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Could you actually see photos made from RAW files?



 
 
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  #11  
Old June 1st 09, 03:11 AM posted to rec.photo.digital,uk.rec.photo.misc
Eric Stevens
external usenet poster
 
Posts: 13,611
Default Could you actually see photos made from RAW files?

On Sun, 31 May 2009 16:11:00 -0800, (Floyd L.
Davidson) set out to change the substance of the discussion by
massively editing the article to which he is responding. He is alos
trying to switch the argument from the relationship of the original
image to the RAW file to the relationship of the original image to the
raw data (which is quite different from the content of the RAW file).

Eric Stevens wrote:
On Sun, 31 May 2009 03:10:56 -0800,
(Floyd L.
Davidson) wrote:


--- [Unmarked text deletion by Floyd Davison] -----

When are you going to mark your deletions.


--- [Unmarked text deletion by Floyd Davison] -----


You still haven't figured out how it works, have you.


--- [Unmarked text deletion by Floyd Davison] -----


What do you think I meant by 'statisticsl error limitations'?


You meant to imply that using big words with no meaning
will make it sound like you understand something you
don't. But anyone who does understand the process can
see that you don't.


--- [Unmarked text deletion by Floyd Davison] -----


Yet you claim it is possible to create an image from data that isn't
there!


I have never said any such thing, and see no point in you
making up distortions rather than discussion the topic at
hand.


--- [Unmarked text deletion by Floyd Davison] -----


You said the "source image" is what is projected on the
sensor. Interpolation of course is the method by which
the sensor data is converted to an image format for
viewing.


That's part of what I meant when I wrote of "the rules inherent in the
camera's software".


And you haven't yet figure out that one is the input to while
the other is an output from.


--- [Unmarked text deletion by Floyd Davison] -----


It is quite possible to change the raw data to effect
while balance, but it isn't normally done that way (Nikon,
for example, has hinted that they might be doing exactly
that in hardware).


... and therefore it is a different image. But nevertheless there is
only the one image which can be created from a set of unmodified raw
data.


But clearly that is not true. The raw data set does not
define one single image. It can be interpolated to
produce an image. But the interpolation can be done in
a nearly infinite number of ways, each of which produces
a *different* image. No one way is the _right_ way,
they are all just as correct as the next.

What is changed is the interpolation of the data when
creating an image format. The raw data is not changed,
and the raw file stays exactly the same. The way the
data is manipulated during interpolation changes.


An interpolated data set is a new data set.


--- [Unmarked text deletion by Floyd Davison] -----


The interpolation does not produce a new raw data set.
It produces an unique image.

But only the one JPEG can be created from the RAW data providing the
rules of the transformation do not change.


There is no one set of correct "rules of the
transformation".


--- [Unmarked text deletion by Floyd Davison] -----


False. Every different raw converter design uses a
different set of "rules". Coffin's dcraw.c uses one
set, Nikon uses another, and several other raw
converters are different from both of those.


But they are working on the camera's saved RAW file, not the
relationship between what the sensor sees and the saved RAW file.


Exactly. So why are you claiming otherwise? The raw
data set is not changed. But there are multiple,
correct, different sets of rules used to generate an
exact image from the raw data.


I've been talking about the RAW file from the beginning. So too were
you at that time. Remember "Floyd, I suspect you have been smoking
something which is not good for you. Subject to statistical error
limitations, ... The data in the RAW file can't be restructured to
make a different image without changing the data."

The sensor locations are hardly irrelevant either. As I
said, at least *nine* of them are used to generate each
pixel in the resulting image, and you can be assured the
location is relevant! It isn't one pixel and then 8
other randomly chosen locations... it's a group of 9
(or more).


So?


So please cease this silliness where you claim the
sensor locations are irrelevant.


For any one camera, its just one of the items which go to the
transformation of the image to the RAW file. The sensor locations are
invariant as is the other camera hardware, and the firmware for that
matter.

The signals generated by the sensors are determined by the
rules inherent in the camera's software.

They are determined by rules inherent in the camera's
hardware. The sensor is not manipulated by software
other than clearing it and reading it. A given amount
of light on one sensor locations produces *exactly* the
same output from the sensor regardless of the camera's
software.


I should have said "The signals generated by the sensors are
-interpreted- by the rules inherent in the camera's software". To that
extent they are 'determined'.


I quoted you exactly above. Now you want to change what
you said.


Its called clarification. I haven't changed the meaning.

Regardless, you are still wrong. The signals from the
sensor are interpreted according to *hardware* and the
resulting data set is written to a RAW file format.
That is what is "interpreted" by software.


Have I ever said otherwise? But so what?

As I have already said, there
is a one to one correspondence between the source image and the RAW
file.

You can say that all you like, but it still requires at
least *nine* different sensor locations to generate data
for each pixel of the resulting image. It is not a one
to one relationship.


I see the problem. You misunderstand what I mean by 'one to one'. By
that expression I mean that one imgage transforms into one RAW data
set. Its not as though the transformation entails (say) a quadratic
equation where the one image can give rise to either one of two RAW
data sets. See
http://www.yourdictionary.com/one-to-one

So you now admit that it is not software at all, but a
hard wired hardware transform.


