When I interrupt a, say 640x480, render with Mosaic preview (start 8), there
is a 64-byte PNG file on the disk that wreaks havoc to some of my image
viewers. To name two: Microsoft Photo Editor 3.01 and ACDSee v 3.0.
Both programs lock up. There is no problem with Photoshop 5.5 or MainActor
MainView.
I know that the PNG file is useless and contains no image, but it should not
do such weird thing to some of those programs.
Is there anything to be done or do I have to learn to live with this?

--
Regards,
Sander

Post a reply to this message

On Mon, 24 Jan 2000 22:55:15 +0100, "Sander" <san### [at] stolscom> wrote:

>Is there anything to be done or do I have to learn to live with this?

Try to live with it for now. I have.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

Yep, seemed to me that older image viewers had troubles mostly.  I haven't seen
a unreadable partial render in quite a while.  I use PSP mostly, IrfanView next.
Picture Publisher, I think it was, had trouble though.
Looking at a incomplete Png file you will see something like:

ëPNG

IHDR  
@   _   _O*<   gAMA  _Åna   sBIT_ßO_   "IDATx£_-


And it ends with things like this in it which don't show up unless done
rendering:

IDAT
IEND

So obviously there's a EOF (end of file) sort of tag up with the beginning
information, that's my guess, and some image programs don't need that ending
part then.

Bob

"Peter Popov" <pet### [at] usanet> wrote in message
news:y8+MOPxeC+F35JqvHgERBQ4FeCia@4ax.com...
| On Mon, 24 Jan 2000 22:55:15 +0100, "Sander" <san### [at] stolscom> wrote:
|
| >Is there anything to be done or do I have to learn to live with this?
|
| Try to live with it for now. I have.
|
|
| Peter Popov
| pet### [at] usanet
| ICQ: 15002700

Post a reply to this message

In article <388cca3a@news.povray.org> , "Sander" <san### [at] stolscom> wrote:

> I know that the PNG file is useless and contains no image, but it should not
> do such weird thing to some of those programs.
> Is there anything to be done or do I have to learn to live with this?

No, if a defective or unacceptable file is loaded the programs should
display a proper error message.  Complain to the authors of the programs
that crash on invalid input, not those who generate it :-)


     Thorsten

Post a reply to this message

On Mon, 24 Jan 2000 18:51:04 -0600, "Bob Hughes"
<omn### [at] hotmailcom?subject=PoV-News:> wrote:

>Yep, seemed to me that older image viewers had troubles mostly.

But... but... I am using ACDSee 2.4 , I upgraded to it last month! It
is otherwise a darn good image viewer, even shows .PSD and .PCD but
those broken PNG files wreak havoc at it.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

On Mon, 24 Jan 2000 22:47:41 -0600, "Thorsten Froehlich"
<tho### [at] trfde> wrote:

>No, if a defective or unacceptable file is loaded the programs should
>display a proper error message.  Complain to the authors of the programs
>that crash on invalid input, not those who generate it :-)
>
>
>     Thorsten

These words will haunt you every time someone's POV scene crashes your
Mac :-)


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

Peter Popov wrote:

> On Mon, 24 Jan 2000 18:51:04 -0600, "Bob Hughes"
> <omn### [at] hotmailcom?subject=PoV-News:> wrote:
>
> >Yep, seemed to me that older image viewers had troubles mostly.
>
> But... but... I am using ACDSee 2.4 , I upgraded to it last month! It
> is otherwise a darn good image viewer, even shows .PSD and .PCD but
> those broken PNG files wreak havoc at it.
>

That's bad.

Does it handle the standard broken images?

http://www.cdrom.com/pub/png/pngsuite.html

--
"My new computer's got the clocks, it rocks
But it was obsolete before I opened the box" - W.A.Y.

