I have just recently heard that if one saves a photo in jpeg and keeps on re editing and saving, that it loses quality each time. As I have quite a few editing programs, I do tend to keep on changing from one to the other if I am not happy with the result. Would it be better to save them in png and only export the final version in jpeg. I would be grateful if someone could please throw some light on this issue. Thanks in advance.
It's true you lose quality every time you change .jpg files. I tend to save as the file and keep the original to go back and use again, rather than keep on changing the same file. In answer to your question, .png is lossless - but it isn't necessarily the answer.
i do sometimes notice a degradation if i've been in lightroom, then photoshop, then back to lightroom - and sometimes this is quite marked, as with the battersea power station image i posted yesterday. once back in lightroom it was muddy and unsharp, unlike the crisp image i had been working on in photoshop. wondering if anyone understands this?! hopefully this is a related issue to your original question, diana - not wanting to divert your thread ;)
As a rule I always keep the original SOOC jpeg as it is. If I need to edit or play around with it in someway, I just make a duplicate of the original image, that way I always have the original to fall back on. It does take up a bit of storage space but it has come in useful a few times. Plus you can always see if your editing has made quite difference you hoped for.
I'm with @shannejw and @markp. I save the original SOOC jpeg separately, and try to use that for a starting point for different iterations of edits. I occasionally save projects in Photoshop's (Elements) *.psd format, which retains all of the steps, and I believe doesn't add any losses.
To your point of using more than one program? I don't know a good solution, I generally work withing Elements, using other programs (primarily Topaz filters) as plug-ins.
My biggest problem is that my general editing workflow is kind of like a Jazz solo. Improvised in the moment. undocumented, sometimes quite random, and pretty much impossible to precisely recreate.
@shannejw@annied@pistache@markp@lsquared Thanks everyone for your input which is very helpful. I am a bit like Larry @lsquared. I have my photos in LR, which means the original is always safe. I then export to Topaz Studio where I do most of my editing. Finally I go to Photoshop in case I need to change something or frame it. After all of that it goes out to 365. That means 3x exporting. I have realised that when I put a frame either inside or outside, the quality does suffer. (not that my photos are all great in the first place) So the question is still open ;-)
@ludwigsdiana Just to clarify, Diana: I do NOT use the stand alone version of Topaz studio, but use the modules as add-ins to PSE. They show up in the list of filters inside Elements. I have not noticed any degradation doing that that.
@ludwigsdiana I always shoot in RAW for me that's the negative and I make JPG's from it which I post to Flickr then share/down load from there to post.
Your camera's raw mode is going to be the best starting point. Keep working in raw until you are ready to publish. Only convert the image to JPG when you are finished.
What @tdaug80 said... and when I play I use a copy of the original. Sometimes I have several copied images made from the same raw file. takes time though if you have a few images on the camera.
I keep the SOOC for any photo that I think may be worth a revisit. I code it in LR as a 'red' color, so I know which the original was. Anything I am keeping long term or have posted, I code as purple for 'picked' (learned this from a PS tutor). I can also code using the stars or other colors, but I've found having the red color lets the originally easily pop and the purple shows me what was exported as jpg and posted somewhere, or what I thought worthy enough to export at some point. In keywords, you can also indicate Flickr, FB, 365project, etc to know where you have posted it, which comes in handy. I agree regarding taking the SOOC as a RAW file whenever possible, and exporting jpg versions of that RAW file.
In a similar vein to those above- I always have my "originals" on file in my computer. I then upload a copy into whatever program I'm using and save it separately. I haven't noticed any loss of clarity or sharpness when I'm using more than one program but then I am usually fiddling with some artistic effects and it's not as crucial.
@taffy@rjb71@sugarmuser@tdaug80@lsquared@ludwigsdiana@markp@shannejw@annied@pistache Hi folks, just thought I'd add my $.02 here. Like a few others, I use LR and always shoot RAW with all my cameras to the extent possible. Shooting in RAW gives you the ability to adjust your WB and other adjustments before any type of JPG compression is applied. In general stay away from JPG for as long as possible, all the way through the editing process up until posting on 365, Flickr, IG, etc. Use LR and do all your tonal type of adjustments including sensor noise reduction BEFORE going to Photoshop or Topaz or On1 or anything other application. LR is nondestructive, you can always go back to the SOOC raw image. If you want to vector off in two or more directions to try different edits you can easily create a duplicate copy within LR. Once you've completed ALL tonal adjustments (this includes top level crops/straighten, gradients, spot healing, brush adjustments, global tone curves, HSL adjustments, sensor sharpening (detailing), and lens or transform adjustments {not effects}), then take the image to PS or Topaz Studio. Once done with these filters, image sharpening, and any number of composition adjustments, review and re-adjust anything in LR. Lastly export to JPG (and last minute sizing desired) for posting. Along the way in LR when importing you should do key word tagging, color coding and apply any other ratings you want to use and apply. Again, just my $.02.