I don't see why you should suddenly try to make that point. In any
case, while I don't know about your camera, I can download an update
for mine. That doesn't sound as though it is all hardware to me.

By next weekend we may force you into writing something
that is clear enough to make some sense.


I assumed a certain level of technical competence from your
background.

You don't have a choice of RAW files for a given image. Nor do
you have a choice of images for a given RAW file.

But you have a choice of an infinite number of resulting
images when the camera raw data is interpolated. None
of them are exactly the same as your "source image" that
was projected onto the sensor.


... and none of them are the image defined by the RAW data. Close,
maybe, but not exact.


That is precisely what I've been trying to get through
your head! Good. Now you can get on with a sane
discusssion of raw data processing.


I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.

The raw data does not define one specific image. When
the data is interpolated there is then an image!


And when that data is interpolated and saved in a RAW file then there
is only the one image. Run that RAW file backwards through the same
transformation and you end back up with the original image of which
there can only be the one.



Eric Stevens
  #12  
Old June 1st 09, 03:58 AM posted to rec.photo.digital,uk.rec.photo.misc
Floyd L. Davidson
external usenet poster
 
Posts: 5,138
Default Could you actually see photos made from RAW files?

Eric Stevens wrote:
On Sun, 31 May 2009 16:11:00 -0800, (Floyd L.
Davidson) set out to change the substance of the discussion by
massively editing the article to which he is responding. He is alos
trying to switch the argument from the relationship of the original
image to the RAW file to the relationship of the original image to the
raw data (which is quite different from the content of the RAW file).


You actually are that dense!

Exactly. So why are you claiming otherwise? The raw
data set is not changed. But there are multiple,
correct, different sets of rules used to generate an
exact image from the raw data.


I've been talking about the RAW file from the beginning. So too were
you at that time. Remember "Floyd, I suspect you have been smoking
something which is not good for you. Subject to statistical error
limitations, ... The data in the RAW file can't be restructured to
make a different image without changing the data."


The data in the raw file is not restructured.

Your nonsense is still nonsense.

The sensor locations are hardly irrelevant either. As I
said, at least *nine* of them are used to generate each
pixel in the resulting image, and you can be assured the
location is relevant! It isn't one pixel and then 8
other randomly chosen locations... it's a group of 9
(or more).

So?


So please cease this silliness where you claim the
sensor locations are irrelevant.


For any one camera, its just one of the items which go to the
transformation of the image to the RAW file. The sensor locations are
invariant as is the other camera hardware, and the firmware for that
matter.


So what are you trying to say? The sensor locations *are*
relevant!

You do understand that "firmware" is where the
"software" is, right?

I'm getting the idea that you have a list of buzz words; but no
idea what any of it means.

The signals generated by the sensors are determined by the
rules inherent in the camera's software.


That statement is blatantly false.

They are determined by rules inherent in the camera's
hardware. The sensor is not manipulated by software
other than clearing it and reading it. A given amount
of light on one sensor locations produces *exactly* the
same output from the sensor regardless of the camera's
software.

I should have said "The signals generated by the sensors are
-interpreted- by the rules inherent in the camera's software". To that
extent they are 'determined'.


This statement is blatantly *different*.

I quoted you exactly above. Now you want to change what
you said.


Its called clarification. I haven't changed the meaning.


They you don't understand what you said.

Regardless, you are still wrong. The signals from the
sensor are interpreted according to *hardware* and the
resulting data set is written to a RAW file format.
That is what is "interpreted" by software.


Have I ever said otherwise? But so what?


You did say otherwise. Quoted above.

So you now admit that it is not software at all, but a
hard wired hardware transform.


I don't see why you should suddenly try to make that point. In any
case, while I don't know about your camera, I can download an update
for mine. That doesn't sound as though it is all hardware to me.


You aren't going to download an update that changes how the
hardware processes sensor data to generate the "raw data". It's
hard wired. The sensor output is *analog*, and the digital
data is generated by a series of *hardware* devices. About all
the software does is switch the hardware on and off!

I assumed a certain level of technical competence from your
background.


That is correct. A few decades working with digital data,
transmission systems (which is what the hardware between the
sensor and the CF card is) and little things like that... :-)

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.


The raw data saved in the RAW file is not interpolated.

The raw data does not define one specific image. When
the data is interpolated there is then an image!


And when that data is interpolated and saved in a RAW file then there


That does not happen. (Except of course for the various
thumbnail JPEG images that are embedded in most RAW files.)

is only the one image. Run that RAW file backwards through the same
transformation and you end back up with the original image of which
there can only be the one.


It is a one way process and it cannot be precisely
reversed. If for no other reason than what is called
quantization distortion... However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

  #13  
Old June 1st 09, 05:28 AM posted to rec.photo.digital,uk.rec.photo.misc
Eric Stevens
external usenet poster
 
Posts: 13,611
Default Could you actually see photos made from RAW files?