Post a reply to this message

"Jon A. Cruz" wrote:

> That's bad.
> 
> Does it handle the standard broken images?
> 
> http://www.cdrom.com/pub/png/pngsuite.html

Interesting test suite. Netscape handled them all fine except the last
3 illegal images. IE4 had no problems with any of them but loaded the
images more slowly than Netscape did - I'm guessing 20% slower.

-- 
Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

In article <1UeNOGzt24IcWULQ5zEP29zqcBoh@4ax.com> , Peter Popov 
<pet### [at] usanet>  wrote:

> These words will haunt you every time someone's POV scene crashes your
> Mac :-)

Never happens, I end up in a constantly running low level debugger :-)


         Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message

That doesn't necessarily mean the Png reading is new though  :-)

Bob

"Peter Popov" <pet### [at] usanet> wrote in message
news:00aNOL6MmiDHb8IxIEYPEFGcszi8@4ax.com...
| On Mon, 24 Jan 2000 18:51:04 -0600, "Bob Hughes"
| <omn### [at] hotmailcom?subject=PoV-News:> wrote:
|
| >Yep, seemed to me that older image viewers had troubles mostly.
|
| But... but... I am using ACDSee 2.4 , I upgraded to it last month! It
| is otherwise a darn good image viewer, even shows .PSD and .PCD but
| those broken PNG files wreak havoc at it.
|
|
| Peter Popov
| pet### [at] usanet
| ICQ: 15002700

Post a reply to this message

Hi Thorsten:

I sent 8 e-mails to the makers of ACDSee and I received 10 back from them,
but they don't seem to be prepared to believe that they are at fault. (Their
product does other strange things, by the way). One remark of the respondent
was that "...the defective PNG keeps locking my system...", wich is even
worse than I experience.
I don't have the feeling that there is much progress, although I might be
too impatient.

I quite agree with you that they should provide the solution to this...

--
Regards,
Sander


Thorsten Froehlich <tho### [at] trfde> schreef in berichtnieuws
388d2aed@news.povray.org...
> In article <388cca3a@news.povray.org> , "Sander" <san### [at] stolscom> wrote:
>
> > I know that the PNG file is useless and contains no image, but it should
not
> > do such weird thing to some of those programs.
> > Is there anything to be done or do I have to learn to live with this?
>
> No, if a defective or unacceptable file is loaded the programs should
> display a proper error message.  Complain to the authors of the programs
> that crash on invalid input, not those who generate it :-)
>
>
>      Thorsten

Post a reply to this message

Hi Bob,

I am busily exchanging e-mails with the makers of ACDSee; little result till
now, but that may be too early.
You are right concerning the partial rendering-PNG. I have e.g. the 640x480
4-byte parts, 'gAMA' and ' sBIT' also are present, but no 'IDAT' or 'IEND'.

We'll see what they come up with. As I said: no problems with PS 5.5 or
MainActor 3.04. MS Photo Editor can't handle the defective input..

I feel strengthened in my undertaking to get this straightened out! Thanks.

--
Regards,
Sander


Bob Hughes <omn### [at] hotmailcom?subject=PoV-News:> schreef in
berichtnieuws 388cf38a@news.povray.org...
> Yep, seemed to me that older image viewers had troubles mostly.  I haven't
seen
> a unreadable partial render in quite a while.  I use PSP mostly, IrfanView
next.
> Picture Publisher, I think it was, had trouble though.
> Looking at a incomplete Png file you will see something like:
>
> ëPNG
>
> IHDR  
@   _   _O*<   gAMA  _Å na   sBIT_ßO_   "IDATx£_-

>
> And it ends with things like this in it which don't show up unless done
> rendering:
>
> IDAT
> IEND
>
> So obviously there's a EOF (end of file) sort of tag up with the beginning
> information, that's my guess, and some image programs don't need that
ending
> part then.
>
> Bob
>
> "Peter Popov" <pet### [at] usanet> wrote in message
> news:y8+MOPxeC+F35JqvHgERBQ4FeCia@4ax.com...
> | On Mon, 24 Jan 2000 22:55:15 +0100, "Sander" <san### [at] stolscom> wrote:
> |
> | >Is there anything to be done or do I have to learn to live with this?
> |
> | Try to live with it for now. I have.
> |
> |
> | Peter Popov
> | pet### [at] usanet
> | ICQ: 15002700
>
>

Post a reply to this message

Peter:

the newest version 3.04 isn't any better: so I would advise to wait some
more. I keep on sending messages to ACDSee to try to get them working
harder...

