Hmm ...

I have no problem with PNG, but I have been reluctant to use
it, because I was not sure that everyone could view the images.

Yes, yes ... 1000 images.  But the fact is, there can be as few
as zero images posted to this list every day, and rarely more than
five or six.

Maybe the best idea is to simply go back to making sure that
the attachment size is in the subject line of the e-mail and give
people on the list the choice of downloading or not.  It seems actually
quite rare that someone posts an image greater than 200k to the
list and if it's really big, someone will let them know that it's
causing problems.

Aaron




"Stefan Persson" <azy### [at] teliacom> wrote in message
news:3f4b64e4@news.povray.org...
> The following images was converted with Adobe ImageReady from the original
> PNG-output from POV-Ray.
> I just want to show the difference in size from the 24-bit PNG to the
> "Medium quality" JPG.
> Give or take some decimals the PNG is 209 KiB and the "Medium" JPG is 37,4
> KiB.
> That is roughly a 82% reduction in size with only a slight loss in
quality.
> You could even go for the
> no loss quality (HIGH, 100 or whatever setting your program has) and still
> get a 42% reduction.
> Let's say we post a 100 images and 1000 people download them. With no
> compression
> that is, with my example above, that is something like 20 GiB. Compress
and
> you will get
> 3.5 GiB. Worth the trouble, isn't it?
>
> Of course this is image dependent with nature type of images suffering
less
> than others.
> The "Low quality" JPG was posted just as a reference but even here I have
> problems with spotting
> any severe compression artefacts.
>
> What I'm really after here is that it's not necessary to post a high
quality
> image when you want to
> show a WIP. I can accept a full size image when it's finished but not
> before.
>
> I use a 2Mbit connection so I don't really have a problem, but I think
it's
> for everyones good to reduce the size.
> Like mentioned earlier in the thread, not only it reduces the space on the
> server but it also cuts down traffic.
>
>
> /Stefan
>
>
>
>

Post a reply to this message

"Stefan Persson" <azy### [at] teliacom> wrote in
news:3f4b64e4@news.povray.org: 

> The following images was converted with Adobe ImageReady from the
> original PNG-output from POV-Ray.
> I just want to show the difference in size from the 24-bit PNG to the
> "Medium quality" JPG.
> Give or take some decimals the PNG is 209 KiB and the "Medium" JPG is
> 37,4 KiB.

Thats why I hate PNG files, plus the fact that my news reader does not show 
them on the fly.....

With your test, it shows to others some good reasons to use JPG instead of 
PNG. It's good for slow connection, plus it's good for the server. And for 
the quality loss, it always depend of the source image. But when you know 
how to play with the JPeg format with the right tool, it's not a problem at 
all. 

Ciao!

Mart


-- 
-+======================+-


 bad### [at] hotmailDOTcom
-+======================+-

Post a reply to this message

No, no.. 100 people * 1000 images = 100000 images.. hehe
I was just putting some scale to it.

But why should you post a 200k image when you with a small
effort could post a 40k image? That's my point.

/Stefan

"Aaron Gillies" <no### [at] nospamcom> wrote in message
news:3f4b667b$1@news.povray.org...
> Hmm ...
>
> I have no problem with PNG, but I have been reluctant to use
> it, because I was not sure that everyone could view the images.
>
> Yes, yes ... 1000 images.  But the fact is, there can be as few
> as zero images posted to this list every day, and rarely more than
> five or six.
>
> Maybe the best idea is to simply go back to making sure that
> the attachment size is in the subject line of the e-mail and give
> people on the list the choice of downloading or not.  It seems actually
> quite rare that someone posts an image greater than 200k to the
> list and if it's really big, someone will let them know that it's
> causing problems.
>
> Aaron
>
>
>
>
> "Stefan Persson" <azy### [at] teliacom> wrote in message
> news:3f4b64e4@news.povray.org...
> > The following images was converted with Adobe ImageReady from the
original
> > PNG-output from POV-Ray.
> > I just want to show the difference in size from the 24-bit PNG to the
> > "Medium quality" JPG.
> > Give or take some decimals the PNG is 209 KiB and the "Medium" JPG is
37,4
> > KiB.
> > That is roughly a 82% reduction in size with only a slight loss in
> quality.
> > You could even go for the
> > no loss quality (HIGH, 100 or whatever setting your program has) and
still
> > get a 42% reduction.
> > Let's say we post a 100 images and 1000 people download them. With no
> > compression
> > that is, with my example above, that is something like 20 GiB. Compress
> and
> > you will get
> > 3.5 GiB. Worth the trouble, isn't it?
> >
> > Of course this is image dependent with nature type of images suffering
> less
> > than others.
> > The "Low quality" JPG was posted just as a reference but even here I
have
> > problems with spotting
> > any severe compression artefacts.
> >
> > What I'm really after here is that it's not necessary to post a high
> quality
> > image when you want to
> > show a WIP. I can accept a full size image when it's finished but not
> > before.
> >
> > I use a 2Mbit connection so I don't really have a problem, but I think
> it's
> > for everyones good to reduce the size.
> > Like mentioned earlier in the thread, not only it reduces the space on
the
> > server but it also cuts down traffic.
> >
> >
> > /Stefan
> >
> >
> >
> >
>
>

Post a reply to this message

Quite so :)
But since the browsers don't support TGA or TIFF,  PNG is the
only option if you want to use a alpha channel.