On Sun, 31 May 2009 18:58:46 -0800, (Floyd L.
Davidson) wrote:

Eric Stevens wrote:
On Sun, 31 May 2009 16:11:00 -0800,
(Floyd L.
Davidson) set out to change the substance of the discussion by
massively editing the article to which he is responding. He is alos
trying to switch the argument from the relationship of the original
image to the RAW file to the relationship of the original image to the
raw data (which is quite different from the content of the RAW file).


You actually are that dense!


I read the words. I even quoted them down below. In fact, because you
have (surreptitiously) snipped an awful lot of what follows, its only
two paragraphs down.

Exactly. So why are you claiming otherwise? The raw
data set is not changed. But there are multiple,
correct, different sets of rules used to generate an
exact image from the raw data.


I've been talking about the RAW file from the beginning. So too were
you at that time. Remember "Floyd, I suspect you have been smoking
something which is not good for you. Subject to statistical error
limitations, ... The data in the RAW file can't be restructured to
make a different image without changing the data."


The data in the raw file is not restructured.

Your nonsense is still nonsense.


How can you relate a different image in the camera to the one RAW
file?

The sensor locations are hardly irrelevant either. As I
said, at least *nine* of them are used to generate each
pixel in the resulting image, and you can be assured the
location is relevant! It isn't one pixel and then 8
other randomly chosen locations... it's a group of 9
(or more).

So?

So please cease this silliness where you claim the
sensor locations are irrelevant.


For any one camera, its just one of the items which go to the
transformation of the image to the RAW file. The sensor locations are
invariant as is the other camera hardware, and the firmware for that
matter.


So what are you trying to say? The sensor locations *are*
relevant!


Only as part of the transformation algorithm.

You do understand that "firmware" is where the
"software" is, right?

I'm getting the idea that you have a list of buzz words; but no
idea what any of it means.


One of us doesn't seem to.

The signals generated by the sensors are determined by the
rules inherent in the camera's software.


That statement is blatantly false.


You made it false by chopping out the text around it which made clear
what I was talking about. For the benefit of others I had written:

"The sensor locations are irrelevant. The RAW data is derived
from the sensors by rules which are determined by the
manufacturer of the camera. The signals generated by the
sensors are determined by the rules inherent in the camera's
software. As I have already said, there is a one to one
correspondence between the source image and the RAW
file. You don't have a choice of RAW files for a given image.
Nor do you have a choice of images for a given RAW file".

They are determined by rules inherent in the camera's
hardware. The sensor is not manipulated by software
other than clearing it and reading it. A given amount
of light on one sensor locations produces *exactly* the
same output from the sensor regardless of the camera's
software.

I should have said "The signals generated by the sensors are
-interpreted- by the rules inherent in the camera's software". To that
extent they are 'determined'.


This statement is blatantly *different*.

I quoted you exactly above. Now you want to change what
you said.


Its called clarification. I haven't changed the meaning.


They you don't understand what you said.


I thought that was your problem. That's why I clarified it.

Regardless, you are still wrong. The signals from the
sensor are interpreted according to *hardware* and the
resulting data set is written to a RAW file format.
That is what is "interpreted" by software.


Have I ever said otherwise? But so what?


You did say otherwise. Quoted above.


I can't see where. Someone must have accidentally deleted it.

So you now admit that it is not software at all, but a
hard wired hardware transform.


I don't see why you should suddenly try to make that point. In any
case, while I don't know about your camera, I can download an update
for mine. That doesn't sound as though it is all hardware to me.


You aren't going to download an update that changes how the
hardware processes sensor data to generate the "raw data". It's
hard wired. The sensor output is *analog*, and the digital
data is generated by a series of *hardware* devices. About all
the software does is switch the hardware on and off!


First we are not talking about the RAW data. We (should) always have
been talking about the RAW data file. Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.

I assumed a certain level of technical competence from your
background.


That is correct. A few decades working with digital data,
transmission systems (which is what the hardware between the
sensor and the CF card is) and little things like that... :-)


I thought you were a psychologist.

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.


The raw data saved in the RAW file is not interpolated.


See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."

The raw data does not define one specific image. When
the data is interpolated there is then an image!


And when that data is interpolated and saved in a RAW file then there


That does not happen. (Except of course for the various
thumbnail JPEG images that are embedded in most RAW files.)


Umm...

is only the one image. Run that RAW file backwards through the same
transformation and you end back up with the original image of which
there can only be the one.


It is a one way process and it cannot be precisely
reversed. If for no other reason than what is called
quantization distortion...


Don't come the technical heavy with me! After all, you are the one who
claimed to not understand what I meant by "statistical error
limitations".

However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.


HOW DO I MAKE IT CLEAR THAT FROM THE BEGINNING WE HAVE BEEN TALKING
ABOUT THE RELATIONSHIP BETWEEN THE ORIGINAL IMAGE ON THE SENSOR AND
THE 'RAW' FILE.

Sorry for shouting but I've said the above several times, I've quoted
from the original articls, and you still keep trying to switch to
conversion from RAW to JPG. That's an entirely different question.