--
Regards,
Sander


Peter Popov <pet### [at] usanet> schreef in berichtnieuws
00aNOL6MmiDHb8IxIEYPEFGcszi8@4ax.com...
> On Mon, 24 Jan 2000 18:51:04 -0600, "Bob Hughes"
> <omn### [at] hotmailcom?subject=PoV-News:> wrote:
>
> >Yep, seemed to me that older image viewers had troubles mostly.
>
> But... but... I am using ACDSee 2.4 , I upgraded to it last month! It
> is otherwise a darn good image viewer, even shows .PSD and .PCD but
> those broken PNG files wreak havoc at it.
>
>
> Peter Popov
> pet### [at] usanet
> ICQ: 15002700

Post a reply to this message

In article <388e0314@news.povray.org> , "Sander" <san### [at] stolscom> wrote:

> I sent 8 e-mails to the makers of ACDSee and I received 10 back from them,
> but they don't seem to be prepared to believe that they are at fault.

Well, the PNGLib (which POV-Ray uses) is the sample implementation of the
PNG standard (not exactly, but practically).  It is the product every other
program has to measure its PNG support at.
And if their code locks up their system it is obviously their program
crashing ... but for them it is of course easy and logical to reject the
blame in that case, they wrote the program ;-)  The best solution is
probably to use another program, if they don't think it is their problem -
and they are then unlikely to fix it soon :-(


      Thorsten

Post a reply to this message

Hmmm, IE 5 here didn't get those 3 "illegal/corrupt" examples.
It also had a CUSS (style-sheet) problem, failing to show backgrounds.  Want to
check your browser too?  Another URL, check here:
http://www.w3.org/Graphics/PNG/inline-alpha-table

Bob

"Ken" <tyl### [at] pacbellnet> wrote in message
news:388D4E0A.C8539A0C@pacbell.net...
|
|
| "Jon A. Cruz" wrote:
|
| > That's bad.
| >
| > Does it handle the standard broken images?
| >
| > http://www.cdrom.com/pub/png/pngsuite.html
|
| Interesting test suite. Netscape handled them all fine except the last
| 3 illegal images. IE4 had no problems with any of them but loaded the
| images more slowly than Netscape did - I'm guessing 20% slower.
|
| --
| Ken Tyler -  1300+ Povray, Graphics, 3D Rendering, and Raytracing Links:
| http://home.pacbell.net/tylereng/index.html http://www.povray.org/links/

Post a reply to this message

There are several other file types I've seen opened even if a partial render the
POV-Ray is apt to do.  Bmp, Tga, Png, have usually been okay like I said before
except for a image program or two I used to use.  Even corrupted Jpg files will
open (most of the time).  Have you tried any other file formats, Sander, in
ACDSee (bmp, tga at least)?  That would narrow it down to the Png part alone.

Bob

"Thorsten Froehlich" <tho### [at] trfde> wrote in message
news:388e0e34@news.povray.org...
| In article <388e0314@news.povray.org> , "Sander" <san### [at] stolscom> wrote:
|
| > I sent 8 e-mails to the makers of ACDSee and I received 10 back from them,
| > but they don't seem to be prepared to believe that they are at fault.
|
| Well, the PNGLib (which POV-Ray uses) is the sample implementation of the
| PNG standard (not exactly, but practically).  It is the product every other
| program has to measure its PNG support at.
| And if their code locks up their system it is obviously their program
| crashing ... but for them it is of course easy and logical to reject the
| blame in that case, they wrote the program ;-)  The best solution is
| probably to use another program, if they don't think it is their problem -
| and they are then unlikely to fix it soon :-(
|
|
|       Thorsten

