Image File Types - Saving and Backing Up Film Scans and Digital Images
I'm looking to better understand the best file type I should be saving my photos to. Currently, I archive all of my DNG files in my external HDs (including final JPEG outputs), but at the same time, I save high resolution JPEGs online as backup and for viewing purposes. On the other hand, I scan my 35mm films at 2400 DPI and save them as JPEGs as well, like the aforementioned, I also save high resolution JPEGs online as backup and for viewing purposes.
I've read in a lot of forums and articles that the best image file type to save and keep photos are in lossless TIF and/or PNG--PNG being a lighter alternative to TIF files.
Provided that I don't have any space constraints, I'd like to keep all of my photos in either TIF or PNG (preferrably PNG to save more space), but given that I can save digital photos in RAW offline (which are way lighter than TIF and PNG files), I can probably stick with that.
My question now is, would TIF and/or PNG be ideal in backing up photos (digital photos online and film scans offline and online)?
Should I even bother what DPI I should be backing them up online (in case of HD failures and what have you)?
What are your thoughts?
I expect this isn't really an APUG question, more 'hybrid' or even digital. However, at the risk of incurring the wrath of the moderators , PNG is not a preferred format for archival storage of images like photographs. While it may be lossless, it's not very efficient as a compression method for photographic images and doesn't support exif (if that's relevant to you).
I work in academic image archiving, where the standard formats tend to be either TIFF or jpeg2000. With jpeg2000 you can compress them using lossless compression, so you can recover the original data unchanged. However, not all of the available jpeg2000 libraries do true lossless compression, even when set to lossless (jasper is guilty of this). If it was me I'd batch convert to lossless jpeg2000 using kakadu, or just back up the DNG files. Some image libraries are actually using lossy jpeg2000 compression, with settings that they feel give effectively unchanged images but offer savings in file storage. This is a topic with a lot of ongoing scholarship and debate.
Print them out and take a picture of them using a film camera.
"There is a time and place for all things, the difficulty is to use them only in their proper time and places." -- Robert Henri
affords 16 bit if massive corrections needed later.
They are huge but if the shots are important, the shots are important.
I also am in the camp that tiff will be readable for longer and Jpg2000 may vanish.
Originally Posted by mcgrattan
What I do with transparency scans:
Scanned as 16 bit TIFF files. I remove any dust but apply no minor corrections (eg curves levels, sharpening). This is saved as my 'original' 16bit TIFF file.
Then for the final scan tweaked (minor sharpening, occasional minor curves / levels) so that it matches the original transparency, nothing more, also saved, my 'final' 16 bit TIFF. Any resizing etc needed for web posting done from this 'final' 16 bit TIFF file.
All my saved files also backed up on external hard drive - I hate scanning and have no urge to do any of this again if hard-drive crashes...
Last edited by coigach; 10-26-2011 at 10:04 AM. Click to view previous post history.
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I use either Printfile or ViewAll. Both are archival.
Originally Posted by Jurgen Estanislao
Nice try. If he didn't get that this was APUG, I doubt that he'll get the sarcasm.
Originally Posted by ic-racer
Hi Jurgen. This subject is off topic for APUG, but is right on for DPUG. You can find the link at the top of the page. Questions about analog workflow are very welcome here though, as are you.