Will saving JPEGs as excellent quality (12) in CS3 reduce the amount of degradation?


Status
Not open for further replies.

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#1
Will saving JPEGs as excellent quality (12) in CS3 reduce the amount of degradation?

In my workflow I run automated batch processes with CS3 for noise reduction, effects, then later more editing if needed.

I always save the JPEGs in excellent quality (12) but does this cause the quality to degrade?

Thanx in advance for any help.
 

night86mare

Deregistered
Aug 25, 2006
25,541
0
0
www.pbase.com
#2
the more you open and save and close again, the more it will degrade

if you worry, just duplicate image, and save as separate file

you can see how it happens, just open a picture LARGE, save and close and open again a few hundred times :D

that said, saving at maximum quality (and file size) minimises that but it still happens
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#3
the more you open and save and close again, the more it will degrade

if you worry, just duplicate image, and save as separate file

you can see how it happens, just open a picture LARGE, save and close and open again a few hundred times :D

that said, saving at maximum quality (and file size) minimises that but it still happens
Do you mean saving in different file name? I guess it doesn't help because it JPEG discards the data it doesnt need once its saved, right? :think:

An image get saved up to 4 or 5 times during the workflow, you think its enough to cause significant damage?
 

night86mare

Deregistered
Aug 25, 2006
25,541
0
0
www.pbase.com
#4
maybe this will help

link

It is difficult to describe the JPG quality losses, except by seeing an example image (next page). JPG does not discard pixels. Instead it changes the color detail of some pixels in an abstract mathematical way. JPG is mathematically complex and requires considerable CPU processing power to decompress an image. JPG also allows several parameters, and programs don't all use the same JPG rules. Programs vary, some programs take shortcuts to load JPG faster but with less quality (browsers for example), and other programs load JPG slower with better quality. Final image quality can depend on the image details, on the degree of compression, on the method used by the compressing JPG program, and on the method used by the viewing JPG program.
the site will probably explain everything you want to know, take your time to read it, is a few pages.

if you have not done anything to the ORIGINAL jpg file and save whatever you edit as a NEW COPY

nothing will happen to your ORIGINAL, hope you get what it means

define significant.. i can't define significant for everyone. :) i think no problem for 8R prints, but if you want to print maximum size, perhaps. it depends on the amount of detail in your picture.
 

giantcanopy

Senior Member
Feb 11, 2007
6,232
2
0
SG
#5
The compression algorithm during the saving of a jpeg will lose a little information each time.
If you are worried, what I do usually is to process and edit in PSD ( create layers for each editing so they can be retrieved or reversed without data loss )

The final output for web then i save in jpeg

If you need to do amendment again, pull out the psd file ( or tiff for example ) and do amendments. Then save your new final file in jpeg for display purposes. I would not go back to the old jpeg file for editing. Having said that, like what night86mare mentioned, the changes might not be that visible especially when u save at high quality settings. but still ..

Ryan
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#6
maybe this will help

link



the site will probably explain everything you want to know, take your time to read it, is a few pages.

if you have not done anything to the ORIGINAL jpg file and save whatever you edit as a NEW COPY

nothing will happen to your ORIGINAL, hope you get what it means

define significant.. i can't define significant for everyone. :) i think no problem for 8R prints, but if you want to print maximum size, perhaps. it depends on the amount of detail in your picture.
Thanx for the link.

Ok got the meaning about the Original. No problem about losing the original jpeg coz I got the RAW.

Yeah, sometimes gotta print bigger than 8R and up to A3 or A2 sizes.

Thanx.
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#7
The compression algorithm during the saving of a jpeg will lose a little information each time.
If you are worried, what I do usually is to process and edit in PSD ( create layers for each editing so they can be retrieved or reversed without data loss )

The final output for web then i save in jpeg

If you need to do amendment again, pull out the psd file ( or tiff for example ) and do amendments. Then save your new final file in jpeg for display purposes. I would not go back to the old jpeg file for editing. Having said that, like what night86mare mentioned, the changes might not be that visible especially when u save at high quality settings. but still ..

