Deterioratig jpegs (Page 4): Yes, thank you for keeping on topic.

ediesaul

tradergeorge wrote:

If you practice sound methods and never modify your original, you should not have any "deterioration" of any file. Anything else is folly. There are many other differences between JPEG and RAW, but that is not what you asked...

Yes, thank you for keeping on topic.

revhen Loc: By the beautiful Hudson

I do my photos in JPEG. Here's what I do to keep from losing detail:

1. I save edited photo in a loss-less format. I use PNG, others TIFF, and yet there are others. This leaves me with the original and a loss-less copy.

2. When I do further post-processing I use the loss-less format and save in that format.

3. If I want to compress the photo for use online I save in JPEG and adjust the compression. Now I have 3 copies of the picture. Of course, I Save As with a different name for each.

From some 90 south of the Capital District on the Hudson

DirtFarmer Loc: Escaped from the NYC area, back to MA

ediesaul wrote:

...please change your self-image, put on a beret, and sport a mustache a la Dali!

Not having a beret, I'll stick with my baseball cap (worn forward so the visor does some good). I have a mustache already but it's more Groucho. Also a full beard, but not as artistic as Walt Whitman. My wife makes me trim it occasionally.

The full beard is compensatory hypertrophy (an excess growth that compensates for a lack elsewhere).

Telhunter Loc: New York City

I've uploaded extremely high quality jpegs to Facebook,with their recompression if someone saves the jpeg then re-uploads it back to Facebook it looks extremely degraded to me.

elee950021 Loc: New York, NY

The closest analogy to opening and saving the same jpeg image multiple times regardless of whether any pp has been done on it is making a copy machine print of an original document and then making a second copy of the first copy. Keep making new copies of each preceding copy and you'll eventually get one with broken splotchy type or tones if an image. This is a drastic example. Your jpeg image if saved many times loses sharpness and range of tones and develops artifacts and halos around contours. My workflow is to work on a raw, save as a Tiff to an "Edited" file, go back to the Tiff and and create your needed Jpegs or whatever you need.

emmons267 Loc: Arizona, Valley of the Sun

ediesaul,
I have worked with jpeg's for a long time and I've experienced exactly what you have. I'm able to edit and save jpeg's with little or no visible deterioration, even when they are resized to a larger format. Several responders have explained the process of correctly saving the jpeg's in order to minimize or virtually eliminate degradation, so I won't bother repeating that. Whatever you're doing, keep doing it. As they say, if it isn't broke, don't fix it.
Happy trails

ediesaul

DirtFarmer wrote:

Not having a beret, I'll stick with my baseball cap (worn forward so the visor does some good). I have a mustache already but it's more Groucho. Also a full beard, but not as artistic as Walt Whitman. My wife makes me trim it occasionally.

The full beard is compensatory hypertrophy (an excess growth that compensates for a lack elsewhere).

Thanks for your humor!

bigwolf40 Loc: Effort, Pa.

Ediesaul...As long as you make a copy of the original jpeg and do your pp on that copy you original will always be unchanged. What ever number you use to save the original you just use the same number with a dash like 10 is the original the pp copy would be 10-1 and so on for each copy you make and pp....Rich

ediesaul

elee950021 wrote:

The closest analogy to opening and saving the same... (show quote)

Thanks for your contribution. Sounds like your workflow is similar to many others concerned with degradation.

ediesaul

mfeveland wrote:

ediesaul,
I have worked with jpeg's for a long time and I've experienced exactly what you have. I'm able to edit and save jpeg's with little or no visible deterioration, even when they are resized to a larger format. Several responders have explained the process of correctly saving the jpeg's in order to minimize or virtually eliminate degradation, so I won't bother repeating that. Whatever you're doing, keep doing it. As they say, if it isn't broke, don't fix it.
Happy trails

Quite right. Thanks for the encouragement.

ediesaul

bigwolf40 wrote:

Ediesaul...As long as you make a copy of the original jpeg and do your pp on that copy you original will always be unchanged. What ever number you use to save the original you just use the same number with a dash like 10 is the original the pp copy would be 10-1 and so on for each copy you make and pp....Rich

I think Elements 12 tells me the number of the copy I've made. thanks for the idea. It might be useful for others.

RDH

oldtigger wrote:

Due to limited computer power i process all my images as jpeg.
Between my view of the first frame and my post of the finished stack to UHH the image may have been compressed/expanded 8 times.
The degradation is so bad you are lucky to see any detail.
Downsizing and resampling does so much damage that i usually just crop heavily and leave people to guess at what the original looked like.
I envy the power users with their RAW,TIFF, commercial programs and full resolution drop sites

Processing in jpg does not degrade the image, it is only when you save a file that you will loose image quality. Only save when work is complete and then save at the highest resolution possible. Never save to the original file name. There should be little loss. If you must shut the computer down before you finish save to the programs native file format, this is usually loss-less. In GIMP this is cxf in PS it would be png.

Actually, I do not think any of the major photo editing programs edit in jpg, I think they use their native format, then save in jpg.

bigwolf40 Loc: Effort, Pa.

ediesaul wrote:

I think Elements 12 tells me the number of the copy I've made. thanks for the idea. It might be useful for others.

I didn't think there was a difference between PS 12 and 11. The way I said is how I do it all the time no matter what PP program I use and have never had any trouble at all....Rich

ediesaul

bigwolf40 wrote:

I didn't think there was a difference between PS 12 and 11. The way I said is how I do it all the time no matter what PP program I use and have never had any trouble at all....Rich

Thanks for your comments.

rmalarz Loc: Tempe, Arizona

ediesaul wrote:

Hi! I often read that one of the major difference... (show quote)

The Huffman encoding, which is the basis of a jpg file, is a lossy data structure. Each time a jpg file is opened and saved, even without editing, it is changed.

Can you see the change, not immediately. However, if you open and save a file numerous times eventually you'll see artifacts or changes in the image start to appear.

Just for fun, I ran a "diff" program on two identical jpg files, one opened and closed, the other opened and saved. There was a significant number of bits that were changed in the process.
--Bob