jpeg. degrade

Hi Ken

You are right, but the interpretation of Bob's words were as follows:

You load your original, you make changes and then save the original under another name. Meanwhile you continue to work on the same image without closing it. So you continue to work on the same image, making saves only so that you don't lose your work. Each time you save, you are only saving the changes from the same image.

This is the interpretation of Bob's post as given by someone else. The saving is done to prevent loss of the changes but you don't actually close the file.

The last save should be done in a loseless format.

Now truth to be told, this is NOT the way I work, merely an interpretation of someone elses's post.

However, as faar as I'm concerned you can just save in PS7 using #12 JPEG and so on ad-infinitum without degradation of the image.

Dave

KenEis said:

David Barkin said:

You are probably unaware of the fact that anyone named "David"
automatically stick together. So in this case I'm going to agree
with David.

First, in general, in PS 7 under JPEG save, if you save at #12,
then for all practical purposes, this is a lossless format.

Second, anything less then 12 will result in loss no matter that
you rename the file. However there is an easy way to prove or
disprove this. Simply resave, each time with a different name. Do
this 12 times. Then compare save one with save 12. You will see
loss!

Dave

Bob S said:

KenEis said:

David M. wrote:
Wrong Bob. You must save the file in some other lossless format
like TIF. Simply re-naming the file will still add further
compression if the file's format is kept in JPG format.

Click to expand...

Wrong David,
I don't know where people get this from...

As long as you save your original Jpg's and "save as" when editing
them your originals stay intact...

This has been dissussed many times before...

Bob

Click to expand...

Click to expand...

--
Ken Eis

Click to expand...

As I stated earlier, which some of you picked upon correctly, when you do a "save as" to an original Jpg and give it another name your original does not incur compression or degrade...

Yes, the file you just worked on and gave a new name may have some loss depending on how much compression you give it (if for the web you will want to compress it a bit and if it's for a print version the compression won't matter if you save as at a 12 or even 11)...but...

But...your original remains intact! This is like your negative...

It is senseless and a waste of storage space to convert all your photos to Tiff...

Just never overwrite your original, keep this as your negative and when you do edits just do as "save as" and give it a different name...

To be safe I keep all my originals in a folder marked as read only and put my edited versions in subfolders of the original...

Now does everyone see what I mean and agree?

I hope this clears this up for everbody...

Bob

Hi Bob

Ken already clarified your post, and I've already apologised and clarified your post but you have to admit that the following is confusing:

Mofongo said:

Wrong David,
I don't know where people get this from...

Click to expand...

Mofongo said:

As long as you save your original Jpg's and "save as" when editing them your > originals
stay intact...

Click to expand...

Mofongo said:

This has been dissussed many times before...

Click to expand...

Bob S said:

As I stated earlier, which some of you picked upon correctly, when
you do a "save as" to an original Jpg and give it another name your
original does not incur compression or degrade...

Yes, the file you just worked on and gave a new name may have some
loss depending on how much compression you give it (if for the web
you will want to compress it a bit and if it's for a print
version the compression won't matter if you save as at a 12 or even
11)...but...

But...your original remains intact! This is like your negative...

It is senseless and a waste of storage space to convert all your
photos to Tiff...

Just never overwrite your original, keep this as your negative and
when you do edits just do as "save as" and give it a different
name...

To be safe I keep all my originals in a folder marked as read only
and put my edited versions in subfolders of the original...

Now does everyone see what I mean and agree?

I hope this clears this up for everbody...

Bob

Click to expand...

Does'nt clear up a thing Bob. You're still wrong.

Perhaps you mean "Save As A Copy". Then yes, you will be duplicating the original with your added edits, unaffecting the original. But seeing as you neglect to specify "As A Copy", you are plainly and clearly wrong.

Also, when working with Layers, it's wisest to save in PSD format. It's also better to save in TIF for prints, since the color space won't be crunched down when going to print, making your profile a slight mismatch.
There are reasons behind saving in the different formats.
I hope that clears this up for you.
Now please do some Photoshop study and do us all a favor.
D.

Bob S said:

As I stated earlier, which some of you picked upon correctly, when
you do a "save as" to an original Jpg and give it another name your
original does not incur compression or degrade...

Yes, the file you just worked on and gave a new name may have some
loss depending on how much compression you give it (if for the web
you will want to compress it a bit and if it's for a print
version the compression won't matter if you save as at a 12 or even
11)...but...

But...your original remains intact! This is like your negative...