I think it matters more when you’re printing. If you download it into different editing programs they will effect the quality of the copy you are using. All depends on what programs you are playing around with, there are so many.
@mikegifford mike and others who clearly know their stuff :) thanks all so much for your help so far ... can i just ask ... once i'm done with my raw image in LR i click 'edit in PS with LR adjustments' ... image opens in PS ... do my edits ... save back to LR, where it appears as 'edit-tiff' ... only then do i export as a jpeg ... but often the 'edit-tiff' image back in LR is different from the PS image ... muddier, less sharp, sometimes even lighter or darker, or with slightly different colours. am i going mad?! if anyone could explain this i would be so grateful!
I would disagree with @chapjohn that it takes 100,000 savings of a jpg to show noticeable degradation. I have found that if you keep opening a jpg (and this is often because you move it around in different apps to apply different effects) and make changes then save again, after the first couple of times you will see it become less sharp and more grainy each time. I remember being mystified by this 20 years ago and then doing a PS course in the late 90's and finding out about lossy and lossless formats and being stunned to realise it wasn't my imagination after all :)
On top of this, some of the image manipulation apps will automatically apply a lot more compression when you save your image - the more compression, the more information (and therefore detail) you lose.
As far as how quickly JPG degrades with multiple saves, a key factor would be how high you set the compression. I always use minimum compression / highest quality. The more compression in the JPG algorithm, the quicker you'll see degradation.
Sounds like a good opportunity for some tests! Maybe if it is as rainy this weekend as they're saying...
@koalagardens Many post-processing programs today are lossless. Meaning they do not lose information when saving images. With high MP sensors giving you more information you will not notice any degradation of the jpg's.
For an image that is only going to be posted here or on FB or Instagram it probably doesn't matter. I only shoot RAW but if I have to transfer a file between editing programs I will use the TIFF or PSD format.
@chapjohn@koalagardens An editing program is not lossy or lossless. Only a file format is. An editing program can be "non destructive" meaning that it will not make changes to your original file as you edit but save information about the edits you perform in a so called "sidecar" file (a text file).
If you save an image in a lossy format (like jpg) it will lose detail information each time you save (it will try to compress the file size every time). How much quality you lose will be dependent on what quality you tell your editing program to use when saving. (If you choose the lowest quality the loss of detail will be visible immediately)
JPEG File Format Myths and Facts
by Sue Chastain
Updated October 24, 2018
With the explosion of scanners, digital cameras, and the World Wide Web, the JPEG image format has quickly become the most widely used digital image format. It's also the most misunderstood. Here are some common misconceptions and facts.
JPEG is the Proper Spelling: True
Although the files often end in the three-letter extension JPG or JP2 for JPEG 2000, the file format is spelled JPEG. It's an acronym for Joint Photographic Experts Group, the organization that developed the format.
JPEGs Lose Quality Every Time They're Opened and/or Saved: False
Simply opening or displaying a JPEG image doesn't harm it in any way. Saving an image repeatedly during the same editing session without ever closing the image will not accumulate a loss in quality. Copying and renaming a JPEG will not introduce any loss, but some image editors do recompress JPEGs when the "Save as" command is used. Duplicate and rename JPEGs in a file manager rather than using "Save as JPEG" in an editing program to avoid more loss.
JPEGs Lose Quality Every Time They're Opened, Edited and Saved: True
When a JPEG image is opened, edited and saved again it results in additional image degradation. It's very important to minimize the number of editing sessions between the initial and final version of a JPEG image. If you must perform editing functions in several sessions or in several different programs, you should use an image format that is not lossy, such as TIFF, BMP or PNG, for the intermediate editing sessions before saving the final version. Repeated saving within the same editing session won't introduce additional damage. It only happens when the image is closed, re-opened, edited and saved again.
JPEGs Lose Quality Every Time They're Used in a Page Layout Program: False
Using a JPEG image in a page layout program does not edit the source image so no quality is lost. However, you may find that your layout documents are considerably larger than the sum of the embedded JPEG files because each page layout software program uses different types of compression on their native document files,
If I Compress A JPEG At 70 Percent Then Later Reopen It And Compress It At 90 Percent, The Final Image Will Be Restored To A Quality Setting Of 90 Percent: False
The initial save at 70 percent introduces a permanent loss in quality that can't be restored. Saving again at 90 percent only introduces additional degradation to an image that has already had a considerable loss in quality. If you must decompress and recompress a JPEG image, using the same quality setting each time seems to introduce little or no degradation to the unedited areas of the image.
