jpeg Pictures (Page 2): There is no loss unless you edit the file.

gvarner Loc: Central Oregon Coast

There is no loss unless you edit the file.

GG50

Thank you for explaining this in understandable terms! Once again, you have made "stuff" clearer.

pbcbob Loc: Delray Beach, FL

Best solution IMHO is to immediately make a duplicate of the file, close it, and work off the duplicate.

jerryc41 Loc: Catskill Mts of NY

A few years ago, I opened, changed, and saved a JPEG image a hundred times. When I posted the first and last images here, they were virtually identical in quality.

I found them.

#1 (609kb), followed by #100 (594 kb). At the time (2010), some people said it wasn't a fair test because I didn't make enough changes - or something like that.

gvarner Loc: Central Oregon Coast

jerryc41 wrote:

A few years ago, I opened, changed, and saved a JPEG image a hundred times. When I posted the first and last images here, they were virtually identical in quality.

I found them.

#1 (609kb), followed by #100 (594 kb). At the time (2010), some people said it wasn't a fair test because I didn't make enough changes - or something like that.

I think that the issue is only important to purists and pixel peepers. Our photo club has a husband and wife duo who create beautiful images using nothing but JPEGs. So there’s that.

bsprague Loc: Lacey, WA, USA

jerryc41 wrote:

A few years ago, I opened, changed, and saved a JPEG image a hundred times. When I posted the first and last images here, they were virtually identical in quality.

I found them.

#1 (609kb), followed by #100 (594 kb). At the time (2010), some people said it wasn't a fair test because I didn't make enough changes - or something like that.

Well done Jerry! Maybe you should do it again with a small change on each save!

Fredrick Loc: Former NYC, now San Francisco Bay Area

charles tabb wrote:

I think this has been answered before but I can't remember.

If I open a jpeg file and then close it is there any loss?

If so, is the loss naggable?

After editing the loss is negligible. I’ve re-edited the same image multiple times and haven’t seen any loss in image quality.

If you’re a pixel peeper you probably would see a little. If I can’t see it with my eyes, I really don’t care, personally.

PHRubin Loc: Nashville TN USA

Ysarex wrote:

No loss.

Further loss to a JPEG results if the file is opened and edited and then re-saved as a JPEG.
Loss is caused primarily by editing (changes to tone/color) and secondarily by re-compression when re-saved.

Actually, if re-saved it may re-compress whether or not it was edited, depending on what opened and saved it.

Ysarex Loc: St. Louis

PHRubin wrote:

Actually, if re-saved it may re-compress whether or not it was edited, depending on what opened and saved it.

That's correct, BebuLamar noted the same early on page 1.

The thing is there's no reason to re-save it if you didn't make a change.

A single edit change to tone/color is liable to do more harm than 50 re-compressions of the file. Loss due to re-compression is not the reason to be concerned about editing JPEGs -- it's the editing that does damage.

DanCulleton

What editing software is being used?
With non-destructive editing, such as my beloved Lightroom, you are only “saving” the file when you export.
The terms opening, editing and saving do not apply.
Hence the answer is No.

Ysarex Loc: St. Louis

DanCulleton wrote:

What editing software is being used?
With non-destructive editing, such as my beloved Lightroom, you are only “saving” the file when you export.
The terms opening, editing and saving do not apply.

Lightroom will not overwrite the original and that's good. However when you export to a new file and you've made edit changes in LR then those edit changes will result in degradation of the image in the same way that editing changes will in say PS. LR won't save you from that. If you export from LR to a JPEG then you'll incur one round of re-compression.

DanCulleton wrote:

Hence the answer is No.

mindzye Loc: WV

pbcbob wrote:

Best solution IMHO is to immediately make a duplicate of the file, close it, and work off the duplicate.

Agreed, followed w/a question: Since jpg's are 8 bit, after processing is there an advantage to saving a copy in Tiff 16 bit, as opposed to Jpeg, particularly with intention of revisiting the p'processing ?
In researching saving options there seems to be differences of opinions from varied sources.

I most always, usually, often so, except for when I don't, start w/ raw images.

Opinion from the technically savvy?

Ysarex Loc: St. Louis

mindzye wrote:

Agreed, followed w/a question: Since jpg's are 8 bit, after processing is there an advantage to saving a copy in Tiff 16 bit, as opposed to Jpeg, particularly with intention of revisiting the p'processing ?

A very hedgy yes, but not much. It's going to depend on what you do in the way of editing. What you're basically doing is putting the 8 bit JPEG data into a 16 bit container. That process doesn't alter the 8 bit data one bit and so edits applied will basically have the same damaging effect as if you left the file 8 bit. You could conceivably benefit if your edit attempted to add gradient data into a sky for example.

mindzye wrote:

In researching saving options there seems to be differences of opinions from varied sources.

I most always, usually, often so, except for when I don't, start w/ raw images.

Opinion from the technically savvy?

frankraney Loc: Clovis, Ca.

charles tabb wrote:

Thanks for your answer.
I felt that what the sales person on B&H was wrong.
He just didn't explain it like you have.

B&H? I'm surprised the/he told you wrong.

CHG_CANON Loc: the Windy City

Some urban myths are surprisingly hard to stop. Just ask half of UHH about the dots they believe to exist inside pixel based images.