It is senseless and a waste of storage space to convert all your
photos to Tiff...

Just never overwrite your original, keep this as your negative and
when you do edits just do as "save as" and give it a different
name...

To be safe I keep all my originals in a folder marked as read only
and put my edited versions in subfolders of the original...

Now does everyone see what I mean and agree?

I hope this clears this up for everbody...

Bob

Click to expand...

It's confusing because he is'nt specifying As a Copy. He just thinks that re-naming a file and Save As will protect the original. Unless I'm reading him wrong or something.
But I don't think I am.

Re-naming the file and selecting Save As is a dangerous workflow as well. If you are not absolutely careful, you can permanently affect the image file. Another good reason to save an original as a TIF.
D.

David Barkin said:

Ken already clarified your post, and I've already apologised and
clarified your post but you have to admit that the following is
confusing:

David Barkin said:

Wrong David,
I don't know where people get this from...

Click to expand...

David Barkin said:

As long as you save your original Jpg's and "save as" when editing them your > originals
stay intact...

Click to expand...

David Barkin said:

This has been dissussed many times before...

Click to expand...

Bob S said:

As I stated earlier, which some of you picked upon correctly, when
you do a "save as" to an original Jpg and give it another name your
original does not incur compression or degrade...

Yes, the file you just worked on and gave a new name may have some
loss depending on how much compression you give it (if for the web
you will want to compress it a bit and if it's for a print
version the compression won't matter if you save as at a 12 or even
11)...but...

But...your original remains intact! This is like your negative...

It is senseless and a waste of storage space to convert all your
photos to Tiff...

Just never overwrite your original, keep this as your negative and
when you do edits just do as "save as" and give it a different
name...

To be safe I keep all my originals in a folder marked as read only
and put my edited versions in subfolders of the original...

Now does everyone see what I mean and agree?

I hope this clears this up for everbody...

Bob

Click to expand...

Click to expand...

Never change ANYTHING about your original!!! By saving it as a TIFF you are almost surely throwing away your EXIF metadata and using much more storage space. You gain exactly nothing. And if you don't toss all your EXIF metadata, likely you will modify it and lose at least some of it. Every camera seems to have its own variation, and how it is stored: a conversion is unlikely to leave it all alone.

David M. said:

It's confusing because he is'nt specifying As a Copy. He just
thinks that re-naming a file and Save As will protect the original.

Click to expand...

A bit confusing perhaps, and a bit unsafe, but at least the basic idea is right - don't touch your originals.

David M. said:

Unless I'm reading him wrong or something.
But I don't think I am.
Re-naming the file and selecting Save As is a dangerous workflow as
well. If you are not absolutely careful, you can permanently
affect the image file. Another good reason to save an original as
a TIF.

Click to expand...

WRONG! WRONG!!!!! Don't mess with your negatives!

Always save the original exactly as it comes from the camera. Saving it as a TIFF will lose the EXIF metadata. It shoud be saved in exactly the same format as it comes from the camera.

David M. said:

It's confusing because he is'nt specifying As a Copy. He just
thinks that re-naming a file and Save As will protect the original.
Unless I'm reading him wrong or something.

Click to expand...

Confusing yes, and dangerous - but the right basic idea: don't mess with your negatives.

David M. said:

But I don't think I am.
Re-naming the file and selecting Save As is a dangerous workflow as
well. If you are not absolutely careful, you can permanently
affect the image file. Another good reason to save an original as
a TIF.

Click to expand...

Wrong. There will be no improvement of the original image by saving it as a TIFF.

This whole discussion is running along on the basis of misunderstanding. I am making the point about saving the originals exactly as they come from the camera because I got suckered into converting them to TIFFs with my first digicam. By the time I figured out that was a bad idea, I had lost the EXIF metadata in a bunch of them. I have also seen that many cameras have odd ways of keeping their metadata which does not entirely survive any transformation. Not trying to start a flame war, just trying to keep some confused newbie from making the same mistake I made.

David M. said:

Does'nt clear up a thing Bob. You're still wrong.
Perhaps you mean "Save As A Copy". Then yes, you will be
duplicating the original with your added edits, unaffecting the
original. But seeing as you neglect to specify "As A Copy", you
are plainly and clearly wrong.

Click to expand...

There is nothing wrong with "Save as" and then selecting a different name and/or file format. It keeps the original file from being overwritten. And that is what Bob is trying to explain here.

Besides, what's wrong with the original JPEG from your camera? You won't increase the detail by saving as TIFF (or any other format).