The same setting rule just explained doesn't apply when cropping a JPEG, however. Compression is applied in small blocks, typically 8 or 16-pixel increments. When you crop a JPEG, the entire image is shifted so that the blocks are not aligned in the same places. Some software offers a lossless cropping feature for JPEGs, such as the freeware JPEGCrops.
Choosing The Same Numeric Quality Setting For JPEGs Saved In One Program Will Give The Same Results As The Same Numeric Quality Setting In Another Program: False
Quality settings are not standard across graphics software programs. A quality setting of 75 in one program may result in a much poorer image than the same original image saved with a quality setting of 75 in another program. It's also important to know what your software is asking for when you set the quality. Some programs have a numeric scale with quality at the top of the scale so that a rating of 100 is the highest quality with little compression. Other programs base the scale on compression where a setting of 100 is the lowest quality and the highest compression. Some software and digital cameras use terminology like low, medium and high for quality settings. See screenshots of JPEG save options in various image editing software programs.
A Quality Setting Of 100 Does Not Degrade An Image At All: False
Saving an image to JPEG format always introduces some loss in quality, although the loss at a quality setting of 100 is barely detectable by the average naked eye. In addition, using a quality setting of 100 compared to a quality setting of 90 to 95 or so will result in a considerably higher file size relative to the degree of image loss. If your software doesn't provide a preview, try saving several copies of an image at 90, 95, and 100 quality and compare file size with image quality. Chances are there will be no distinguishable difference between the 90 and 100 image, but the difference in size could be significant. Keep in mind that subtle color shifting is one effect of JPEG compression – even at high-quality settings – so JPEG should be avoided in situations where precise color matching is important.
Progressive Jpegs Download Faster Than Ordinary Jpegs: False
Progressive JPEGs display gradually as they download so they'll initially appear at a very low quality and slowly become clearer until the image is fully downloaded. A progressive JPEG is larger in file size and requires more processing power to decode and display. Also, some software is incapable of displaying progressive JPEGs – most notably the free imaging program bundled with older versions of Windows.
Jpegs Require More Processing Power To Display: True
JPEGs must not only be downloaded but decoded as well. If you were to compare display time for a GIF and a JPEG with the same file size, the GIF would display marginally faster than the JPEG because its compression scheme does not require as much processing power to decode. This slight delay is barely noticeable except perhaps on extremely slow systems.
JPEG Is An All-Purpose Format Suitable For Just About Any Image: False
JPEG is best suited for large photographic images where file size is the most important consideration, such as images that will be posted on the Web or transmitted via email and FTP. JPEG is not suitable for most small images under a few hundred pixels in dimension, and it is not suitable for screenshots, images with text, images with sharp lines and large blocks of color, or images that will be edited repeatedly.
JPEG Is Ideal For Long-Term Image Archival: False
JPEG should only be used for archival when disk space is the primary consideration. Because JPEG images lose quality each time they're opened, edited and saved, it should be avoided for archival situations when the images require further processing. Always keep a lossless master copy of any image you expect to edit again in the future.
JPEG Images Don't Support Transparency: True
You may think you've seen JPEGs with transparency on the Web, but the image was in fact created with the intended background incorporated into the image in such a way that it appears seamless on a Web page with the same background. This works best when the background is a subtle texture where seams are indistinguishable. Because JPEGs are subject to some color shifting, however, the overlay may not appear totally seamless in some cases.
I Can Save Disk Space By Converting My GIF Images To Jpegs: False
GIF images have already been reduced to 256 colors or less. JPEG images are ideal for large photographic images with millions of colors. GIFs are ideal for images with sharp lines and large areas of a single color. Converting a typical GIF image to JPEG will result in color shifting, blurring, and loss in quality. The resulting file will often be larger. It's generally not of any benefit to convert GIF to JPEG if the original GIF image is more than 100 Kb. PNG is a better choice.
All JPEG Images Are High Resolution, Print-Quality Photos: False
Print quality is determined by the pixel dimensions of the image. An image must have at least 480 x 720 pixels for an average quality print of a 4" x 6" photo. It must have 960 x 1440 pixels or even more for a medium to high-quality print. JPEG is often used for images to be transmitted and displayed via the Web, so these images are typically reduced to screen resolution and do not contain enough pixel data to get a high-quality print. You may wish to use your camera's higher quality compression setting when saving JPEGs from your digital camera to reduce the damage caused by compression. I'm referring to the quality setting of your camera, not resolution which effects pixel dimensions. Not all digital cameras offer this option.