Eric Stevens
  #14  
Old June 1st 09, 08:44 AM posted to rec.photo.digital,uk.rec.photo.misc
Floyd L. Davidson
external usenet poster
 
Posts: 5,138
Default Could you actually see photos made from RAW files?

Eric Stevens wrote:
You actually are that dense!


I read the words. I even quoted them down below. In fact, because you
have (surreptitiously) snipped an awful lot of what follows, its only
two paragraphs down.


You still think that I should quote your entire silly article.
That is *dense*.

So what are you trying to say? The sensor locations *are*
relevant!


Only as part of the transformation algorithm.


No **** Sherlock. Which is to say, yes they are and
your statements otherwise were mistaken from the start.

You do understand that "firmware" is where the
"software" is, right?

I'm getting the idea that you have a list of buzz words; but no
idea what any of it means.


One of us doesn't seem to.


And it isn't at all difficult to determine which that
would be, Eric. Try, for example, to get a grip on
"interpolation" before you continue on with this
discussion. Try learning where software is used in the
data flow, and where it is a purely hardward process.

You made it false by chopping out the text around it which made clear
what I was talking about. For the benefit of others I had written:

"The sensor locations are irrelevant. The RAW data is derived
from the sensors by rules which are determined by the
manufacturer of the camera. The signals generated by the
sensors are determined by the rules inherent in the camera's
software. As I have already said, there is a one to one
correspondence between the source image and the RAW
file. You don't have a choice of RAW files for a given image.
Nor do you have a choice of images for a given RAW file".


Yes, and your statement is still false. Explaining a
false statement doesn't change the fact that it is
false.

False: "sensor locations are irrelevant"

False: "signals generated by the sensors are
determined by ... software"

False: "Nor do you have a choicce of images
for a given RAW file"

Nice paragraph.

Regardless, you are still wrong. The signals from the
sensor are interpreted according to *hardware* and the
resulting data set is written to a RAW file format.
That is what is "interpreted" by software.

Have I ever said otherwise? But so what?


You did say otherwise. Quoted above.


I can't see where. Someone must have accidentally deleted it.


Now, if you missed where you'd said it before, take a look at
what you just repeated. See it now? It's wrong...

So you now admit that it is not software at all, but a
hard wired hardware transform.

I don't see why you should suddenly try to make that point. In any
case, while I don't know about your camera, I can download an update
for mine. That doesn't sound as though it is all hardware to me.


You aren't going to download an update that changes how the
hardware processes sensor data to generate the "raw data". It's
hard wired. The sensor output is *analog*, and the digital
data is generated by a series of *hardware* devices. About all
the software does is switch the hardware on and off!


First we are not talking about the RAW data. We (should) always have
been talking about the RAW data file.


The "RAW data file" is merely a file containing the
camera raw data. The only part of the file that relates
to the image is the data it contains. Which is to say
that we *are* talking about the "RAW data", even if you
want to call if a "RAW data file". It's the same data
either way.

Note that "sensor data", in the context of this
discussion, would be the analog data directly read from
the sensor (though in other contexts those words might
be used to mean the digital data too). "RAW data"
clearly must refer to the digital data that goes into
the "RAW file". That is the only place where "RAW" is
used. (And I often use "raw", simply because "RAW"
is grammatically incorrect. They are the same.)

Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.


Nice try, but I just read the release notes for Nikon's
upgraded firmware for the D300, and saw exactly *nothing*
like what you are saying.

Provide details, and be specific.

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.


The raw data saved in the RAW file is not interpolated.


See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."


Didn't you read what that paragraph says????

Are you unable to determine that the "after
interpolation" is refering not to generation of data
that goes into the RAW file, but rather what is done
with data *from* the RAW file in order to make an image
(such as TIFF or JPEG). That is what "image pixels" means.

The data saved in the RAW file has not yet been
interpolated, and when it is interpolated it is *not*
saved in the RAW file, and is no longer considered "raw"
data.

The raw data does not define one specific image. When
the data is interpolated there is then an image!

And when that data is interpolated and saved in a RAW file then there


That does not happen. (Except of course for the various
thumbnail JPEG images that are embedded in most RAW files.)


Umm...


Ummmm..... see above.

is only the one image. Run that RAW file backwards through the same
transformation and you end back up with the original image of which
there can only be the one.


It is a one way process and it cannot be precisely
reversed. If for no other reason than what is called
quantization distortion...


Don't come the technical heavy with me! After all, you are the one who
claimed to not understand what I meant by "statistical error
limitations".


I know exactly what *you* meant by that. The point was
that your statement was wrong, and you threw in
nonsensical statement to make it appear to have
significance. Statistical error limitations indeed!

However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.


HOW DO I MAKE IT CLEAR THAT FROM THE BEGINNING WE HAVE BEEN TALKING
ABOUT THE RELATIONSHIP BETWEEN THE ORIGINAL IMAGE ON THE SENSOR AND
THE 'RAW' FILE.


Then don't talk about interpolation and other software processing
of the raw data, all of which takes place on data *after* it is
placed in the RAW file.

