Am 3/21/2018 um 12:30 schrieb Stephen:
> On 21/03/2018 10:52, Ive wrote:
>>
>> And a general note to everybody who's posting images to theses 
>> newsgroups: please make sure your JPEG image contains a ICC profile.
> 
> How do I do that? 

See my reply to Thomas.

> Does it apply to PovRay generated png's?
> 
PNG's are a very sad story and the ones generated by POV-Ray are no 
exception. For short: there is absolutely no way you can predict what 
anybody else will see when you post a PNG on the web. And there is no 
way to work around this.

-Ive

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Am 21.03.2018 um 11:52 schrieb Ive:

> And a general note to everybody who's posting images to theses
> newsgroups: please make sure your JPEG image contains a ICC profile.
> Since about 2 months Firefox and Thunderbird have full color management
> enabled by default. Chrome and Opera do the same since quite a while,
[...]
> As color
> management only kicks in for images with ICC profiles I have to save the
> image to my local disk and check *if* it contains a profile and if not
> use my own image viewer that correctly assumes for images without
> profile to be in sRGB and transforms them correctly to my viewing device
> profile.

I'd call that a bullshitty implementation then. After all, the W3C
officially recommends sRGB for all web content, so that's what browsers
should default to if an ICC profile is not embedded.

Also, a lot of images posted here are rendered with POV-Ray, which
currently does not embed an ICC profile. So to comply with your request,
each and every image would have to be post-processed before posting,
which I consider unreasonable.

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Am 21.03.2018 um 14:14 schrieb Ive:

> PNG's are a very sad story and the ones generated by POV-Ray are no
> exception. For short: there is absolutely no way you can predict what
> anybody else will see when you post a PNG on the web. And there is no
> way to work around this.

... which, I'd like to emphasize, is not POV-Ray's fault: If output is
set to `File_Gamma=sRGB` (the default), POV-Ray embeds an sRGB chunk,
which according to the PNG standard should communicate plain as hell
that the colour space is supposed to be sRGB.

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Am 21.03.2018 um 13:11 schrieb Thomas de Groot:

> I agree for the vegetation, maybe the wheel, not really for the bricks.
> However, my question would be: where does over-saturation come from?
> 
> It is strange. The original is - imo - strongly under-saturated.

Those are Poser figures, so I presume their materials also use Poser
texture images.

MegaPOV 1.2.1 - being based on POV-Ray v3.6 - completely ignored gamma
for input images; if you already used `assumed_gamma 1.0` back then - as
every good sailor should - MegaPOV 1.2.1 / POV-Ray v3.6 would
erroneously presume the input images to match that gamma.

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On 21-3-2018 14:07, Ive wrote:
> Am 3/21/2018 um 13:11 schrieb Thomas de Groot:
>> I agree for the vegetation, maybe the wheel, not really for the 
>> bricks. However, my question would be: where does over-saturation come 
>> from?
>>
> Gamma! In the ancient time of MegaPOV and its unawareness of gamma 
> handling you as the user had to tweak scene colors and lighting to 
> compensate for the resulting inconsistency. Now with proper gamma 
> handling but some of these *tweaks* making it over results in 
> over-saturation and slightly hue shifts - as to be expected.
> 
>> It is strange. The original is - imo - strongly under-saturated.
>>
> Yes, I agree - saturation is certainly also a matter of taste - 
> personally I can live with under-saturation better than with 
> over-saturation.

Then the short answer is clear: My latest scene version using 
exclusively sRGB gamma all through (and gamma 1.0 where necessary) the 
apparent over-saturation is solely due to the original hue of the used 
image_maps. I can live with that although I prefer a slightly 
less-saturated version; it might me make to consider to tweak the 
original images to a "lighter", "flatter" hue, or to apply a colour 
transformation within POV-Ray.

> 
>>
>> Hmmm... I don't know how to achieve that...
>>
> 
> Contemporary versions of Photoshop and Lightroom do this auto-magical, 
> older version if you told them to do so and I'm under the assumption 
> this is also true for other software like Gimp or Paintshop. I do not 
> use the latter so maybe I'm wrong?
> 

I am using Gimp and have not (yet) found thematter. Does your IC do it 
by the way?