"As the typical use of JPEG is a lossy compression method, which reduces the image fidelity, it is inappropriate for exact reproduction of imaging data (such as some scientific and medical imaging applications and certain technical image processing work).
JPEG is also not well suited to files that will undergo multiple edits, as some image quality is lost each time the image is recompressed, particularly if the image is cropped or shifted, or if encoding parameters are changed – see digital generation loss for details. To prevent image information loss during sequential and repetitive editing, the first edit can be saved in a lossless format, subsequently edited in that format, then finally published as JPEG for distribution. "
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See https://www.digitaltrends.com/photography/jpeg-vs-png/
To your point of using more than one program? I don't know a good solution, I generally work withing Elements, using other programs (primarily Topaz filters) as plug-ins.
My biggest problem is that my general editing workflow is kind of like a Jazz solo. Improvised in the moment. undocumented, sometimes quite random, and pretty much impossible to precisely recreate.
@chapjohn Thanks, that is good to know, he never mentioned that ;-)
On top of this, some of the image manipulation apps will automatically apply a lot more compression when you save your image - the more compression, the more information (and therefore detail) you lose.
Sounds like a good opportunity for some tests! Maybe if it is as rainy this weekend as they're saying...
If you save an image in a lossy format (like jpg) it will lose detail information each time you save (it will try to compress the file size every time). How much quality you lose will be dependent on what quality you tell your editing program to use when saving. (If you choose the lowest quality the loss of detail will be visible immediately)
by Sue Chastain
Updated October 24, 2018
With the explosion of scanners, digital cameras, and the World Wide Web, the JPEG image format has quickly become the most widely used digital image format. It's also the most misunderstood. Here are some common misconceptions and facts.
JPEG is the Proper Spelling: True
Although the files often end in the three-letter extension JPG or JP2 for JPEG 2000, the file format is spelled JPEG. It's an acronym for Joint Photographic Experts Group, the organization that developed the format.
JPEGs Lose Quality Every Time They're Opened and/or Saved: False
Simply opening or displaying a JPEG image doesn't harm it in any way. Saving an image repeatedly during the same editing session without ever closing the image will not accumulate a loss in quality. Copying and renaming a JPEG will not introduce any loss, but some image editors do recompress JPEGs when the "Save as" command is used. Duplicate and rename JPEGs in a file manager rather than using "Save as JPEG" in an editing program to avoid more loss.
JPEGs Lose Quality Every Time They're Opened, Edited and Saved: True
When a JPEG image is opened, edited and saved again it results in additional image degradation. It's very important to minimize the number of editing sessions between the initial and final version of a JPEG image. If you must perform editing functions in several sessions or in several different programs, you should use an image format that is not lossy, such as TIFF, BMP or PNG, for the intermediate editing sessions before saving the final version. Repeated saving within the same editing session won't introduce additional damage. It only happens when the image is closed, re-opened, edited and saved again.
JPEGs Lose Quality Every Time They're Used in a Page Layout Program: False
Using a JPEG image in a page layout program does not edit the source image so no quality is lost. However, you may find that your layout documents are considerably larger than the sum of the embedded JPEG files because each page layout software program uses different types of compression on their native document files,
If I Compress A JPEG At 70 Percent Then Later Reopen It And Compress It At 90 Percent, The Final Image Will Be Restored To A Quality Setting Of 90 Percent: False
The initial save at 70 percent introduces a permanent loss in quality that can't be restored. Saving again at 90 percent only introduces additional degradation to an image that has already had a considerable loss in quality. If you must decompress and recompress a JPEG image, using the same quality setting each time seems to introduce little or no degradation to the unedited areas of the image.
The same setting rule just explained doesn't apply when cropping a JPEG, however. Compression is applied in small blocks, typically 8 or 16-pixel increments. When you crop a JPEG, the entire image is shifted so that the blocks are not aligned in the same places. Some software offers a lossless cropping feature for JPEGs, such as the freeware JPEGCrops.