David M. said:

Also, when working with Layers, it's wisest to save in PSD format.

Click to expand...

It's probably the only way to keep the layering editable afterwards anyway.

David M. said:

It's also better to save in TIF for prints, since the color space
won't be crunched down when going to print, making your profile a
slight mismatch.

Click to expand...

You're right in theory. However, one known downside of TIFF in printing is that they adopt a bluish cast. Having said that, it's quite possible that a home printer isn't affected by it (as opposed to a press).

If you really want to store your files in a lossless format, why not use EPS? That will keep your colors intact, save your paths, ... Can your TIFF do that?

My apologies Bill. I was misunderstanding you. As it was stated previously here, it's easy to do in this topic.
You are correct.
D.

Bill Drew said:

David M. said:

It's confusing because he is'nt specifying As a Copy. He just
thinks that re-naming a file and Save As will protect the original.

Click to expand...

A bit confusing perhaps, and a bit unsafe, but at least the basic
idea is right - don't touch your originals.

Member said:

Unless I'm reading him wrong or something.
But I don't think I am.
Re-naming the file and selecting Save As is a dangerous workflow as
well. If you are not absolutely careful, you can permanently
affect the image file. Another good reason to save an original as
a TIF.

Click to expand...

WRONG! WRONG!!!!! Don't mess with your negatives!

Click to expand...

Pieter Gordebeke said:

Pieter Gordebeke wrote:

There is nothing wrong with "Save as" and then selecting a
different name and/or file format. It keeps the original file from
being overwritten. And that is what Bob is trying to explain here.

Click to expand...

Peter,

I'm so glad you also understand the basic principle I've been trying to explain here...

Seems a lot of myths get told over and over and believed around here...

Again, "save as" to a different name and your original is safe...

Bob

David M. said:

David M. wrote:
Does'nt clear up a thing Bob. You're still wrong.

Click to expand...

Sorry David but you are still wrong...other people seem to understand the basic principle here, I don't see where you're stuck...

David M. said:

Perhaps you mean "Save As A Copy". Then yes, you will be
duplicating the original with your added edits, unaffecting the
original. But seeing as you neglect to specify "As A Copy", you
are plainly and clearly wrong.

Click to expand...

Save as a copy is just another way to accomplish this...(maybe a safer one)...

David M. said:

Also, when working with Layers, it's wisest to save in PSD format.
It's also better to save in TIF for prints, since the color space
won't be crunched down when going to print, making your profile a
slight mismatch.

Click to expand...

I'll save in PSD format sometimes if an involved edit is being done and I may want to go back...

David M. said:

There are reasons behind saving in the different formats.

Click to expand...

if you are doing an complicated edit and may go back to it for a change...

David M. said:

I hope that clears this up for you.

Click to expand...

I'm clear as a a bell on this...

David M. said:

Now please do some Photoshop study and do us all a favor.

Click to expand...

LOL...I think we know who needs to study some more...

My originals are burnt to CD as a Jpg....when I do an edit on them and "save as" to a different name, how is compression going to be applied to the original on a write once CD? Think about it...

Have fun with all those huge Tiffs, you're no better off for it...

Bob

Bob, while I still stand behind my previously stated reason behind color space integrity using lossless formats, and using As A Copy, I refer you to my post of about 4 hours ago apologizing to you for my misunderstandings.
Thanks,
D.

Bob S said:

Mofongo said:

David M. wrote:
Does'nt clear up a thing Bob. You're still wrong.

Click to expand...

Sorry David but you are still wrong...other people seem to
understand the basic principle here, I don't see where you're
stuck...

Mofongo said:

Perhaps you mean "Save As A Copy". Then yes, you will be
duplicating the original with your added edits, unaffecting the
original. But seeing as you neglect to specify "As A Copy", you
are plainly and clearly wrong.

Click to expand...

Save as a copy is just another way to accomplish this...(maybe a
safer one)...

Mofongo said:

Also, when working with Layers, it's wisest to save in PSD format.
It's also better to save in TIF for prints, since the color space
won't be crunched down when going to print, making your profile a
slight mismatch.

Click to expand...

I'll save in PSD format sometimes if an involved edit is being done
and I may want to go back...

Mofongo said:

There are reasons behind saving in the different formats.

Click to expand...

if you are doing an complicated edit and may go back to it for a
change...

Mofongo said:

I hope that clears this up for you.

Click to expand...

I'm clear as a a bell on this...