Ryan
Ok its a solution thanx and I will think about it though it gets even more complicated to switch around file formats. I might still stick to jpg coz its events pictures so easily few hundred pics. The memory needed will be huge for PSD. I was enhancing a jpg picture my friend taken with her compact camera, the original jpeg was about 300kb. After my retouch work I save in PSD the file is 14mb. :think: So I can't image how huge it can get for pictures from 10MP DSLRs, times 500 pictures, :eek:
 

#8
Ok its a solution thanx and I will think about it though it gets even more complicated to switch around file formats. I might still stick to jpg coz its events pictures so easily few hundred pics. The memory needed will be huge for PSD. I was enhancing a jpg picture my friend taken with her compact camera, the original jpeg was about 300kb. After my retouch work I save in PSD the file is 14mb. :think: So I can't image how huge it can get for pictures from 10MP DSLRs, times 500 pictures, :eek:
You still have abit more to learn about file formats and how to use them. The fact that when you save a file in JPG will mean it gets compressed once the "saving" is done yes? What you need to know is, the moment you click to OPEN the JPG file, that file gets EXPANDED back to it's full size. For example, a colour A4 size photo is about 18mbs but when saved to JPG format at compression setting 10 for example gets you a jpg size about 1.5mb. But when you click to re-open that jpg file again...it will blow back up to about 18mb in your RAM. So what are you really saving? the only saving is your HDD when you save it to formats like PSD or TIFF which are UNCOMPRESSED formats. So if you are afraid working with those large files will slow down productivity as you edit it... you are actually not going to see any difference working with the PSD or TIFF or JPG.

Also, it is true the more often you save and resave the same JPG work file over and over again..it will degrade. But saving it at JPG compression setting of 12 is a waste of space too. The highest setting I know so far from any camera's highest JPG saving compression mode, it is only the equavalent of about 10 or 11 at most. In fact you only make the file bigger. Bigger does not mean it will still not mess with your quality over time.

Not hard to confirm this. Take a size reading of your JPG file of the photo shot. Then you open it up in Photoshop and then you just click save as and you see the JPG compression box come out yes? You select the various compression mode and see for yourself..each compression setting you select, there is an estimated size to show you what the end size would be. If you recall the original file size as it came out of your camera, you will find compression 12 actually ADD to the size. But that does not mean it adds more accuracy of colour and details hor heheheh... it just add more whatever is there. That means it can be good or bad stuff too.
 

Last edited:

David Kwok

Senior Member
Aug 23, 2008
1,107
0
36
Singapore
www.flickr.com
#9
Will saving JPEGs as excellent quality (12) in CS3 reduce the amount of degradation?

In my workflow I run automated batch processes with CS3 for noise reduction, effects, then later more editing if needed.

I always save the JPEGs in excellent quality (12) but does this cause the quality to degrade?

Thanx in advance for any help.
Choose a lossless compression offered by other file formats such as TIFF, PSD, or if you like, search your CD for the JPEG2000 plugin. JPEG2000 offers lossless compression too.

But seriously speaking, while it is true that even the highest JPEG compression gives you changes each time u save after alteration, the changes are normally quite insignificant.

I can assure you that the noise found in the images are more annoying than the highest quality JPEG artifacts introduced. Unless you are saving graphic design images which have hard and solid colours, you can hardly differentiate between noise and jpeg artifacts.

2 cents worth. Thanks
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#10
You still have abit more to learn about file formats and how to use them. The fact that when you save a file in JPG will mean ...
Thanx for taking the time to give a detailed reply. It was good info. In short I guess you mean saving in JPG will not result in faster file processing speed because it get uncompressed back to the original size when opened.

Thus its not much difference saving in PSD or TIFF except for the hard disk space it occupies.

Its a worthy consideration for the ability to retain layers.
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#11
Choose a lossless compression offered by other file formats such as TIFF, PSD, or if you like, search your CD for the JPEG2000 plugin. JPEG2000 offers lossless compression too.

But seriously speaking, while it is true that even the highest JPEG compression gives you changes each time u save after alteration, the changes are normally quite insignificant.

I can assure you that the noise found in the images are more annoying than the highest quality JPEG artifacts introduced. Unless you are saving graphic design images which have hard and solid colours, you can hardly differentiate between noise and jpeg artifacts.

2 cents worth. Thanks
More comfortable with PSD since its all photoshop functions are compatible and retained, but I heard TIFF is better for printing since its a standard format?
 