Sorry for shouting but I've said the above several times,


And then you talk about something different. You don't
seem to have even a meager knowledge of the data flow.

I've quoted
from the original articls, and you still keep trying to switch to
conversion from RAW to JPG. That's an entirely different question.


Then stop talking about processing the RAW data to make an image.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)
  #15  
Old June 1st 09, 10:45 AM posted to rec.photo.digital,uk.rec.photo.misc
Eric Stevens
external usenet poster
 
Posts: 13,611
Default Could you actually see photos made from RAW files?

On Sun, 31 May 2009 23:44:15 -0800, (Floyd L.
Davidson) wrote:

Eric Stevens wrote:
You actually are that dense!


I read the words. I even quoted them down below. In fact, because you
have (surreptitiously) snipped an awful lot of what follows, its only
two paragraphs down.


You still think that I should quote your entire silly article.
That is *dense*.


Hell No! You should cut and paste my article to make it mean whatever
you would like it to mean. :-(

So what are you trying to say? The sensor locations *are*
relevant!


Only as part of the transformation algorithm.


No **** Sherlock. Which is to say, yes they are and
your statements otherwise were mistaken from the start.

You do understand that "firmware" is where the
"software" is, right?

I'm getting the idea that you have a list of buzz words; but no
idea what any of it means.


One of us doesn't seem to.


And it isn't at all difficult to determine which that
would be, Eric. Try, for example, to get a grip on
"interpolation" before you continue on with this
discussion. Try learning where software is used in the
data flow, and where it is a purely hardward process.


YOU try looking up interpolation in the context of the Bayer process.
I've done it once already for you. It didn't seem to ring a bell, even
the first time.

You made it false by chopping out the text around it which made clear
what I was talking about. For the benefit of others I had written:

"The sensor locations are irrelevant. The RAW data is derived
from the sensors by rules which are determined by the
manufacturer of the camera. The signals generated by the
sensors are determined by the rules inherent in the camera's
software. As I have already said, there is a one to one
correspondence between the source image and the RAW
file. You don't have a choice of RAW files for a given image.
Nor do you have a choice of images for a given RAW file".


Yes, and your statement is still false. Explaining a
false statement doesn't change the fact that it is
false.

False: "sensor locations are irrelevant"

False: "signals generated by the sensors are
determined by ... software"

False: "Nor do you have a choicce of images
for a given RAW file"


Look up Bayer interpolation.

Nice paragraph.

Regardless, you are still wrong. The signals from the
sensor are interpreted according to *hardware* and the
resulting data set is written to a RAW file format.
That is what is "interpreted" by software.

Have I ever said otherwise? But so what?

You did say otherwise. Quoted above.


I can't see where. Someone must have accidentally deleted it.


Now, if you missed where you'd said it before, take a look at
what you just repeated. See it now? It's wrong...

So you now admit that it is not software at all, but a
hard wired hardware transform.

I don't see why you should suddenly try to make that point. In any
case, while I don't know about your camera, I can download an update
for mine. That doesn't sound as though it is all hardware to me.

You aren't going to download an update that changes how the
hardware processes sensor data to generate the "raw data". It's
hard wired. The sensor output is *analog*, and the digital
data is generated by a series of *hardware* devices. About all
the software does is switch the hardware on and off!


First we are not talking about the RAW data. We (should) always have
been talking about the RAW data file.


The "RAW data file" is merely a file containing the
camera raw data. The only part of the file that relates
to the image is the data it contains. Which is to say
that we *are* talking about the "RAW data", even if you
want to call if a "RAW data file". It's the same data
either way.


Nope. What comes out of the sensor is not what is saved in the RAW
file. There is a transformation involved.

Note that "sensor data", in the context of this
discussion, would be the analog data directly read from
the sensor ....


.... what analog data?

...(though in other contexts those words might
be used to mean the digital data too).


I see you have had second thoughts.

"RAW data"
clearly must refer to the digital data that goes into
the "RAW file". That is the only place where "RAW" is
used. (And I often use "raw", simply because "RAW"
is grammatically incorrect. They are the same.)

Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.


Nice try, but I just read the release notes for Nikon's
upgraded firmware for the D300, and saw exactly *nothing*
like what you are saying.

Provide details, and be specific.

What do you make of:

. Image quality: NEF (RAW ) + JPEG
. NEF (RAW) recording: Lossless compressed or Compressed
. Image size: S or M

That sounds like a change in the way raw data from the sensors have
been interpreted and saved to the RAW file.

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.

The raw data saved in the RAW file is not interpolated.


See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."


Didn't you read what that paragraph says????

Are you unable to determine that the "after
interpolation" is refering not to generation of data
that goes into the RAW file, but rather what is done
with data *from* the RAW file in order to make an image
(such as TIFF or JPEG). That is what "image pixels" means.


Haw! You really don't understand what Bayer interpolation is all
about.

The data saved in the RAW file has not yet been
interpolated, ....


How else do you reckon it is derived from the Bayer mosaic?

