JPG Quality Degradation
Jul 25, 2014 18:26:08 #
I know they say each time you modify a JPG image it looses quality. My question is if you make the mods in LR and export a new file is there any loss? My guess is there is not.
Jul 25, 2014 18:28:32 #
Jul 25, 2014 18:55:46 #
Rongnongno, is 100 percent correct. I work mostly with JPEG, and will tell you, They are downgraded right out of the camera. To what degree is the question. I know there changed from 16 bit to 8 bit if that means anything. I will go onto say that in general you will not see the loss visually for at least like the first 10 saves of the same file. Take a JPEG, open it than save it. Photo1.1 then save it again as Photo1.2. Open it and save it as Photo1.3. Open it again and again. It will considerable closing to see any change. If you blow it up these changes will appear somewhat faster. I would recommend that if you are going to be working on a photo for any period of opening and closing that you SAVE as a DNG, TIF or whatever native format that chose that doesn't use compression. This will maintain the photo quality till the end. Or try to refrain from saving the original.
Jul 25, 2014 19:21:39 #
Bill Houghton wrote:
Rongnongno, is 100 percent correct. I work mostly... (show quote)
I was looking at some photographs I took 6/10 years ago, that came out of a point and shoot at around 6mp, now are less than a 1k-kbs {between 800kbs to 300kbs}, I am pissed.. I do not think there is any way to restore, some were pretty good, they could have been worked with, now they don't even look good on the computer screen, @ about 50% they are pixelated!! there crap!!
I know everyone has there own way of saving files! I have recently learned to take the photo JUST in RAW, work with that and save , now I only make a JPG if I am posting to web site, then delete it from my library,
I remind you, that is just the way I am doing it, and when I learn a better way I will go with that ..
good luck
Jul 25, 2014 19:34:25 #
redhogbill wrote:
I was looking at some photographs I took 6/10 years ago, that came out of a point and shoot at around 6mp, now are less than a 1k-kbs {between 800kbs to 300kbs},
Your quote has been shortened. Are you trying to tell use that your files shrank will sitting in the computer. I know they well shrink with repeated open and saving's but this is a new trend. Shrinking while in storage. Dang, when will this madness end.
Jul 25, 2014 20:44:01 #
Bill Houghton wrote:
Your quote has been shortened. Are you trying to tell use that your files shrank will sitting in the computer. I know they well shrink with repeated open and saving's but this is a new trend. Shrinking while in storage. Dang, when will this madness end.
I moved them a couple times! and I would say yes they did!! {shrink on there own} I have no other explanation for it, hoping someone could shed some light. i have the same computer from 1999 and loaded the photos in them!!!
not just A photo, but FILES of photos!!!!
maybe when I run a defrag and a compression?
{ I have to hand crank it every day to start it!!!!}
Jul 25, 2014 20:50:14 #
I think you might have Exported them, like in Picasa, Picasa and a few other programs will down size them for the web or emailing or uploading like to Face Book. I know if posted photo's on Goggle Web, then down loaded the on another computer and found them to be in the 1 meg or less range. But I have never heard of and file shrinking while on a hard drive. The only thing I know that shrinks well I won't go there. That is more of a chat room discussion.
It more or less makes into a thumbnail.
It more or less makes into a thumbnail.
Jul 25, 2014 20:57:26 #
Bill Houghton wrote:
I think you might have Exported them, like in Pica... (show quote)
no. these are pictures I took with an Olympus point and shoot, has some of the same settings as the big guns, "M/P/A/S/AUTO.. it was my entry level machine!! I did not even know what Photoshop was!! !much less Picasso!! in those days I thought you took a picture and that was it!!
and yes it is just a thumbnail! almost!!
talk about naïve!!!!!
but I figure I am up to the 1st grade now!!!{not sure I will graduate!!!!}!!!!!
Jul 25, 2014 21:02:10 #
[quote=Bill Houghton]I think you might have Exported them, like in Picasa, Picasa and a few other programs will down size them for t............
these were pics I took ,when I was learning, I was going to come back to them!! I am now at that point where I wanted to look at & process some old photos I took!!! but not now, it really sucked because I took them and thought I could re access them!!
these were pics I took ,when I was learning, I was going to come back to them!! I am now at that point where I wanted to look at & process some old photos I took!!! but not now, it really sucked because I took them and thought I could re access them!!
Jul 25, 2014 21:02:58 #
I just re-read your post, you mentioned a compression program. Are you talking about a old program that used to double your disk space, I think we called it a disk double. It would squashes the living daylights out of anything it could to make more room. Perhaps It was doing what it would say it would do. LOL. Sorry, but I have a very strong felling that it would zip those files, and after repeated times it zapped those files and a lot other date on your drive. Don't blame it on the JPEG.... I have JPEGS that are 15 years old or better and have no problems.
Just a note the first thing you lose threw repeated savings is the colorization. after about 30 saves you will have a nice black and white photo.
Just a note the first thing you lose threw repeated savings is the colorization. after about 30 saves you will have a nice black and white photo.
Jul 25, 2014 21:34:04 #
Racmanaz
Loc: Sunny Tucson!
Can't you just make a copy of the jpg file and work on that while saving the original jpg?
Jul 25, 2014 21:38:11 #
Racmanaz wrote:
Can't you just make a copy of the jpg file and work on that while saving the original jpg?
That's the safest way to work with a JPEG, we call it Save As. Then just close the original and nothing has changed since it hasn't gone threw the compression again. Only Saved As was compressed.
Jul 25, 2014 21:51:24 #
Racmanaz
Loc: Sunny Tucson!
Bill Houghton wrote:
That's the safest way to work with a JPEG, we call it Save As. Then just close the original and nothing has changed since it hasn't gone threw the compression again. Only Saved As was compressed.
So the jpg files that are degrading are the ones we edit without making the copy to edit?
Jul 25, 2014 22:00:31 #
What I'm saying, You open a JPEG. You make adjustments, If you save that file it will now be compressed and lose more of the information. Ever so slight, but you do lose it. To prevent that you Save with a different name. Sample: "file.jpg" after working on it you would Save As "File.1.jpg" then just close File.JPG. Nothing will happen to "File.jpg.
If you find you will be working on the file numerous times, then save it a TIF of PDF. DNG These files do not compress and will do no damage to the JPG original. or to it's self. Allowing you to open and save as often as you need.
The draw back is, the file size. a TIF file can well exceed 30 Megs in size where a JPEG is only 6 Meg.s
If you find you will be working on the file numerous times, then save it a TIF of PDF. DNG These files do not compress and will do no damage to the JPG original. or to it's self. Allowing you to open and save as often as you need.
The draw back is, the file size. a TIF file can well exceed 30 Megs in size where a JPEG is only 6 Meg.s
Jul 25, 2014 22:03:03 #
Computer guy here. You have to be careful uploading to Google or other online services that will make your pictures web friendly. I guard my originals with my life. And now that I am more serious about post-processing, I shoot in RAW+JPG most of the time, knowing I can go back to the RAW file and always be able to work with it non-destructively. I too have had the sad experience of ending up with the crippled web friendly version of a good picture and been unable to find the original higher quality one. Lesson learned the hard way.
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