David Kwok

Senior Member
Aug 23, 2008
1,107
0
36
Singapore
www.flickr.com
#12
More comfortable with PSD since its all photoshop functions are compatible and retained, but I heard TIFF is better for printing since its a standard format?
Not exactly true. I have visited printing factories before, shops dedicated to printing such as ColorDoc found in Bras Brasah last time, and even the UltraSupplies photostating stall at Queensway. These shops cater to different user group, but still they cater for Adobe Photoshop fileformat. Adobe has been around in the industry for decades, if you tell me which stall is not using it, they are bound to phase out in a matter of time. Who will do business to make things difficult for the client and therefore difficult for their own biz ? Doesn't make sense at all. Adobe Photoshop has long being the de-facto standard for graphic design and printing. So unlikely it is a problem at all. But of course, TIFF makes the most portable file format, for it exist way longer than the existence of Adobe Photoshop. But sometimes u just need some tweaking that Adobe offers that I don't think you can save them without losing these features when converted into TIFF. I didn't exactly go and test out which is retained, but definitely all those color adjustment layers disappear, how about layer mask etc ???

If you are not concern or your printing job is basically just to print and you don't have all those bells and whistles that PSD offers, then go ahead with TIFF.

If you are deciding to print, use PSD and TIFF. If you are talking about delivering the product as just on screen for CD or other on screen media, just use JPEG at the highest quality. Choose one you prefer.

For an IT point of view, compression and decompression are much faster than reading and writing to file. Secondary storage are often the bottleneck to performance of a system. Next is the more you read and write from the disk, the more file cache you use and the less it is available for the rest of the system, of course, their algorithm to discard old information accordingly. But I can daringly tell u, under normal circumstances, your same memory sized image when using JPEG and other less compress-able file format, JPEG normally gives the best performance :)
 

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#13
Not exactly true. I have visited printing factories before...

Thanx, I will be saving my files that went through laying work as PSD. The rest will be JPG.

As mentioned, I am more comfortable with PSD.
 

#14
Thanx for taking the time to give a detailed reply. It was good info. In short I guess you mean saving in JPG will not result in faster file processing speed because it get uncompressed back to the original size when opened.

Thus its not much difference saving in PSD or TIFF except for the hard disk space it occupies.

Its a worthy consideration for the ability to retain layers.
Okay David covered the IT perspective so let me give you a graphic designer point of view: There are reasons between choosing PSD or TIFF for example. I am old school so that means if I have a file that has difference layers that is pile over to form on picture( example, a picture you have of a skyline, a aeroplane you strip into the sky portion of the skyline, some wordings in the top and and bottom) Yes if I still want to keep working on it then I will keep a PSD file.

I will choose TIFF if I am finished and I have achieve the end result of the graphic file. Now the only difference here is I will FLATTEN the graphic file before I save it to TIFF. A little bit of history about TIFF in recvent years. Now you can save a TIFF file ands till have multi-layers without flattening it. Back in the earlier days of Photoshop 6 ( if I am recalling correctly) you have to flatten the working layers before it allows you to save it as a TIFF.

So I still make the decision to always save a flatten image in TIFF in anycase, to save a multi layer file as a TIFF is possible now but it takes up more data so the save file is bigger. I hate to have a fatter file size then it needs to be but that is just me.

Now I save a tiff file always for the finished version and use that to give to suppliers to do my printing or magazine ads..etc. Why? Well a flatten version can NOT BE MANIPULATED. If you leave the layers as it is.... well.. if some itchy fingers or artist is not careful with his opening of my file and mistakenly shifted something around that I have not locked, you might have a print that has something out of place and you find that out later at the proofing stages or worst...when it have gone to PRINT!!!!. hehe..

Another reason I will always give a TIFF ( PSD is only optional upon their reguest or I trust or I label it as a raw data so they don't mistake it for a final artwork file to use) due to copyright use. If your picture has multiple images that is placed together to make one new picture for example, it is not hard to steal all those photo and use them separately for their own project or what ever. With a flattered one he can only steal that one scene or have to work hard to stripped out what he needs to use your photo without permission. If so, I want him to work hard to get it heheh..... So that is really about safe guarding your work in a way.

Something to think about.....
 

Last edited:

sjackal

Senior Member
Jul 9, 2008
4,490
10
38
#15
Okay David covered the IT perspective so let me give you a graphic designer point of view...
Yes Sammy, no way I am going to release layered files to clients. I know some photo artists are known for their unique look and colors and releasing layered files to clients is like releasing trade secrets and work flow.

I guess you do editorial work so your clients are professionals and appreciate or need TIFF. I guess if the clients are common consumers jpg are easier for them to understand.

Thanx again for your generous help. :)
 

Status
Not open for further replies.
Top Bottom