Post a reply to this message

Bob Hughes wrote in message <388e49c2@news.povray.org>...
>There are several other file types I've seen opened even if a partial
render the
>POV-Ray is apt to do.  Bmp, Tga, Png, have usually been okay like I said
before
>except for a image program or two I used to use.  Even corrupted Jpg files
will
>open (most of the time).  Have you tried any other file formats, Sander, in
>ACDSee (bmp, tga at least)?  That would narrow it down to the Png part
alone.


Try opening the corrupt image file in POV-Ray using the following code,
replacing "garden.png" with the name of your image file to see if LibPNG can
handle the image.  It may be that ACDSee's implimentation of the PNG
standard is at fault, in which case POV-Ray should be able to open the image
correctly, or it may be that ACDSee, like many other programs including
POV-Ray, is having trouble with an image with a width or height of zero.

Mark

global_settings{assumed_gamma 1}

plane{z, 0 pigment{image_map{ png "garden2.png" once interpolate 2 }}
finish{ambient 1.0 diffuse 0}}

camera{
 location <.5,.5,1>
 look_at <.5,.5,0>
 orthographic
 up y
 right x
}

Post a reply to this message

The score is now 14 sent and 13 received emails: I think I'll hang on for a
little while yet. If they are not reacting positively, I will do as you
rightly suggest.
Thanks for caring,
--
Regards,
Sander


Thorsten Froehlich <tho### [at] trfde> schreef in berichtnieuws
388e0e34@news.povray.org...
> In article <388e0314@news.povray.org> , "Sander" <san### [at] stolscom> wrote:
> Well, the PNGLib (which POV-Ray uses) is the sample implementation of the
> PNG standard (not exactly, but practically).  It is the product every
other
> program has to measure its PNG support at.
> And if their code locks up their system it is obviously their program
> crashing ... but for them it is of course easy and logical to reject the
> blame in that case, they wrote the program ;-)  The best solution is
> probably to use another program, if they don't think it is their problem -
> and they are then unlikely to fix it soon :-(
>
>
>       Thorsten

Post a reply to this message

This infamous 64-byte PNG doesn't open in POV-Ray using your code, giving
the output "Error reading PNG image". A regular PNG behaves correctly. What
can I deduce from this?

--
Regards,
Sander


Mark Wagner <mar### [at] gtenet> schreef in berichtnieuws
388e82a2@news.povray.org...
>
> Bob Hughes wrote in message <388e49c2@news.povray.org>...
> Try opening the corrupt image file in POV-Ray using the following code,
> replacing "garden.png" with the name of your image file to see if LibPNG
can
> handle the image.  It may be that ACDSee's implimentation of the PNG
> standard is at fault, in which case POV-Ray should be able to open the
image
> correctly, or it may be that ACDSee, like many other programs including
> POV-Ray, is having trouble with an image with a width or height of zero.
>
> Mark
>
> global_settings{assumed_gamma 1}
>
> plane{z, 0 pigment{image_map{ png "garden2.png" once interpolate 2 }}
> finish{ambient 1.0 diffuse 0}}
>
> camera{
>  location <.5,.5,1>
>  look_at <.5,.5,0>
>  orthographic
>  up y
>  right x
> }
>
>

Post a reply to this message

Let me know if you need some programmers to start browbeating them. Often
companies won't admit problems unless you get on them with people who know what
they're doing. Then again, some companies just don't care.

--
"My new computer's got the clocks, it rocks
But it was obsolete before I opened the box" - W.A.Y.





