Any advantage to saving as TIFF

[raven-au]

Hi all,

Is there any advantage in saving to the TIFF format after filtering
from an original JPEG prior to editing, instead of saving to a JPEG
again?

Ian

[Spire]

There is an advantage in terms of image quality, since JPEG is lossy while TIFF is lossless.

How much of an advantage? It depends on the Quality setting that you have selected at the time that you save the filtered JPEG file.

At the same time, there is a disadvantage in terms of file size. For photographic images, a TIFF file will almost always be considerably larger than a JPEG file.

[raven-au]

How much of an advantage? It depends on the Quality setting that you have selected at the time that you save the filtered JPEG file.

At the same time, there is a disadvantage in terms of file size. For photographic images, a TIFF file will almost always be considerably larger than a JPEG file.

Yes, but I guess my real question then is "if I save at 99% quality will the
difference be of any consequence at all"?

Or would there be any difference if the JPEG was saved at 100%?
I haven't checked the JPEG size at 100% yet.

The size difference for my JPEG at 99% is about 6 times smaller than
the TIFF but that's not really the question. It's more a question about
what it costs me in terms of quality since I generally need to clean up
the photos anyway.

Ian

[Spire]

There will always be a difference, even with the Quality set to 100% for the JPEG output; that's just the way lossy compression works. Whether the difference is small enough to justify the savings in file size is something only you can decide.

So how do you decide? Well, here's a handy trick that might help you visualize the difference:

1. Filter an image, and save the output twice: once as a TIFF file (lossless), and again as a JPEG file (lossy; the Quality setting is up to you).
2. Load both filtered files into Photoshop.
3. Select the entire Background layer of the opened JPEG file, then copy and paste it to a new layer in the opened TIFF file.
4. Set the new layer's Blend Mode to Difference.

If you follow this procedure, you should see a completely black image, except for the parts where there are differences introduced by the JPEG compression. If you saved the JPEG file with a very low Quality setting in the first step, the difference should be pretty dramatic. If the entire image looks completely black to you, the difference is probably small enough to justify saving the image in JPEG format instead of TIFF.

It's more a question about what it costs me in terms of quality since I generally need to clean up the photos anyway.

If you're going to be any further editing on the filtered output of Neat Image, you should definitely save it in TIFF. JPEG, being lossy, is not designed to be used as an intermediary format. Save as TIFF while you're still editing, and then save the final output as JPEG if desired.

[raven-au]

If you follow this procedure, you should see a completely black image, except for the parts where there are differences introduced by the JPEG compression. If you saved the JPEG file with a very low Quality setting in the first step, the difference should be pretty dramatic. If the entire image looks completely black to you, the difference is probably small enough to justify saving the image in JPEG format instead of TIFF.

Yep, that's what I thought.

It's more a question about what it costs me in terms of quality since I generally need to clean up the photos anyway.

If you're going to be any further editing on the filtered output of Neat Image, you should definitely save it in TIFF. JPEG, being lossy, is not designed to be used as an intermediary format. Save as TIFF while you're still editing, and then save the final output as JPEG if desired.

Again, my thoughts.

I'm a bit new to the photo stuff so thanks for the difference blend mode check procedure.
I can't afford Phtotshop here at home but Elements should be able to do this just fine.

Ian