.1-3)
I confirm the bug is solved. Apart from this small bugs I've found ImageMagick is doing an excellent work in HDRI post processing, mixing results from a bunch of tonemappings, etc... Together with pfstools makes one of the most powerful toolchains for HDRI processing. As always: thanks for this grea...
- 2010-04-16T04:34:51-07:00
- Forum: Bugs
- Topic: Bug in gamma+linear_stretch with HDRI (6.6.1-3)
- Replies: 2
- Views: 5868
Bug in gamma+linear_stretch with HDRI (6.6.1-3)
I'm not so sure if this is an actual bug, since one of the operations generates values out of range... nevertheless I'm reporting it for you to appreciate. convert input.exr -gamma 2.0 -linear-stretch 0.01%x0.01% -depth 8 -interlace line -quality 98 -sampling-factor 1x1 output.jpg If you either remo...
- 2010-04-16T04:28:35-07:00
- Forum: Bugs
- Topic: Bug in modulate with HDRI (6.6.0-9)
- Replies: 9
- Views: 18910
Re: Bug in modulate with HDRI (6.6.0-9)
Ok, the bug in modulate seems solved, now I have another one... in another thread
- 2010-04-15T18:54:59-07:00
- Forum: Users
- Topic: Histogram with huge file size...
- Replies: 7
- Views: 16922
Re: Histogram with huge file size...
Nice, now is there someway to make it run faster without -filter Point -resize 50% or similar extreme measures?
- 2010-04-15T17:53:36-07:00
- Forum: Users
- Topic: Histogram with huge file size...
- Replies: 7
- Views: 16922
Re: Histogram with huge file size...
Found the answer myself: the image contains, in comments, the entire list of colors with the color count for each one! The correct way to sort this out in a single "convert" is something like this: convert input.jpg -write histogram:mpr:xpto +delete mpr:xpto -strip -evaluate Divide 2 -eval...
- 2010-04-15T16:55:15-07:00
- Forum: Users
- Topic: Histogram with huge file size...
- Replies: 7
- Views: 16922
Histogram with huge file size...
Hi! When I generate a histogram for an image with a command like: convert xpto.jpg histogram:output.png The output.png file tends to be huge, something like 300k or more... Now, if I do this: convert xpto.jpg histogram:- | convert - output.png The same exact histogram is generated (of course!) but n...
- 2010-04-12T18:58:04-07:00
- Forum: Bugs
- Topic: Bug in modulate with HDRI (6.6.0-9)
- Replies: 9
- Views: 18910
Re: Bug in modulate with HDRI (6.6.0-9)
Hum... interesting it's only in HSL, because as I wrote previously the error occurred with all 3 colorspaces supported by modulate, unless I was doing something wrong :roll: I'll check it tomorrow, as soon as I get my hands on that new version ;) Thanks again for the fast answer! I'm using ImageMagi...