-- 
Thomas

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On 22-3-2018 3:34, clipka wrote:
> Am 21.03.2018 um 13:11 schrieb Thomas de Groot:
> 
>> I agree for the vegetation, maybe the wheel, not really for the bricks.
>> However, my question would be: where does over-saturation come from?
>>
>> It is strange. The original is - imo - strongly under-saturated.
> 
> Those are Poser figures, so I presume their materials also use Poser
> texture images.

Yes indeed. They render much better with the latest version of POV-Ray 
or UberPOV.

> 
> MegaPOV 1.2.1 - being based on POV-Ray v3.6 - completely ignored gamma
> for input images; if you already used `assumed_gamma 1.0` back then - as
> every good sailor should - MegaPOV 1.2.1 / POV-Ray v3.6 would
> erroneously presume the input images to match that gamma.
> 

I did and it did. :_)

-- 
Thomas

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Am 3/22/2018 um 3:22 schrieb clipka:
> I'd call that a bullshitty implementation then. After all, the W3C
> officially recommends sRGB for all web content, so that's what browsers
> should default to if an ICC profile is not embedded.
> 
> Also, a lot of images posted here are rendered with POV-Ray, which
> currently does not embed an ICC profile. So to comply with your request,
> each and every image would have to be post-processed before posting,
> which I consider unreasonable.
> 

You don't get my point. In practice nowadays nobody cares what the W3C 
did recommend a long time ago when monitors where CRT's and smartphones 
where not invented yet.
The color space of the majority of viewing devices currently used is not 
even close to sRGB and with upcoming 4k displays and even HDR displays 
for the consumer market they get even farer away. And as I mentioned 
before, this does not make just a subtle difference.
This was also not a personal request of mine (I know about the problems 
very well and can work around it if I want to), it is an advice for 
everybody who cares about what others will see if they look at an image 
one might have created with a lot of effort.
So what you call a bullshitty implementation is what I call a necessary 
step in the right direction.

-Ive

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Am 3/22/2018 um 8:47 schrieb Thomas de Groot:
> 
> Does your IC do it 
> by the way?
> 

Ouch! You just ruined my day and almost my marriage as I promised my 
wife to do some cleanup in the garden this morning.

Anyway, I just realized that the IC version on my webpage is 8 years old 
(doesn't time fly by?) and therefor completely outdated. I just did put 
up a more resent 64-bit version of IC that supports ICC profiles for 
writing TIFF and JPEG files.

And BTW when I tried to maintain my website I noticed that FireFTP (the 
Firefox plugin I was using for this purpose since a decade) does not 
work anymore as Mozilla has changed its plugin policy and so had to 
spend hours to find some replacement that at least works somehow in the 
way I like it.
This also reminded me that I wanted to change my side from http to https 
... oh my, so many things to do and so less time ...

-Ive

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On 22-3-2018 12:47, Ive wrote:
> Am 3/22/2018 um 8:47 schrieb Thomas de Groot:
>>
>> Does your IC do it by the way?
>>
> 
> Ouch! You just ruined my day and almost my marriage as I promised my 
> wife to do some cleanup in the garden this morning.

Oh, the garden can wait. IC is much more important than either marriage 
or gardens, isn't it! ;-)

> 
> Anyway, I just realized that the IC version on my webpage is 8 years old 
> (doesn't time fly by?) and therefor completely outdated. I just did put 
> up a more resent 64-bit version of IC that supports ICC profiles for 
> writing TIFF and JPEG files.
> 
> And BTW when I tried to maintain my website I noticed that FireFTP (the 
> Firefox plugin I was using for this purpose since a decade) does not 
> work anymore as Mozilla has changed its plugin policy and so had to 
> spend hours to find some replacement that at least works somehow in the 
> way I like it.
> This also reminded me that I wanted to change my side from http to https 
> ... oh my, so many things to do and so less time ...
> 

Well, I shall expect a new version by tomorrow then... ;-)

-- 
Thomas

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Am 3/22/2018 um 13:07 schrieb Thomas de Groot:
> Oh, the garden can wait. IC is much more important than either marriage 
> or gardens, isn't it! ;-)
> 
Yeah, sure!

> 
> Well, I shall expect a new version by tomorrow then... ;-)
> 
You misunderstood. The maintained site is already up and running and IC 
1.1.7 64-bit ready to download.


-Ive

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