Mofongo said:

Now please do some Photoshop study and do us all a favor.

Click to expand...

LOL...I think we know who needs to study some more...

My originals are burnt to CD as a Jpg....when I do an edit on them
and "save as" to a different name, how is compression going to be
applied to the original on a write once CD? Think about it...

Have fun with all those huge Tiffs, you're no better off for it...

Bob

Click to expand...

Sorry if I sounded like a flaming rant, but I got tangled in this kind of missunderstanding of how to save the original photos and lost a bunch of stuff as a newbie. I suspect that you weren't really telling folks to convert their originals, but it did sound that way.

If I had a nickel every time I tripped over my keyboard and said something silly, I'd have a couple of D1Xs instead of my Casio

David M. said:

My apologies Bill. I was misunderstanding you. As it was stated
previously here, it's easy to do in this topic.
You are correct.
D.

Click to expand...

David M. said:

Bob S said:

David M. said:

David M. wrote:
Does'nt clear up a thing Bob. You're still wrong.

Click to expand...

Sorry David but you are still wrong...other people seem to
understand the basic principle here, I don't see where you're
stuck...

David M. said:

Perhaps you mean "Save As A Copy". Then yes, you will be
duplicating the original with your added edits, unaffecting the
original. But seeing as you neglect to specify "As A Copy", you
are plainly and clearly wrong.

Click to expand...

Save as a copy is just another way to accomplish this...(maybe a
safer one)...

David M. said:

Also, when working with Layers, it's wisest to save in PSD format.
It's also better to save in TIF for prints, since the color space
won't be crunched down when going to print, making your profile a
slight mismatch.

Click to expand...

I'll save in PSD format sometimes if an involved edit is being done
and I may want to go back...

David M. said:

There are reasons behind saving in the different formats.

Click to expand...

if you are doing an complicated edit and may go back to it for a
change...

David M. said:

I hope that clears this up for you.

Click to expand...

I'm clear as a a bell on this...

David M. said:

Now please do some Photoshop study and do us all a favor.

Click to expand...

LOL...I think we know who needs to study some more...

My originals are burnt to CD as a Jpg....when I do an edit on them
and "save as" to a different name, how is compression going to be
applied to the original on a write once CD? Think about it...

Have fun with all those huge Tiffs, you're no better off for it...

Bob

Click to expand...

Click to expand...

I haven't been participating in this thread, but I have been following it, since I'm going through all this right now with my own work. So if I get this right, if I burn a copy of the originals straight out of the camera I'm fine, I won't lose a thing. Then whenever I want to work on a pic I can just create a duplicate in Photoshop, do whatever I wish with it, and never have to worry about that original. See that's why I'm curious why all this dithering about the original, since if you have it on a cd then, unless I miss something here, you never have to worry about it again, or at least until the cd wears out or breaks. I gotta say thanks, this has been a very informative thread.
God Bless,
Jim
http://www.pbase.com/jrj02

Exactly right.

Further, once you have the originals in a safe, read-only place, the choices format is not very important in most cases. If you ever construct an image with 186 layers, you will really want to save that in your editor's native format. If you are going to send an image to someone who jumps up and down about the virtues of TIFFs, it will save everyone's nerves if you send the image as a TIFF. Otherwise (unless you are going to do further editing on an image), a low compression JPEG is just fine IMHO.

Jim said:

I haven't been participating in this thread, but I have been
following it, since I'm going through all this right now with my
own work. So if I get this right, if I burn a copy of the originals
straight out of the camera I'm fine, I won't lose a thing. Then
whenever I want to work on a pic I can just create a duplicate in
Photoshop, do whatever I wish with it, and never have to worry
about that original. See that's why I'm curious why all this
dithering about the original, since if you have it on a cd then,
unless I miss something here, you never have to worry about it
again, or at least until the cd wears out or breaks. I gotta say
thanks, this has been a very informative thread.
God Bless,
Jim
http://www.pbase.com/jrj02

Click to expand...

David M. said:

David M. wrote:
Bob, while I still stand behind my previously stated reason behind
color space integrity using lossless formats, and using As A Copy,
I refer you to my post of about 4 hours ago apologizing to you for
my misunderstandings.
Thanks,

Click to expand...

No problem David,

I see where you apologized to Bill and we seem to agree now on the integrety of the original after doing a "save as"...

You are corect that's it's best to work off a copy of the original cause I have accidently hit "save" instead of "save as" when working off an original...Doh!

