Copy vs Move

"Dave" wrote in message

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

I am fairly certain that copying a Jpeg does not do any damage to the data.

It is only the application of compression during a Save that does damage.

Roy G

Dave wrote:

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

It all depends on how you do it. If you open a JPEG in an application and copy it by using ‘Save as…’, the image will be compressed again and that causes data loss. If you move or copy the image by dragging it from one folder to another, there is no data loss.

—
Johan W. Elzenga johan<<at>>johanfoto.nl Editor / Photographer http://www.johanfoto.com

On Fri, 16 May 2008 15:51:56 +0100, "Roy G"
wrote:

"Dave" wrote in message

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

I am fairly certain that copying a Jpeg does not do any damage to the data.
It is only the application of compression during a Save that does damage.
Roy G

Roy, there is so many different views to this.
I have even seen a view years ago, somebody showing a jpg, proving that data lost only happen during the first or maybe the second, copy. Thereafter, it stays the same. I have seen other photos showing the way it keep on degrading. Being a ‘lossy’ format, the last seem to be more believable. You feel it is the compression doing it, and that make sense as well, because Tiff have no compression.

On Fri, 16 May 2008 17:15:20 +0200, (Johan W.
Elzenga) wrote:

Dave wrote:

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

It all depends on how you do it. If you open a JPEG in an application and copy it by using ‘Save as…’, the image will be compressed again and that causes data loss. If you move or copy the image by dragging it from one folder to another, there is no data loss.

Thanks Johan. Would this (also) mean, copying at ‘quality 12′ there will be no degrading? Or is ’12’ still an amount of compressing? I love what you are saying, because it is going to have me dragging images.

On Fri, 16 May 2008 17:39:18 +0200, Dave wrote:

On Fri, 16 May 2008 17:15:20 +0200, (Johan W.
Elzenga) wrote:

Dave wrote:

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

I am fairly certain that copying a Jpeg does not do any damage to the data.

It is only the application of compression during a Save that does damage.

Roy G

Roy, there is so many different views to this.
I have even seen a view years ago, somebody showing a jpg, proving that data lost only happen during the first or maybe the second, copy. Thereafter, it stays the same. I have seen other photos showing the way it keep on degrading. Being a ‘lossy’ format, the last seem to be more believable. You feel it is the compression doing it, and that make sense as well, because Tiff have no compression.

It all depends on how you do it. If you open a JPEG in an application and copy it by using ‘Save as…’, the image will be compressed again and that causes data loss. If you move or copy the image by dragging it from one folder to another, there is no data loss.

Thanks Johan. Would this (also) mean, copying at ‘quality 12′ there will be no degrading? Or is ’12’ still an amount of compressing? I love what you are saying, because it is going to have me dragging images.

Exactly the same message in different words. I accept this is the answer. How would I drag and drop a file after modifying it in PS?

Dave wrote:

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

COPYING – making an addiotnal copy
MOVING – moving the data from one place to other

The advantage of MOVING (if same drive) is SPEED and disk space.

On Fri, 16 May 2008 13:43:11 -0500, Joel wrote:

COPYING – making an addiotnal copy
MOVING – moving the data from one place to other

The advantage of MOVING (if same drive) is SPEED and disk space.

for in case you missed it, this is the question you should have answered:

How would I drag and drop (move) a file after modifying it in PS?

In article ,
Dave wrote:

Thanks Johan. Would this (also) mean, copying at ‘quality 12′ there will be no degrading? Or is ’12’ still an amount of compressing? I love what you are saying, because it is going to have me dragging images.

The highest quality setting in Photoshop is not lossless; there is still image degradation.

You can do anything you like with a JPEG as long as you do not open and resave it. For example, you can drag it from one hard disk to another, or from one folder to another. What you can not do without degradation is open it and then use Save As, at any quality level, to save it again.

—
Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html

In article ,
Dave wrote:

Exactly the same message in different words. I accept this is the answer. How would I drag and drop a file after modifying it in PS?

Click on the file icon, drag it wherever you like.