No, GIF is not an option anymore.. ;)

/Stefan

"Martin Belair" <bad### [at] hotmailDOTcom> wrote in message
news:Xns### [at] 204213191226...
> "Stefan Persson" <azy### [at] teliacom> wrote in
> news:3f4b64e4@news.povray.org:
>
> > The following images was converted with Adobe ImageReady from the
> > original PNG-output from POV-Ray.
> > I just want to show the difference in size from the 24-bit PNG to the
> > "Medium quality" JPG.
> > Give or take some decimals the PNG is 209 KiB and the "Medium" JPG is
> > 37,4 KiB.
>
> Thats why I hate PNG files, plus the fact that my news reader does not
show
> them on the fly.....
>
> With your test, it shows to others some good reasons to use JPG instead of
> PNG. It's good for slow connection, plus it's good for the server. And for
> the quality loss, it always depend of the source image. But when you know
> how to play with the JPeg format with the right tool, it's not a problem
at
> all.
>
> Ciao!
>
> Mart
>
>
> --
> -+======================+-


>  bad### [at] hotmailDOTcom
> -+======================+-

Post a reply to this message

"Stefan Persson" <azy### [at] teliacom> wrote in message
news:3f4b70a8$1@news.povray.org...
>
> But why should you post a 200k image when you with a small
> effort could post a 40k image? That's my point.

I understand, except your example here was not right for the subject. I
couldn't see any difference between any of those four images. I don't wear
my eyeglasses most of the time I'm using the computer since I'm nearsighted
and can see well enough to not need them. Although, I can't see perfectly
either so I had to lean closer to the screen to see any imperfections,
possibly because I use a 15" LCD with a 1600x1200 resolution.

Anyway, thing is, without some primary colors there isn't going to be much
distortion. If you had done the same to an image with a bright yellow table
on a red and green checkered floor with blue walls I'd have seen the effects
clearly. [deja vu? like this has all been said before!] And I think this is
the main reason people reject the idea of compressing their renderings much.
I don't know what medium quality equates to in ImageReady but I'm sure it
would make some images look awful, so much so that they wouldn't be as
useful to see anymore.

I agree completely that some tweaking of the Jpeg compression would benefit
everyone, including the person doing the uploading. However, far as that's
concerned, I noticed a while ago that going beyond the conventional
(standard?) Jpeg method can cause a file to be unusable by some Jpeg viewers
so I never attempt it anymore. In fact, I stay away from Jpeg 2000 or the
progressive kind, as well.

I like PNG, actually. I embraced it almost as soon as I first knew about it.
How can anyone not like something that compresses an image file while
leaving it intact? I do concede (for Martin's sake) that for this newsgroup
PNG is not really an acceptable format *unless* Jpeg at highest quality or
least compression still can't do the image justice. Unfortunately, this
seems to be personal judgement which varies a lot and no one can quite lock
down what is best.

While on this topic, I noticed Hugo mention pixel resolution too. Good point
as well, because once you get to a large viewing size the trouble is
two-fold. Being able to see it all at once and compressing to a small enough
file without negatively affecting the appearance. Based on what is typical
here I'd say 800x600 ought to be the usual maximum, with no more than a
300KB download size *after* encoding. I like it when they are less than
that, and get grumpy if encountering megabytes of little or giant images
when I read through povray.binaries.images.
:-)
Afterthought: not exactly the place to fill up with talk about it either.
Heh-heh.

Bob H.

Post a reply to this message

> I understand, except your example here was not right for the subject. I
> couldn't see any difference between any of those four images. I don't wear
> my eyeglasses most of the time I'm using the computer since I'm
nearsighted
> and can see well enough to not need them. Although, I can't see perfectly
> either so I had to lean closer to the screen to see any imperfections,
> possibly because I use a 15" LCD with a 1600x1200 resolution.

My point was that exactly, you can't see any significant difference between
them.
I realised after I posted the images that I should have tagged them in the
picture
so that it would be easier to see which one was which.

> I don't know what medium quality equates to in ImageReady but I'm sure it
> would make some images look awful, so much so that they wouldn't be as
> useful to see anymore.

Well, medium quality in ImageReady is somewhere around 40-50 % compression.
But that is a slider, so in reality it makes the image even smaller.

> I like PNG, actually.

Yes, me too. Mainly because it replaced that awful GIF format.
Though the compression part of the format is not as good as JPG i use
it whenever I can.

> While on this topic, I noticed Hugo mention pixel resolution too. Good
point
> as well, because once you get to a large viewing size the trouble is
> two-fold. Being able to see it all at once and compressing to a small
enough
> file without negatively affecting the appearance. Based on what is typical
> here I'd say 800x600 ought to be the usual maximum, with no more than a
> 300KB download size *after* encoding. I like it when they are less than
> that, and get grumpy if encountering megabytes of little or giant images
> when I read through povray.binaries.images.