Anyways, this has been an interesting thread and I'm sorry we butted heads for a bit...

Happy shooting!

Bob

Ok, I finally got it.

Immediately save the file as an 80;1 JPEG and delete the original. Keep saving your work as you go along by giving your JPEG a new name and reloading the new file. Comtinue saving at 80 to 1 until there is no dicernable image whatsoever.

Then take your camera, put on a nine pound lens and beat it over your head until either:

a. You pass out or
b. The camera is smashed.
c. Dump the damn computer too!

Then quickly without losing time (assuming your not in the hospital) take up a new hobby or profession like weaving or candle making - Something without stresse!

Dave

I'll throw a bit of gasoline on the fire

I think we all agree that saving (not copying!) a JPEG does degrade the image. The question is, "how much does it degrade it?" IMHO, if an image is saved as a low compression (high file size) JPEG, that is good enough unless I am going to keep working on it. I'd go further and say that if you cannot tell the difference between a one notch change in your curve, level, hue, saturation, sharpening, .... adjustment values - there is almost certainly more error in those adjustments than the error due to the JPEG compression. And how many of us have our monitors and printers calibrated so they match exactly?

There has to be a few people (David M. sounds like one) who can tell that small a difference in every one of their adjustments, but I cannnot, and I'm sure not many other people can either. So for just about everyone, JPEG is a fine format to save your final image. All the other errors we have overwhelm the problem with JPEG compression.

And you did keep your unaltered originals so you can redo your adjustments when you know how to do them better, didn't you?

Since I haven't seen it suggested in this thread, I suggest an experiment. Open an image and save it as a TIFF. Then save it as a JPEG, load the JPEG, save it again, load again, save again, ...., load it again. Then load the TIFF, put in a layer on top of the many saved/loaded JPEG, and choose difference as the blending mode.

Now put your camera on contious shooting to get two pictures. Fire it with the self-timer so there is no motion. Compare the difference between those so you should be looking at pure noise.

If the noise level generated by your camera is more than the difference between a TIFF and a many saved/loaded JPEG, I'd say you shouldn't worry about problems due to JPEG compression. Ever. (Or at least until you get a better camera.

It is well worth doing at least the first part of the experiment. That will show where the major JPEG compression problems are - high contrast edges. That should start some thoughts about sharpening, a subject I hope to gain a little understand of in the next couple of decades.

OK. Being the "newbie" that at least some of you are trying to protect from dangerous errors (which I have already made), please advise on the following plan:

1. Burn a CD-R of all orginals (protect the digital "negative" as it were)

2. Work on photo in PSE2.0 and save as Photoshop (PSD I think) file (big though 15-20MB).

Now the questions (please bear in mind that I am working in PSE2.0 not PS) so I have limited capabilities:

1. I want to e-mail an edited PSD photo to a friend but its 18MB. What do I do? Can I WinZip the large file (or group of files) in XP and send it? Any consequences?

2. I burn my friend a CD-R with the edited and resaved photos (PSD). Can he view them or does he need to have Photoshop? Can I convert them back to JPEGs or another format he can use? If so, how? Any loss?

3. TIFF, PSD, whats the difference/advantage with respect to each other?

That ought to do it for now. Looking forward to your collective advice.

--
Ron
----------------------------------------------------
Coolpix 4500/Photoshop Elements 2.0

Hi Ronbo,

Sending such a huge file (even zipped) will be practically impossible through email. For just viewing the JPG "on the other side", you can create a JPG copy with a moderate compression setting and email that one.

If you want to do this with multiple files, let me recommend you the application I wrote, ABC-View Manager. It will create temporary copies of your originals, at a lower resolution and moderate compression settings, thus resulting in file sizes 50K (depending on dimensions). It is fully automatic - just select the pictures, press the "email-a-friend" button and select the resolution. It integrates with Outlook or Outlook Express (in fact with any other Mapi mail client).

Here's an introductory article (step 7 deals with emailing):
http://www.abc-view.com/articles/article4.html

Hope this helps,

Nils Haeck

Ronbo said:

1. I want to e-mail an edited PSD photo to a friend but its 18MB.
What do I do? Can I WinZip the large file (or group of files) in
XP and send it? Any consequences?
That ought to do it for now. Looking forward to your collective
advice.

--
Ron
----------------------------------------------------
Coolpix 4500/Photoshop Elements 2.0

Click to expand...

--
Nils Haeck
Developer of ABC-View Manager (image management software)
http://www.abc-view.com