Sander wrote:

> The score is now 14 sent and 13 received emails: I think I'll hang on for a
> little while yet. If they are not reacting positively, I will do as you
> rightly suggest.
> Thanks for caring,
> --
> Regards,
> Sander
>
> Thorsten Froehlich <tho### [at] trfde> schreef in berichtnieuws
> 388e0e34@news.povray.org...
> > In article <388e0314@news.povray.org> , "Sander" <san### [at] stolscom> wrote:
> > Well, the PNGLib (which POV-Ray uses) is the sample implementation of the
> > PNG standard (not exactly, but practically).  It is the product every
> other
> > program has to measure its PNG support at.
> > And if their code locks up their system it is obviously their program
> > crashing ... but for them it is of course easy and logical to reject the
> > blame in that case, they wrote the program ;-)  The best solution is
> > probably to use another program, if they don't think it is their problem -
> > and they are then unlikely to fix it soon :-(
> >
> >
> >       Thorsten

Post a reply to this message

It means POV can't see it's own partial renders, that's what  :^)
Which in turn means the PngLib isn't up to par either, I guess.

 8^[

Anyhow, I think the output isn't going to matter far as reading it afterward
goes because the lack of a termination part isn't preventing readable files in
other programs.  It must be the "decode", as it were, at fault.
Like I know anything I'm talking about.  Get me out of here!

Bob

"Sander" <san### [at] stolscom> wrote in message news:388eb526@news.povray.org...
| This infamous 64-byte PNG doesn't open in POV-Ray using your code, giving
| the output "Error reading PNG image". A regular PNG behaves correctly. What
| can I deduce from this?
|

Post a reply to this message

On Tue, 25 Jan 2000 19:11:01 -0600, "Bob Hughes"
<omn### [at] hotmailcom?subject=PoV-News:> wrote:

>There are several other file types I've seen opened even if a partial render the
>POV-Ray is apt to do.  Bmp, Tga, Png, have usually been okay like I said before
>except for a image program or two I used to use.  Even corrupted Jpg files will
>open (most of the time).  Have you tried any other file formats, Sander, in
>ACDSee (bmp, tga at least)?  That would narrow it down to the Png part alone.
>
>Bob

From the docs:

"* Support for most popular image formats - BMP, DCX, EMF, GIF
(including animation), IFF, JPEG, KDC, PCD, PCX, PIC, PIX, PNG, PSD,
SGI, TGA, TIFF (including multi-page and 12/16-bit samples) and WMF"

It can also convert to Jpeg, BMP, PCX (including Truecolor) and TIFF.


Peter Popov
pet### [at] usanet
ICQ: 15002700

Post a reply to this message

"Peter Popov" <pet### [at] usanet> wrote in message
news:05qOOKKDi9StpK1fvi3XjbWbf0gJ@4ax.com...
| It can also convert to Jpeg, BMP, PCX (including Truecolor) and TIFF.

Convert those only and not Png files?  Maybe that's the key, Png write.  What a
wild guess though.

Bob

Post a reply to this message

In article <388f428d@news.povray.org> , "Bob Hughes" 
<omn### [at] hotmailcom?subject=PoV-News:> wrote:

> It means POV can't see it's own partial renders, that's what  :^)
> Which in turn means the PngLib isn't up to par either, I guess.

No, you misunderstand something here: The image is empty, so there is no
partial render done yet. Only the last pass of mosaic preview renders is
actually written to a file, the rest is thrown away (but the image file is
opened when mosaic preview is started).  So LibPNG is perfectly fine.


     Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany
e-mail: tho### [at] trfde

Visit POV-Ray on the web: http://mac.povray.org

Post a reply to this message

Thanks for the offer. Should I send you a copy of the e-mail dialogue, or
would that be a breach of something? You could get an idea of how they react
to my complaints, that way. I am *not* a programmer...