Yes, resolution is an issue. I would say that a 17" CRT with 1024x768 is
standard today.
That means that any image larger than 1024x768 is not recommended since it,
like you wrote,
makes it hard to view. If you then consider that we mostly view these images
in somekind of
newsreader with buttons, toolbars and other stuff, 800x600 or less makes it
fit in the
window without having to use sliders. Well, almost anyway.
I didn't say anything about that because that is rather unusual that anyone
posts anything
that large.

/Stefan

Post a reply to this message

>I don't mean to encourage people to put only
>thumbnails here and the real images on their own server or webpage, because
>here the images will last! It's also annoying to visit webforums where
>images have already been taken offline by the people who posted a temporary
>link to them.
>Hugo

Yeah, this is a problem that some users like me have...  I can't use the
news server and cant' use OE or Netscape mail (because of firewall and
proxy connection).  Therefore, I am obliged to put temporary pic in my
webserver, and I agree with you, it is annoying to follow a 404 URL Error
link.  I would prefer to have the possbility to add pictures through the
webpage (may be with a size limitation of 200 Kb max).
Any idea of when we will have the chance to add pic through the website ?
And may be update this sentence : "Attachments: Currently you cannot post
attachments using the web view.  You can always post a message with an
attachment using the regular news server!"

Cheers, Tommy
The 1st African citizen POV member !
==================
http://www.webkenya.com/
Promote Web Development in Africa
WWW = Western or World Wide Web ??

Post a reply to this message

Martin Belair wrote:
> 
> "Stefan Persson" <azy### [at] teliacom> wrote in news:3f476202$1
> @news.povray.org:
> 
> > This is just a humble request:
> 
> Well, I almost agree 100% with you. Excecpt the PNG part: I hate PNG files.
> 
> Another thing to consider is the yEnc format for posting in newsgroup. It is
> very good and becomming wide spread.
> 
> Some newsreader got it embeded in, like Xnews. If you want to know more, go
> there:
> 
> For Yenc encoding: http://www.yenc.org/
> 
> For Xnews: http://xnews.newsguy.com/

I am against yenc encoding for the simple reason that most major news reading
programs do not support it at this time. I refuse to install even more software
just to support another encoding method that has not yet seen wide spread
acceptance. If you want the majority of people who visit this server to view
your work use an encoding method that everyone can see even with their ancient
news readers.

-- 
Ken Tyler

Post a reply to this message

Ken <tyl### [at] pacbellnet> wrote in news:3F4CAEFD.188083B0@pacbell.net:

> 
> Martin Belair wrote:
>> 
>> Another thing to consider is the yEnc format for posting in newsgroup.
>> It is very good and becomming wide spread.
>> 
>> Some newsreader got it embeded in, like Xnews. If you want to know
>> more, go there:


> I am against yenc encoding for the simple reason that most major news
> reading programs do not support it at this time. I refuse to install
> even more software just to support another encoding method that has not
> yet seen wide spread acceptance. If you want the majority of people who
> visit this server to view your work use an encoding method that
> everyone can see even with their ancient news readers.

1- I suggested yEnc as a consideration only.

2- Your explanation sounds like the "Chicken & Egg Story: Who was the 
first to come". If people does not use yEnc encoding, major newsreading 
makers will not see the reason to put it in..... But I understand your 
point, That's why I use Xnews.

3- No offense, but I think we should stop here, we are off topic.

Ciao!

Mart



-- 
-+======================+-


 bad### [at] hotmailDOTcom
-+======================+-

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"Ken" <tyl### [at] pacbellnet> wrote in message
news:3F4CAEFD.188083B0@pacbell.net...
[snip]
> I am against yenc encoding for the simple reason that most major news
reading
> programs do not support it at this time. I refuse to install even more
software
> just to support another encoding method that has not yet seen wide spread
> acceptance. If you want the majority of people who visit this server to
view
> your work use an encoding method that everyone can see even with their
ancient
> news readers.

I totally second that.
This newsgroup keeps all images which means that in 6 months I intend to
look at pictures posted here without having to fight through strange
encoding methods just because simple common sens can't be applied here.
1-DON'T post images over 200 kb
2-DON'T cut a picture in several ones. Chances are if you do, you have
problems with the first point ^__^
3-DON'T use exotic format. Xcf is cool but only readable by The GIMP. Jpeg
can be compressed well and there is the possibility of the link to a
beautiful web page where your work can be presented in all its glory.
You don't know how to convert PNG or BMP into JPEG? Just ask! It's always
cool to help someone.

Change because change is needed, not because people have problem using
common sens!
Chances are that if people don't understand posting rules now, Yenc won't
change that. It will just kick out all the people who came to this server to
see pictures and who have something else to do but to run after decoding
pictures.

Jean-luc who obviously hasn't been raytracing very much these days

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