... and when it is interpolated it is *not*
saved in the RAW file, and is no longer considered "raw"
data.


Well, at least you understand that much.

The raw data does not define one specific image. When
the data is interpolated there is then an image!

And when that data is interpolated and saved in a RAW file then there

That does not happen. (Except of course for the various
thumbnail JPEG images that are embedded in most RAW files.)


Umm...


Ummmm..... see above.

is only the one image. Run that RAW file backwards through the same
transformation and you end back up with the original image of which
there can only be the one.

It is a one way process and it cannot be precisely
reversed. If for no other reason than what is called
quantization distortion...


Don't come the technical heavy with me! After all, you are the one who
claimed to not understand what I meant by "statistical error
limitations".


I know exactly what *you* meant by that. The point was
that your statement was wrong, and you threw in
nonsensical statement to make it appear to have
significance. Statistical error limitations indeed!


My oath there are statistical error limitations! That you call it
'quantization distortion' doesn't change the fact.

However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.


HOW DO I MAKE IT CLEAR THAT FROM THE BEGINNING WE HAVE BEEN TALKING
ABOUT THE RELATIONSHIP BETWEEN THE ORIGINAL IMAGE ON THE SENSOR AND
THE 'RAW' FILE.


Then don't talk about interpolation and other software processing
of the raw data, all of which takes place on data *after* it is
placed in the RAW file.


Dingbat - interpolation is an assential part of going from the Bayer
array to the RAW data file. Please don't continue to pretend
otherwise.

Sorry for shouting but I've said the above several times,


And then you talk about something different. You don't
seem to have even a meager knowledge of the data flow.

I've quoted
from the original articls, and you still keep trying to switch to
conversion from RAW to JPG. That's an entirely different question.


Then stop talking about processing the RAW data to make an image.


I haven't been. If anything I've been talking about working backwards
from the RAW data file to reconstruct the original image.



Eric Stevens
  #16  
Old June 1st 09, 11:12 AM posted to rec.photo.digital,uk.rec.photo.misc
nospam
external usenet poster
 
Posts: 24,165
Default Could you actually see photos made from RAW files?

In article , Eric Stevens
wrote:

The "RAW data file" is merely a file containing the
camera raw data. The only part of the file that relates
to the image is the data it contains. Which is to say
that we *are* talking about the "RAW data", even if you
want to call if a "RAW data file". It's the same data
either way.


Nope. What comes out of the sensor is not what is saved in the RAW
file. There is a transformation involved.


what type of transformation and from what to what?

depending on the camera, there may be minor changes such as analog
white balance or noise reduction, but for all intents the data in the
raw file *is* the data off the sensor, at least with bayer sensors.

Note that "sensor data", in the context of this
discussion, would be the analog data directly read from
the sensor ....


... what analog data?


from the sensor, before the a/d converter.

Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.


Nice try, but I just read the release notes for Nikon's
upgraded firmware for the D300, and saw exactly *nothing*
like what you are saying.

Provide details, and be specific.

What do you make of:

. Image quality: NEF (RAW ) + JPEG
. NEF (RAW) recording: Lossless compressed or Compressed
. Image size: S or M

That sounds like a change in the way raw data from the sensors have
been interpreted and saved to the RAW file.


no it doesn't. the first is embedding the jpeg in addition to the raw
data and the second is how it's compressed. the third is for the size
of the jpeg file. raw files are always full size, with canon's sraw
being an exception (and since this is a nikon d300, not applicable).

I wouldn't argue with you over what you have just said but I would
like to point out that this discussion has been about the interpolated
data saved in the RAW file.

The raw data saved in the RAW file is not interpolated.

See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."


Didn't you read what that paragraph says????

Are you unable to determine that the "after
interpolation" is refering not to generation of data
that goes into the RAW file, but rather what is done
with data *from* the RAW file in order to make an image
(such as TIFF or JPEG). That is what "image pixels" means.


Haw! You really don't understand what Bayer interpolation is all
about.


if anyone doesn't understand it, it's you. nowhere in what *you*
quoted says the data in the raw *file* is interpolated.

the interpolation is done in the raw converter on the computer, long
after the raw file has been created.

The data saved in the RAW file has not yet been
interpolated, ....


How else do you reckon it is derived from the Bayer mosaic?


the data in the raw file is *before* the interpolation is done to
demosaic the image.

... and when it is interpolated it is *not*
saved in the RAW file, and is no longer considered "raw"
data.


Well, at least you understand that much.


odd, because that contradicts what you've been saying.

However, in addition to that
the JPEG image which results from interpolation simply
does not contain anything like the full amount of
information that was in the RAW file's data. You cannot
reverse the process.

HOW DO I MAKE IT CLEAR THAT FROM THE BEGINNING WE HAVE BEEN TALKING
ABOUT THE RELATIONSHIP BETWEEN THE ORIGINAL IMAGE ON THE SENSOR AND
THE 'RAW' FILE.


Then don't talk about interpolation and other software processing
of the raw data, all of which takes place on data *after* it is
placed in the RAW file.