—
Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html

"Dave" wrote in message

On Fri, 16 May 2008 15:51:56 +0100, "Roy G"
wrote:

"Dave" wrote in message

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

I am fairly certain that copying a Jpeg does not do any damage to the data.

It is only the application of compression during a Save that does damage.
Roy G

Roy, there is so many different views to this.
I have even seen a view years ago, somebody showing a jpg, proving that data lost only happen during the first or maybe the second, copy. Thereafter, it stays the same. I have seen other photos showing the way it keep on degrading. Being a ‘lossy’ format, the last seem to be more believable. You feel it is the compression doing it, and that make sense as well, because Tiff have no compression.

Wrong!

Tiff files can be compressed, and it can be done losslessly.

Roy G

"Dave" wrote in message

On Fri, 16 May 2008 13:43:11 -0500, Joel wrote:

COPYING – making an addiotnal copy
MOVING – moving the data from one place to other

The advantage of MOVING (if same drive) is SPEED and disk space.

for in case you missed it, this is the question you should have answered:

How would I drag and drop (move) a file after modifying it in PS?

No !

The question you asked was about data corruption, and could it be caused by moving a file.

I think you have the answer that moving a file does not cause data loss, and neither does copying a file.

Why would anyone want to do editing on Jpegs, which are known to be a "lossy" format.

If you must use Jpeg, then reserve their use for your final version, and use a non-lossy format for the editing process.

Roy G

"Dave" wrote in message

With reference to the data lost when copying JPG’s,
is it the same when moving a file or not.
I assume it is the same because moving is nothing else
than copy and delete.

Copy will still keep a copy in your file. Move won’t.

On Fri, 16 May 2008 18:07:10 -0400, tacit wrote:

In article ,
Dave wrote:

Exactly the same message in different words. I accept this is the answer. How would I drag and drop a file after modifying it in PS?

Click on the file icon, drag it wherever you like.

Thanks tacit.
Right after pressing ‘send’ I thought this may be it:-)

On Fri, 16 May 2008 18:07:10 -0400, tacit wrote:

In article ,
Dave wrote:

Exactly the same message in different words. I accept this is the answer. How would I drag and drop a file after modifying it in PS?

Click on the file icon, drag it wherever you like.

Somewhere here is a misunderstanding.
I find no way, even with a combination of keys,
to drag a file from within PS and drop it onto a destination outside of it.

Example:
Unless I shoot RAW, my camera’s default format is jpeg.
Opening it in PS, curving it and sharpening it etc.
Now I have 2 or more layers.
Merge or flatten the layers.

Unlocking the background layer, selecting all, trying different key combinations, dragging the layer icon, nothing allow me to drag this *customized file from PS, as a JPG, to elsewhere.
And if I would succeed, it would be a PSD (I assume).

I thought I know Photoshop reasonably well,
but this proves to be tricky.
Maybe I am not as clever as I thought I am:-)

In article ,
Dave wrote:

Somewhere here is a misunderstanding.
I find no way, even with a combination of keys,
to drag a file from within PS and drop it onto a destination outside of it.

Ah. That’s correct; you can’t.

Example:
Unless I shoot RAW, my camera’s default format is jpeg.
Opening it in PS, curving it and sharpening it etc.
Now I have 2 or more layers.
Merge or flatten the layers.

Unlocking the background layer, selecting all, trying different key combinations, dragging the layer icon, nothing allow me to drag this *customized file from PS, as a JPG, to elsewhere.

Nope; you have to use Save As to save a .psd file, if your goal is to create a .psd. Doing this will not degrade the image. You degrade the image when you open a JPEG and then re-save it *as a JPEG*, because JPEG compression is lossy.

—
Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html

On Sat, 17 May 2008 10:48:32 -0400, tacit wrote:

In article ,
Dave wrote:

Somewhere here is a misunderstanding.
I find no way, even with a combination of keys,
to drag a file from within PS and drop it onto a destination outside of it.

Ah. That’s correct; you can’t.