--
Regards,
Sander


Jon A. Cruz <jon### [at] geocitiescom> schreef in berichtnieuws
388### [at] geocitiescom...
> Let me know if you need some programmers to start browbeating them. Often
> companies won't admit problems unless you get on them with people who know
what
> they're doing. Then again, some companies just don't care.
>
> --
> "My new computer's got the clocks, it rocks
> But it was obsolete before I opened the box" - W.A.Y.
>

Post a reply to this message

>I am *not* a programmer...

Right, and I'm not a POVer... ;)

Post a reply to this message

Jon A. Cruz <jon### [at] geocitiescom> wrote in <MsgID-suppressed>:

>Let me know if you need some programmers to start browbeating them.
>Often companies won't admit problems unless you get on them with people
>who know what they're doing. Then again, some companies just don't
>care. 

Good good good attitude. I'd like to take you up on that. That's a realy good 
point. I have been struggling solo with the company that produces my registered 
software ThumbsPlus 4, which has a fatal PNG-writing bug in its latest build 
on Win32 (see http://catalpa88.tripod.com/ThumbsBug.html for info on that). 
They say they'll have that fixed for the nest release -- but that doesn't 
address all the old code that they haven't worked on (apparently) for years, 
that doesn't support PNGs (especially color-mapped ones).

If any readers care to go read my page and especially if any use ThumbsPlus, 
please write to the folks at sup### [at] ceriouscom and ceriously ask them (g) to 
pay some cerious attention (ggg) to PNG in their popular application, for a 
change.

  TIA,
     soren andersen

-- 
Using PNG-format images as Web BACKGROUNDs without
"breaking your Site" for silly older browsers:
http://www.wonderstorm.com/techstuff/
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Post a reply to this message

Sander <san### [at] stolscom> wrote in <MsgID-suppressed>:

>Thanks for the offer. Should I send you a copy of the e-mail dialogue, or
>would that be a breach of something? You could get an idea of how they react
>to my complaints, that way. I am *not* a programmer...

Since you asked ..

It would be a serious breach if you posted their replies publically without 
getting prior consent from them. [Treating people as human beings with respect 
is priority number one when you are trying to get someone to listen to you .. 
and that --respect-- is what Netiquette is basically about. But see below.]

Copying the messages to one personal friend is another matter. Lawyers can 
differ (and can go to h___). Common sense: send such communications only 
privately to a person who shares your concerns about an issue; you've been 
corresponding with a *company* (representatives thereof) in their official 
capacity. This relaxes some of the stringency of ethical dictates concerning 
priviledged communications IMO.

If a company representative is abusive to you, all bets are off -- post their 
stuff to public fora freely. THAT's a public service.

  My humble opin,
     soren andersen

-- 
Using PNG-format images as Web BACKGROUNDs without
"breaking your Site" for silly older browsers:
http://www.wonderstorm.com/techstuff/
   ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Post a reply to this message

[This followup was posted to povray.windows and a copy was sent to the 
cited author.]

In article <8F78B0EC4soren2000j@news.povray.org>, 
sor### [at] noYOUknowWHATjunocom says...

> Since you asked ..
> 
> It would be a serious breach if you posted their replies publically without 
> getting prior consent from them. [Treating people as human beings with respect 
> is priority number one when you are trying to get someone to listen to you .. 
> and that --respect-- is what Netiquette is basically about. But see below.]
> 
> Copying the messages to one personal friend is another matter. Lawyers can 
> differ (and can go to h___). Common sense: send such communications only 
> privately to a person who shares your concerns about an issue; you've been 
> corresponding with a *company* (representatives thereof) in their official 
> capacity. This relaxes some of the stringency of ethical dictates concerning 
> priviledged communications IMO.
> 
> If a company representative is abusive to you, all bets are off -- post their 
> stuff to public fora freely. THAT's a public service.

Hi, are you in the know about those 64-byte PNG's? I still have them and 
they still freeze my ACDSee viewer. There has not been a definitive 
recognition of the problem by the makers of ACDSee. But I can live with 
them...

-- 
----------------
Regards,  Sander

Post a reply to this message