Dingbat - interpolation is an assential part of going from the Bayer
array to the RAW data file. Please don't continue to pretend
otherwise.


no need to pretend otherwise since that's totally incorrect.

I've quoted
from the original articls, and you still keep trying to switch to
conversion from RAW to JPG. That's an entirely different question.


Then stop talking about processing the RAW data to make an image.


I haven't been. If anything I've been talking about working backwards
from the RAW data file to reconstruct the original image.


that doesn't make any sense.
  #17  
Old June 1st 09, 11:45 AM posted to rec.photo.digital,uk.rec.photo.misc
Floyd L. Davidson
external usenet poster
 
Posts: 5,138
Default Could you actually see photos made from RAW files?

Eric Stevens wrote:
On Sun, 31 May 2009 23:44:15 -0800, (Floyd L.
Davidson) wrote:

Eric Stevens wrote:
You actually are that dense!

I read the words. I even quoted them down below. In fact, because you
have (surreptitiously) snipped an awful lot of what follows, its only
two paragraphs down.


You still think that I should quote your entire silly article.
That is *dense*.


Hell No! You should cut and paste my article to make it mean whatever
you would like it to mean. :-(


I have not changed a single character of the silly
things you've written, and in no way have I ever changed
the meaning of a single sentence. Please do not blame
me for what you write!

Again though, it's time that you learned that proper
Usenet netiquette is to trim the quoted text to only that
require for context. I do that. You don't.

And it isn't at all difficult to determine which that
would be, Eric. Try, for example, to get a grip on
"interpolation" before you continue on with this
discussion. Try learning where software is used in the
data flow, and where it is a purely hardward process.


YOU try looking up interpolation in the context of the Bayer process.
I've done it once already for you. It didn't seem to ring a bell, even
the first time.


Such as where you quoted Wikipedia, and didn't
understand what it said! As noted just 5 or so lines
above, learn something about the data flow.

You made it false by chopping out the text around it which made clear
what I was talking about. For the benefit of others I had written:

"The sensor locations are irrelevant. The RAW data is derived
from the sensors by rules which are determined by the
manufacturer of the camera. The signals generated by the
sensors are determined by the rules inherent in the camera's
software. As I have already said, there is a one to one
correspondence between the source image and the RAW
file. You don't have a choice of RAW files for a given image.
Nor do you have a choice of images for a given RAW file".


Yes, and your statement is still false. Explaining a
false statement doesn't change the fact that it is
false.

False: "sensor locations are irrelevant"

False: "signals generated by the sensors are
determined by ... software"

False: "Nor do you have a choicce of images
for a given RAW file"


Look up Bayer interpolation.


And you'll find: 1) that sensor locations are relevant; 2) that
the signals generated by the sensors are not determined by
software, as that is a purely hardware domain; 3) that
the RAW file is data which has not been interpolated, and
when it is interpolated there are many choices for a given
set of raw data.

Note that interpolation is not what generates the data
in a "RAW file", it is what generates a TIFF or JPEG
formatted image file. Remember that you wanted to only
talk about RAW data, not the JPEG... but here you are
once again discussing the processing of data to produce
an image file...

Hmmm... right here it is:

First we are not talking about the RAW data. We (should) always have
been talking about the RAW data file.


The "RAW data file" is merely a file containing the
camera raw data. The only part of the file that relates
to the image is the data it contains. Which is to say
that we *are* talking about the "RAW data", even if you
want to call if a "RAW data file". It's the same data
either way.


Nope. What comes out of the sensor is not what is saved in the RAW
file. There is a transformation involved.


That is a hardware transformation, not one that is
called interpolation and not one that is done with
software.

Note that "sensor data", in the context of this
discussion, would be the analog data directly read from
the sensor ....


... what analog data?


The sensor is an analog device.

...(though in other contexts those words might
be used to mean the digital data too).


I see you have had second thoughts.


Neither of us has used it in that context, and since you
have repeatedly confused various parts of the data flow
it is absolutely essential to differentiate the analog
sensor data from the digital data output of the ADC.

In many contexts the sensor, the ISO amplifiers, and the
ADC are all considered "the sensor" in order to simplify
a discussion that really does not involve them other than
as a unit. This is clearly not one of those discussions.

"RAW data"
clearly must refer to the digital data that goes into
the "RAW file". That is the only place where "RAW" is
used. (And I often use "raw", simply because "RAW"
is grammatically incorrect. They are the same.)

Second, in the case of the Nikon
D300 the update has changed the way in which the raw data from the
sensors have been interpreted and saved to the RAW file.


Nice try, but I just read the release notes for Nikon's
upgraded firmware for the D300, and saw exactly *nothing*
like what you are saying.

Provide details, and be specific.

What do you make of:

. Image quality: NEF (RAW ) + JPEG
. NEF (RAW) recording: Lossless compressed or Compressed
. Image size: S or M

That sounds like a change in the way raw data from the sensors have
been interpreted and saved to the RAW file.


It looks like the specifications from the User Manual to
me. Where's the change?

