POV-Ray : Newsgroups : povray.binaries.images : Monitor Test-Pattern Server Time
23 Apr 2024 20:17:04 EDT (-0400)
  Monitor Test-Pattern (Message 1 to 4 of 4)  
From: Ive
Subject: Monitor Test-Pattern
Date: 25 Oct 2017 04:44:58
Message: <59f04f0a@news.povray.org>
Watch this image in it's original size (1920 x 1080)- otherwise it is 
completely useless.

With a decent monitor you should see (from top to bottom):
12 "black" boxes.
A continuous gray-scale without vertical banding.
12 "white" boxes.
9 "gamma" boxes where the one labeled 2.2 should match the background.

With a not so decent monitor you are probably unable to distinguish the 
4 top-left black boxes and might also see some vertical banding lines 
within the continuous gray-scale. But if you still see 8 top right 
"black" boxes and the 12 white ones you are OK - you just didn't want to 
spend too much money on your viewing device.

In case you see less than 8 "black" boxes or less than 12 "white" boxes 
or get strong banding lines you should at least be aware that your 
monitor is unsuited for judging images and the images you produce with 
POV-Ray will look very different (most likely quite flat) when viewed by 
someone with a decent monitor.


Note that this just tells something about the basic contrast, brightness 
and gamma properties of the monitor - and nothing about it's ability to 
render colors properly.

-Ive


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Attachments:
Download 'cn-testpattern.tif.dat' (99 KB)

From: Kenneth
Subject: Re: Monitor Test-Pattern
Date: 25 Oct 2017 10:15:01
Message: <web.59f09bbd41beb38c89df8d30@news.povray.org>
Ive <ive### [at] lilysoftorg> wrote:
> Watch this image in it's original size (1920 x 1080)- otherwise it is
> completely useless.

Ha! You beat me to it. I've also been working on a test scene (with a color
spectrum added), but haven't quite finished it (I ran into some... uh...gamma
problems...). In my case, it's not an image but a POV-Ray scene(!), to be
rendered. I *hope* to finish it today/tomorrow; I'll post it here.
>
> With a not so decent monitor you are probably unable to distinguish the
> 4 top-left black boxes and might also see some vertical banding lines
> within the continuous gray-scale. But if you still see 8 top right
> "black" boxes and the 12 white ones you are OK - you just didn't want to
> spend too much money on your viewing device.

And all of that is exactly what I see! I'm discovering that my consumer-level
VIZIO monitor is not exactly top-of-the-line :-/ Your 'gamma' strip also looks
correct-- depending on precisely where I place my head in front of my monitor
:-(

The blacks across the top are the most difficult to discern, but I do see them
(I hope it's not just my own wishful thinking, ha.)

I should also mention that your image looks the same-- to the limit of my eyes--
in ALL of my image-viewer apps, at least the ones that will load a TIFF
image--including your own IC app, of course ;-) *That's* a nice discovery.
(Avidemux seem to be a no-go, which was surprising; no proper TIFF demuxer.)
BTW, I find it interesting that the continuous-gray box shows slightly
*different* banding patterns, depending on the app I use. (The banding is minor,
I'm happy to say.)

The ONLY app I'm having an actual problem with is my older (v5.0) Photoshop; the
image loads, but with the message, "The embedded ICC profile cannot be used
because the ICC profile is invalid. Ignoring the profile." You know more about
this stuff than I do; but I'm willing to believe that this is the fault of PS,
not your image. In any case, the image looks correct there as well.


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From: Alain
Subject: Re: Monitor Test-Pattern
Date: 25 Oct 2017 16:10:50
Message: <59f0efca$1@news.povray.org>
Le 17-10-25 à 04:44, Ive a écrit :
> Watch this image in it's original size (1920 x 1080)- otherwise it is 
> completely useless.
> 
> With a decent monitor you should see (from top to bottom):
> 12 "black" boxes.
> A continuous gray-scale without vertical banding.
> 12 "white" boxes.
> 9 "gamma" boxes where the one labeled 2.2 should match the background.
> 
> With a not so decent monitor you are probably unable to distinguish the 
> 4 top-left black boxes and might also see some vertical banding lines 
> within the continuous gray-scale. But if you still see 8 top right 
> "black" boxes and the 12 white ones you are OK - you just didn't want to 
> spend too much money on your viewing device.
> 
> In case you see less than 8 "black" boxes or less than 12 "white" boxes 
> or get strong banding lines you should at least be aware that your 
> monitor is unsuited for judging images and the images you produce with 
> POV-Ray will look very different (most likely quite flat) when viewed by 
> someone with a decent monitor.
> 
> 
> Note that this just tells something about the basic contrast, brightness 
> and gamma properties of the monitor - and nothing about it's ability to 
> render colors properly.
> 
> -Ive

On my HP L1710, I can see all black and white boxes.
The grey band is quite smooth.
The problem is with the gamma boxes. Impossible to get  match: the lined 
part look coloured. Time to look at the colour setting of the OS...


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From: Kenneth
Subject: Re: Monitor Test-Pattern
Date: 25 Oct 2017 18:25:01
Message: <web.59f10e1d41beb38c89df8d30@news.povray.org>
Alain <kua### [at] videotronca> wrote:

> The problem is with the gamma boxes. Impossible to get  match: the lined
> part look coloured. Time to look at the colour setting of the OS...

I'm having the same problem on my new Vizio monitor (and not just with I've's
gamma chart.) My own workaround is to turn the monitor's COLOR all the way to
zero (for a gray-scale view.) That seems to help somewhat-- but I'm not totally
sure if it's a 'valid' method. (I.e., does a lack of color alter the visual
relationship between the gray swatches and the lines? I don't know-- although,
nothing in the chart has any 'color' anyway, so it shouldn't matter.)


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