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I have a lot of family pictures saved in Google Drive as JPEGs - not JPEG 2000 - as they were initially acquired.

I thought the problem with JPEGs was artifact at sharp edges, which is not too much of an issue with landscape and family pictures, but I recently have become concerned about the fact that I read there is progressive loss every time they are opened.

Should I save each one of them as a PNG (or TIFF)? Space is not an issue.

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There is no data loss from simply opening them, only by changing them & re-saving.

Any data already lost can never be recovered.
Simply converting now to a lossless format will not change the images from what they currently show.

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  • Does changing them includes something as innocuous as playing with brightness and contrast? Because if this is the case, then one may assume changing now to PNG or TIFF would be the proverbial 'better late than never'... – Antoni Parellada Apr 17 at 16:11
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    If you make any change which requires you to save, then yes. If the initial saved quality was 90% or higher, you will probably never notice. If you are going to go to lossless, then use PNG. TIF is rather specialist & will make huge file sizes [like 150MB rather than 6MB]. – Tetsujin Apr 17 at 16:14
  • I guess the rule of thumb is then, "Save as PNG if you find yourself editing a picture, and take new pics in PNG format? – Antoni Parellada Apr 17 at 16:34
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    That would feel fair, yes, if your gear is capable of initially saving in png. – Tetsujin Apr 17 at 16:40
  • Any thoughts on using Google Drive as storage? – Antoni Parellada Apr 17 at 17:55
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I recently have become concerned about the fact that I read there is progressive loss every time they are opened.

Opening an image without editing and resaving does not alter it. However, xenoid points out [1, 2] that this misconception may have been perpetuated by the behavior of some versions of Windows Picture Viewer in Windows XP, where some edits, such as rotation, were silently saved to disk without notifying the user.

Should I save each one of them as a PNG (or TIFF)?

If concern about quality loss from viewing them is the sole reason for conversion, you should leave them alone. Other reasons you may have to convert should be evaluated independently.

I have a lot of family pictures saved in Google Drive as JPEGs - not JPEG 2000 - as they were initially acquired.

Most people who regularly work with images would have recommended saving a copy of the original in whatever format they happen to be in.

See also:

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  • Opening an image without editing and resaving does not alter it This is/was not always true. The Windows image viewer in WinXP used to silently re-save the picture if you rotated it in the viewer (in addition to mishandling the EXIF rotation flag). – xenoid Apr 17 at 21:14
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    Of course, for you and me. But for most people it is just looking at the picture differently. Combine this with the actual lifespan of XP (15 years) and you have plenty of people getting in the idea that looking at pictures degrades them. – xenoid Apr 17 at 22:57
  • "Other reasons you may have to convert should be evaluated independently." Can you sketch them out? Also, any pointers about Google Drive itself? Do they compress by default? – Antoni Parellada Apr 18 at 17:47
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    I think you should more strongly emphasize the importance of working from a copy versus converting the original image. Whatever the original image format is should be saved permanently and untouched, because whatever changes you make can always be redone with a new copy of the original, but once you've altered the original you can't get it back. – barbecue Apr 18 at 18:36
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For digital preservation, I find the following optimal:

  • Shoot RAW + JPEG.
  • Store both files.

RAW is as close as possible to what the sensor sees. Even PNG has some losses, including losses from denoising and demosaicing algorithms. RAW has none of those losses. For digital photography, anything including denoising and demosaicing is not lossless.

However, RAW requires a capable software to interpret the data. It is not an image, it is raw data from the sensor. It becomes an image only after interpretation.

Software changes over time. Thus, the interpretation of RAW changes. It will probably improve over time, but some changes may actually end up being negative for some rare images. Also, can you after 30 years find a software for the operating systems used then for a 30-year old camera? Perhaps, perhaps not.

By storing JPEG too, you are ensuring you at least have something to work with if the RAW image requires too much effort to convert to a lossless format using the software of the future.

The JPEG takes minimal additional space compared to RAW.

As already explained, there is absolutely no benefit to convert JPEG to PNG as the losses are already there. JPEG cannot be converted to RAW in practice.

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  • Thank you. Any thoughts on detriments of storing (in whichever format) in Google Drive? – Antoni Parellada Apr 17 at 17:48
  • @AntoniParellada You'll find that you soon run out of free space with RAW, thus requiring to pay more. Nothing more than that. I would pay the extra money for RAW storage. – juhist Apr 17 at 18:01
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    The bulk of this answer neither answers the question nor addresses the underlying misconception that led to it being asked. – xiota Apr 17 at 19:07
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    It may be worthwhile to convert the camera's proprietary RAW format to DNG. Adobe supplies a free DNG Converter program to do that. – Andrew Morton Apr 18 at 18:44
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Lots of long answers here.

Should I convert my family pictures from JPEG to PNG?

NO!

but I recently have become concerned about the fact that I read there is progressive loss every time they are opened.

Incorrect, quality is only lost if they are re-saved as JPEG, such as after editing. Never delete/overwrite the original JPEG files

Using a program like Photoshop Lightroom will help you keep a catalog of original images safe, because it stores edits as metadata, and will always create a copy when editing with an external editor.

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