Example:
Unless I shoot RAW, my camera’s default format is jpeg.
Opening it in PS, curving it and sharpening it etc.
Now I have 2 or more layers.
Merge or flatten the layers.

Unlocking the background layer, selecting all, trying different key combinations, dragging the layer icon, nothing allow me to drag this *customized file from PS, as a JPG, to elsewhere.

Nope; you have to use Save As to save a .psd file, if your goal is to create a .psd. Doing this will not degrade the image. You degrade the image when you open a JPEG and then re-save it *as a JPEG*, because JPEG compression is lossy.

Thanx tacit. This brings us back to what Roy, you yourself on other occasions, Johan and many more people said: Save as TIFF and convert to JPG only when necessary.

Anyway, the basis of this thread was my question whether there is data lost when dragging or moving a jpg file compared to copying it, and all of you’s agree there is no lost doing it. (Somehow it keep on being funny because moving, specially from a removable device or so, can be nothing else than copy & deletion of the original.)

But, from now on, I’ll be a drag(ger:-)

Dave

In article ,
Dave wrote:

Thanx tacit. This brings us back to what Roy, you yourself on other occasions, Johan and many more people said: Save as TIFF and convert to JPG only when necessary.

What that means is this:

Say you have a JPEG. You want to make changes to it. So you open in in Photoshop, and you edit it, and you save it as a JPEG again. Then tomorrow you say "Oh, I wasn’t finished working on it." So you open it and make more changes, then save it again as a JPEG. Then you’re like "Hmm, maybe I need to change the color a bit." So you open it, edit it some more, and save it as a JPEG.

The result will turn to mush, because you’ve re-saved it as a JPEG several times, losing quality each time.

Instead, open you file, edit it, and save it as a TIFF or a PSD. Then if you decide to change it again, you open the TIFF or PSD, edit it, and save it again. Only save as a JPEG when you are absolutely 100% sure you are done, and when you need to have a JPEG and absolutely no other file format will do. Keep the TIFF or PSD handy in case Fate proves you wrong about being done.

—
Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html

"tacit" wrote in message

In article ,
Dave wrote:

Thanx tacit. This brings us back to what Roy, you yourself on other occasions, Johan and many more people said: Save as TIFF and convert to JPG only when necessary.

What that means is this:

Say you have a JPEG. You want to make changes to it. So you open in in Photoshop, and you edit it, and you save it as a JPEG again. Then tomorrow you say "Oh, I wasn’t finished working on it." So you open it and make more changes, then save it again as a JPEG. Then you’re like "Hmm, maybe I need to change the color a bit." So you open it, edit it some more, and save it as a JPEG.

The result will turn to mush, because you’ve re-saved it as a JPEG several times, losing quality each time.

Instead, open you file, edit it, and save it as a TIFF or a PSD. Then if you decide to change it again, you open the TIFF or PSD, edit it, and save it again. Only save as a JPEG when you are absolutely 100% sure you are done, and when you need to have a JPEG and absolutely no other file format will do. Keep the TIFF or PSD handy in case Fate proves you wrong about being done.

Yes that is how I work a file too
shoot jpg> open in PS>work on it add layers etc, I always use the original as my bottom layer >save layered PSD in case of changes , and USE SAVE >PSD from dropdown
no need to use "save as"
(no change is made to original file)

then I save as tiff in flattened maybe cropped for customers who do not have PS to see PSD format
or for myself so I don’t have to open PS to see it>and smaller file size reads faster & this format is usable in most programs (flattened ones, not ones with alpha layers)
Then I use save for web>a version of tweaked file for sharing in email internet preview etc

Photography, kink, polyamory, shareware, and more: all at http://www.xeromag.com/franklin.html

In article <feKXj.35605$>,
"KatWoman" wrote:

Yes that is how I work a file too
shoot jpg> open in PS>work on it add layers etc, I always use the original as my bottom layer >save layered PSD in case of changes , and USE SAVE >PSD from dropdown
no need to use "save as"
(no change is made to original file)

That’s a good idea about keeping one file and simply saving!

—
dorayme