51. Old Photographs and Digital Formats
So, you have just inherited a large box of old photos when they cleaned out your grandmother’s house after she parted this world. Now, you would like to digitize some of these photos for posterity. What to do? What format should you use for the digital copies?
The answer is simple: jpeg. No alternatives, really.
There is one, and only one reason to even consider
alternatives: repeated small changes (editing) of jpeg images will introduce gradual deterioration of "photo-mechanical" quality (i.e., the "sharpness"). These “losses” can be ameliorated by proper procedure ("workflow"); as follows:
Scan the original (most garden-variety "office" scanners will suffice) using 300 dpi resolution settings for images that will later be consumed on computer, possibly 600 dpi for high quality material that you might want to print. Save scanning output as jpeg, using the high-end 90% - 95% quality/compression setting. (these numbers are described in photo-editor user interface and what is their range varies from one graphical application software package to another.) I use 600 dpi for scanning my old photos.
Edit to improve the scanned image (in the order given below):
1) Crop and rotate (if necessary), remove blemishes on the original (scratches, fold lines, spots, spill marks....)
in one single "edit session". Save image over the original
scanner output version. This is the file you will archive
forever and might want to go back to if necessary. This is
"out-of-scanner original", "generation-0" file. Most time
spent will be in this step, you don't want to have do this
again.
2) