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"16-bit" mode.



 
 
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  #171  
Old November 24th 04, 05:22 PM
Timo Autiokari
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Mike Engles wrote:

ftp://ftp.alvyray.com/Acrobat/9_Gamma.pdf


Yes, very good information, from a rather heavy weight professional,
his Bio btw is at: http://alvyray.com/Bio/default.htm Even if it was
written in 1995 it is perfectly valid today (only that in case the
image has an embedded ICC profile we need not to *guess* the transfer
function, ICC color-management was not very popular at that time).

They must be transmitting/recording in at least 18 bit. That is
the bit level that Chris Cox et al say is the minimum necessary
for linear images, without gamma encoding.


No more bits are necessary for digital imaging than what the sensor of
the acquire device is able to provide (according to it's S/N ratio) in
other words there is no need to store pure noise. Say you buy 12 eggs,
then you do not need a trailer truck to bring them home. And these
days the so called pro scanners and pro digital cameras can not reach
even 10-bit. Ther real pro devices (like the EverSmart Supreme ll
scanner that has cooled CCD) can do nearly 12-bit.

And the so called banding issue in 8-bit/c is linear is enormously
exaggerated, it is in fact quite an academic case:Here is an example
from a thread on my forums:

16-bit/ edit:
http://www.aim-dtp.net/aim/temp/sad_...edit-16bit.jpg
8-bit/c edit
http://www.aim-dtp.net/aim/temp/sad_...-edit-8bit.jpg

The original was a linear converted RAW from D60. You can read the
details from the thread:'Linear workflow and 8bit/channel' if you like
to go there. Rather demanding picture in regards to the horrible
banding issue, can you see *any* problems in the 8-bit/c edit?

It does seem that what we have today is two types of digital imaging.
One is the truly scientific one that uses ALL linear data.


Yes, the scientific imaging is done in linear.

The other is a convenient engineering one that delivers the goods
simply, by pre compensating the linear data to display on non linear
displays.


This the _easy solution_ for the ordinary consumers. It is *not* an
engineering issue but a marketing issue.The industry simply needs a
way to sell the digital imaging gadgets to the mass market consumers
without stressing the consumers with the workflow issues.

And the third type of digital imaging is the high end professional
imaging that you see in the better magazines etc. It is still done in
linear domain like it has been done for the past 30 years. For the
very reasons Dr. Alvy Ray Smith lists on his above mentioned memo like
"all computer graphics computations assume linear images", this
includes Photoshop CS also. When the computations are applied over
gamma compensated image data there will be the Gamma Induced Errors.

Timo Autiokari
  #172  
Old November 24th 04, 05:22 PM
Timo Autiokari
external usenet poster
 
Posts: n/a
Default

Mike Engles wrote:

ftp://ftp.alvyray.com/Acrobat/9_Gamma.pdf


Yes, very good information, from a rather heavy weight professional,
his Bio btw is at: http://alvyray.com/Bio/default.htm Even if it was
written in 1995 it is perfectly valid today (only that in case the
image has an embedded ICC profile we need not to *guess* the transfer
function, ICC color-management was not very popular at that time).

They must be transmitting/recording in at least 18 bit. That is
the bit level that Chris Cox et al say is the minimum necessary
for linear images, without gamma encoding.


No more bits are necessary for digital imaging than what the sensor of
the acquire device is able to provide (according to it's S/N ratio) in
other words there is no need to store pure noise. Say you buy 12 eggs,
then you do not need a trailer truck to bring them home. And these
days the so called pro scanners and pro digital cameras can not reach
even 10-bit. Ther real pro devices (like the EverSmart Supreme ll
scanner that has cooled CCD) can do nearly 12-bit.

And the so called banding issue in 8-bit/c is linear is enormously
exaggerated, it is in fact quite an academic case:Here is an example
from a thread on my forums:

16-bit/ edit:
http://www.aim-dtp.net/aim/temp/sad_...edit-16bit.jpg
8-bit/c edit
http://www.aim-dtp.net/aim/temp/sad_...-edit-8bit.jpg

The original was a linear converted RAW from D60. You can read the
details from the thread:'Linear workflow and 8bit/channel' if you like
to go there. Rather demanding picture in regards to the horrible
banding issue, can you see *any* problems in the 8-bit/c edit?

It does seem that what we have today is two types of digital imaging.
One is the truly scientific one that uses ALL linear data.


Yes, the scientific imaging is done in linear.

The other is a convenient engineering one that delivers the goods
simply, by pre compensating the linear data to display on non linear
displays.


This the _easy solution_ for the ordinary consumers. It is *not* an
engineering issue but a marketing issue.The industry simply needs a
way to sell the digital imaging gadgets to the mass market consumers
without stressing the consumers with the workflow issues.

And the third type of digital imaging is the high end professional
imaging that you see in the better magazines etc. It is still done in
linear domain like it has been done for the past 30 years. For the
very reasons Dr. Alvy Ray Smith lists on his above mentioned memo like
"all computer graphics computations assume linear images", this
includes Photoshop CS also. When the computations are applied over
gamma compensated image data there will be the Gamma Induced Errors.

Timo Autiokari
  #173  
Old November 25th 04, 05:50 AM
Chris Cox
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Please do not feed the troll.


In article , Timo Autiokari
wrote nothing useful:
  #174  
Old November 25th 04, 05:50 AM
Chris Cox
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Default

Please do not feed the troll.


In article , Timo Autiokari
wrote nothing useful:
  #175  
Old November 25th 04, 08:57 AM
Mike Russell
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Chris Cox wrote:
Please do not feed the troll.

In article , Timo
Autiokari wrote nothing useful:


I respectfully disagree. Timo's contributions to the group are certainly of
value.

I think he deserves further credit for not responding in kind to some of
those who criticize him personally.
--
Mike Russell
www.curvemeister.com
www.geigy.2y.net


  #176  
Old November 25th 04, 08:57 AM
Mike Russell
external usenet poster
 
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Default

Chris Cox wrote:
Please do not feed the troll.

In article , Timo
Autiokari wrote nothing useful:


I respectfully disagree. Timo's contributions to the group are certainly of
value.

I think he deserves further credit for not responding in kind to some of
those who criticize him personally.
--
Mike Russell
www.curvemeister.com
www.geigy.2y.net


  #177  
Old November 25th 04, 09:21 AM
external usenet poster
 
Posts: n/a
Default

Kibo informs me that Chris Cox stated that:

They're part of the SDK, and always have been.
(and don't get me started on why the SDK isn't free)


*mutter* I can guess.
It'd obviously be inappropriate for you to discuss that issue here, but
if you feel the urge to vent about it, I'd be most interested in
discussing it via email. (This email address will reach me, BTW)

Photoshop RAW is just bytes - no header, no documentation.


Ah. In that case, I should be able to figure the details out for myself.
Much obliged for the hint, Chris.

And if you get a chance to pass on on a message to the genius who
decided to put a price-tag on the SDK (despite the fact that Adobe has
the sense to provide the PostScript, etc doco's for free download),
please inform him/her that that policy has cost them a potential plugin
developer, because I refuse to pay a company money for documentation
that I would need to enhance *their* product. Even *Microsoft* have
finally realised that encouraging 3rd party developers is good business
practice.

--
W
. | ,. w , "Some people are alive only because
\|/ \|/ it is illegal to kill them." Perna condita delenda est
---^----^---------------------------------------------------------------
  #178  
Old November 25th 04, 03:41 PM
external usenet poster
 
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Default

The pot is calling the kettle black again. Chris Cox' behavior was well
documented in this link:
http://www.ledet.com/margulis/How_CM_Failed.pdf

=============================
Is Color Management Rocket Science?

In January, I was e-mailed some tough technical questions from a
gentleman who was having trouble making the upgrade to PS 5. I wondered
why he had not asked them of Adobe. It turned out that he had. Chris
Cox, an Adobe programmer, had responded on-line as follows: “Start by
going to the Adobe web site and reading the PS 5 technical guides (oh,
and get the 5.0.2 update).” The correspondent replied, “I’ve read them
several times and still have the
many questions described (and have 5.0.2).” To that, Mr. Cox’s answer
was, “Well, since they clearly answer the ques-tions you posed, I have
to wonder what’s wrong.”

The answers are not there. And the man Mr. Cox had blown off not only
was a Photoshop instructor with a graduate degree in mathematics but,
get this, a rocket scientist, claiming to have played an important
design role in the launch interface for the Apollo program. The rocket
scientist, having stated these credentials, shot back, “I don’t know
what your problem is. Your first response to my questions showed you
didn’t read my message, which clearly indicates that I had read the
documents you cited. Your second reply, in addition to being totally
insulting, reinforces that you didn’t read the original message as there
are many, many questions not addressed by Adobe. Moreover anyone who
claims that the Adobe documents answer my questions clearly is either an
expert who doesn’t understand the difficulties others have or someone
who doesn’t understand the difficulties of the subject…These are not
straightforward issues...So, Chris, be careful with your snivelling,
ignorant remarks.”

At that point, the two wisely took their conversation off-line, but not
before other readers chimed in. One wrote. “I agree with [the rocket
scientist]. As a Photoshop heavy user since version 1.0, I have been
struggling and struggling with ICC color profiles for a while now and I
just don’t get it! I’VE BEEN TO ADOBE ONLINE....I’m really ****ed at
Adobe. I have ruined—by embedding profiles—a bunch of scans that I don’t
know how I’m going to fix…I’m sure the Adobe engineers had their heads
in the right place, but I’ll be dipped in [doo-doo] if I can get my
scanners, computers and printers to all work together. Sure I can go
back to 4.0, but c’mon—I don’t think that’s the intent of Adobe—to send
people reeling back-wards. Most people will not spend the 8-16 hours
trying to write color profiles and run tons of expensive coated papers
to master this crap. Let’s try to work together to share experiences and
not just patly respond with trite comments.”

You don’t need to be a rocket scientist to agree with that. —DM

Mike Russell wrote:

Chris Cox wrote:
Please do not feed the troll.

In article , Timo
Autiokari wrote nothing useful:


I respectfully disagree. Timo's contributions to the group are certainly of
value.

I think he deserves further credit for not responding in kind to some of
those who criticize him personally.
--
Mike Russell
www.curvemeister.com
www.geigy.2y.net

  #179  
Old November 25th 04, 03:41 PM
external usenet poster
 
Posts: n/a
Default

The pot is calling the kettle black again. Chris Cox' behavior was well
documented in this link:
http://www.ledet.com/margulis/How_CM_Failed.pdf

=============================
Is Color Management Rocket Science?

In January, I was e-mailed some tough technical questions from a
gentleman who was having trouble making the upgrade to PS 5. I wondered
why he had not asked them of Adobe. It turned out that he had. Chris
Cox, an Adobe programmer, had responded on-line as follows: “Start by
going to the Adobe web site and reading the PS 5 technical guides (oh,
and get the 5.0.2 update).” The correspondent replied, “I’ve read them
several times and still have the
many questions described (and have 5.0.2).” To that, Mr. Cox’s answer
was, “Well, since they clearly answer the ques-tions you posed, I have
to wonder what’s wrong.”

The answers are not there. And the man Mr. Cox had blown off not only
was a Photoshop instructor with a graduate degree in mathematics but,
get this, a rocket scientist, claiming to have played an important
design role in the launch interface for the Apollo program. The rocket
scientist, having stated these credentials, shot back, “I don’t know
what your problem is. Your first response to my questions showed you
didn’t read my message, which clearly indicates that I had read the
documents you cited. Your second reply, in addition to being totally
insulting, reinforces that you didn’t read the original message as there
are many, many questions not addressed by Adobe. Moreover anyone who
claims that the Adobe documents answer my questions clearly is either an
expert who doesn’t understand the difficulties others have or someone
who doesn’t understand the difficulties of the subject…These are not
straightforward issues...So, Chris, be careful with your snivelling,
ignorant remarks.”

At that point, the two wisely took their conversation off-line, but not
before other readers chimed in. One wrote. “I agree with [the rocket
scientist]. As a Photoshop heavy user since version 1.0, I have been
struggling and struggling with ICC color profiles for a while now and I
just don’t get it! I’VE BEEN TO ADOBE ONLINE....I’m really ****ed at
Adobe. I have ruined—by embedding profiles—a bunch of scans that I don’t
know how I’m going to fix…I’m sure the Adobe engineers had their heads
in the right place, but I’ll be dipped in [doo-doo] if I can get my
scanners, computers and printers to all work together. Sure I can go
back to 4.0, but c’mon—I don’t think that’s the intent of Adobe—to send
people reeling back-wards. Most people will not spend the 8-16 hours
trying to write color profiles and run tons of expensive coated papers
to master this crap. Let’s try to work together to share experiences and
not just patly respond with trite comments.”

You don’t need to be a rocket scientist to agree with that. —DM

Mike Russell wrote:

Chris Cox wrote:
Please do not feed the troll.

In article , Timo
Autiokari wrote nothing useful:


I respectfully disagree. Timo's contributions to the group are certainly of
value.

I think he deserves further credit for not responding in kind to some of
those who criticize him personally.
--
Mike Russell
www.curvemeister.com
www.geigy.2y.net

  #180  
Old November 25th 04, 07:03 PM
Toby Thain
external usenet poster
 
Posts: n/a
Default

Chris Cox wrote in message ...
...
(and don't get me started on why the SDK isn't free)


Here are my theories:
* so that Adobe can weed out people who want to use the SDK to write
plugin hosts (not to mention other interoperative stuff like parse PSD
format)
* so there is a gate already in place for when the new plugin API is
launched

The timing of the retract was curious, in that it neatly divided
developers from the information they needed to take plugins to OS X
(unless they wanted to pay the money, somersault through the flaming
hoops, wait for their application to be vetted, yadda yadda...)

Shortly before the diktat came down to plug the leak, you can bet
there was muttering in the halls, "Why did we -ever- give it away".

--T


Photoshop RAW is just bytes - no header, no documentation.

Chris

 




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