Granted though that they *could* upgrade the firmware
with a different RAW file data format. I can see how
*you* would call that a change in the data, but in fact
it isn't. It is a change in the way the data is
represented and stored in the file, but the *value* of
the data remains the same. Which is to say that the
data values which a raw converter will use for
interpolation will not be different. That processing
is merely encoding of values, not a form of processing
that affects the data or the images that are eventually
produced.

The raw data saved in the RAW file is not interpolated.

See the last line of ...
http://en.wikipedia.org/wiki/Bayer_filter

"Bryce Bayer's patent called the green photosensors
luminance-sensitive elements and the red and blue ones
chrominance-sensitive elements. He used twice as many
green elements as red or blue to mimic the human eye's
greater resolving power with green light. These elements
are referred to as sensor elements, sensels, pixel sensors,
or simply pixels; sample values sensed by them, after
interpolation, become image pixels."


Didn't you read what that paragraph says????

Are you unable to determine that the "after
interpolation" is refering not to generation of data
that goes into the RAW file, but rather what is done
with data *from* the RAW file in order to make an image
(such as TIFF or JPEG). That is what "image pixels" means.


Haw! You really don't understand what Bayer interpolation is all
about.


Haw! You have clearly misread the text you quoted!
Hilarious again!

The RAW data file does not contain data that has been
interpolated (de-mosaiced).

The data saved in the RAW file has not yet been
interpolated, ....


How else do you reckon it is derived from the Bayer mosaic?


The raw data in the RAW file is derived using a rather
standard Analog-to-Digital Converter. Between the
sensor and the ADC there are analog amplifiers with
programmable gain, which are used to set the ISO
sensitivity.

The RAW file contains data that has not yet been
de-mosaiced. That is a software process that is used to
generate an image format, such as JPEG. (Remember that?
The process you didn't want to be discussed?)

... and when it is interpolated it is *not*
saved in the RAW file, and is no longer considered "raw"
data.


Well, at least you understand that much.


But you don't, and go on to claim that it is:

Dingbat - interpolation is an assential part of going from the Bayer
array to the RAW data file. Please don't continue to pretend
otherwise.


You don't have a clue. Interpolation has *nothing* to
do with going from the Bayer array to the RAW data file.

It has to do with going from the raw data to an image
format, which as noted above is *no* *longer* *called* *raw*
*data*. It's usually either a TIFF or a JPEG data set.
That is *not* the data in a RAW data file.

Then stop talking about processing the RAW data to make an image.


I haven't been. If anything I've been talking about working backwards
from the RAW data file to reconstruct the original image.


Every time you mention "interpolation" or hint at the
de-mosaic process you are talking about processing the
RAW data to make an image. It is *never* a
reconstruction of the original image, because that
simply does not happen.

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)
  #18  
Old June 1st 09, 04:35 PM posted to rec.photo.digital,uk.rec.photo.misc
nospam
external usenet poster
 
Posts: 24,165
Default Could you actually see photos made from RAW files?

In article , Bob Larter
wrote:

He's talking about the *process* of converting from the RAW image to the
RGB image that you see on your screen, which includes Bayer
deconvolution. As he says, there is no 1:1 relationship between a pixel
("sensel") on the image sensor & a pixel on the RGB image that you see
on your screen.


there is a 1:1 mapping of senselsixels, although multiple sensels are
used to calculate one pixel. in other words, 10 million sensels on the
sensor- 10 million pixels in the image.
  #19  
Old June 1st 09, 06:16 PM posted to rec.photo.digital,uk.rec.photo.misc
nospam
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Posts: 24,165
Default Could you actually see photos made from RAW files?

In article , Bob Larter
wrote:

TTBOMK, the only transformation is the A2D
conversion. And that lack of transformations is, after all, the whole
point of the RAW file format in the first place.


basically that's true, however, nikon did apply white balance to the
raw data in some cameras before writing it to the file (d1 series, if i
recall). i doubt that's what he meant, and as far as i know, it's no
longer done.

not to sidetrack, but the only cameras that actually do a transform are
sigma/foveon. the raw data in a sigma raw file is *not* what came off
the sensor and has gone through quite a bit of processing before being
written to the file (which is kinda funny, given the crazy claims about
it being 'true colour').
  #20  
Old June 1st 09, 06:23 PM posted to rec.photo.digital,uk.rec.photo.misc
nospam
external usenet poster
 
Posts: 24,165
Default Could you actually see photos made from RAW files?

In article , Bob Larter
wrote:

He's talking about the *process* of converting from the RAW image to the
RGB image that you see on your screen, which includes Bayer
deconvolution. As he says, there is no 1:1 relationship between a pixel
("sensel") on the image sensor & a pixel on the RGB image that you see
on your screen.


there is a 1:1 mapping of senselsixels, although multiple sensels are
used to calculate one pixel. in other words, 10 million sensels on the
sensor- 10 million pixels in the image.


That's the default, but there's no mathematical necessity for the number
of output pixels to equal the number of output pixels.


i would hope the number of output pixels equals the number of output
pixels

unless you upscale or downscale, the number of input sensels will be
the same as the number of output pixels.
 




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