Choosing The Same Numeric Quality Setting For JPEGs Saved In One Program Will Give The Same Results As The Same Numeric Quality Setting In Another Program: False
Quality settings are not standard across graphics software programs. A quality setting of 75 in one program may result in a much poorer image than the same original image saved with a quality setting of 75 in another program. It's also important to know what your software is asking for when you set the quality. Some programs have a numeric scale with quality at the top of the scale so that a rating of 100 is the highest quality with little compression. Other programs base the scale on compression where a setting of 100 is the lowest quality and the highest compression. Some software and digital cameras use terminology like low, medium and high for quality settings. See screenshots of JPEG save options in various image editing software programs.
A Quality Setting Of 100 Does Not Degrade An Image At All: False
Saving an image to JPEG format always introduces some loss in quality, although the loss at a quality setting of 100 is barely detectable by the average naked eye. In addition, using a quality setting of 100 compared to a quality setting of 90 to 95 or so will result in a considerably higher file size relative to the degree of image loss. If your software doesn't provide a preview, try saving several copies of an image at 90, 95, and 100 quality and compare file size with image quality. Chances are there will be no distinguishable difference between the 90 and 100 image, but the difference in size could be significant. Keep in mind that subtle color shifting is one effect of JPEG compression – even at high-quality settings – so JPEG should be avoided in situations where precise color matching is important.
Progressive Jpegs Download Faster Than Ordinary Jpegs: False
Progressive JPEGs display gradually as they download so they'll initially appear at a very low quality and slowly become clearer until the image is fully downloaded. A progressive JPEG is larger in file size and requires more processing power to decode and display. Also, some software is incapable of displaying progressive JPEGs – most notably the free imaging program bundled with older versions of Windows.
Jpegs Require More Processing Power To Display: True
JPEGs must not only be downloaded but decoded as well. If you were to compare display time for a GIF and a JPEG with the same file size, the GIF would display marginally faster than the JPEG because its compression scheme does not require as much processing power to decode. This slight delay is barely noticeable except perhaps on extremely slow systems.
JPEG Is An All-Purpose Format Suitable For Just About Any Image: False
JPEG is best suited for large photographic images where file size is the most important consideration, such as images that will be posted on the Web or transmitted via email and FTP. JPEG is not suitable for most small images under a few hundred pixels in dimension, and it is not suitable for screenshots, images with text, images with sharp lines and large blocks of color, or images that will be edited repeatedly.
JPEG Is Ideal For Long-Term Image Archival: False
JPEG should only be used for archival when disk space is the primary consideration. Because JPEG images lose quality each time they're opened, edited and saved, it should be avoided for archival situations when the images require further processing. Always keep a lossless master copy of any image you expect to edit again in the future.
JPEG Images Don't Support Transparency: True
You may think you've seen JPEGs with transparency on the Web, but the image was in fact created with the intended background incorporated into the image in such a way that it appears seamless on a Web page with the same background. This works best when the background is a subtle texture where seams are indistinguishable. Because JPEGs are subject to some color shifting, however, the overlay may not appear totally seamless in some cases.
I Can Save Disk Space By Converting My GIF Images To Jpegs: False
GIF images have already been reduced to 256 colors or less. JPEG images are ideal for large photographic images with millions of colors. GIFs are ideal for images with sharp lines and large areas of a single color. Converting a typical GIF image to JPEG will result in color shifting, blurring, and loss in quality. The resulting file will often be larger. It's generally not of any benefit to convert GIF to JPEG if the original GIF image is more than 100 Kb. PNG is a better choice.
All JPEG Images Are High Resolution, Print-Quality Photos: False
Print quality is determined by the pixel dimensions of the image. An image must have at least 480 x 720 pixels for an average quality print of a 4" x 6" photo. It must have 960 x 1440 pixels or even more for a medium to high-quality print. JPEG is often used for images to be transmitted and displayed via the Web, so these images are typically reduced to screen resolution and do not contain enough pixel data to get a high-quality print. You may wish to use your camera's higher quality compression setting when saving JPEGs from your digital camera to reduce the damage caused by compression. I'm referring to the quality setting of your camera, not resolution which effects pixel dimensions. Not all digital cameras offer this option.
The question was about re-editing images and transfering edits between editing programs. In those situations jpeg is not an ideal file format.
https://en.wikipedia.org/wiki/JPEG
"As the typical use of JPEG is a lossy compression method, which reduces the image fidelity, it is inappropriate for exact reproduction of imaging data (such as some scientific and medical imaging applications and certain technical image processing work).
JPEG is also not well suited to files that will undergo multiple edits, as some image quality is lost each time the image is recompressed, particularly if the image is cropped or shifted, or if encoding parameters are changed – see digital generation loss for details. To prevent image information loss during sequential and repetitive editing, the first edit can be saved in a lossless format, subsequently edited in that format, then finally published as JPEG for distribution. "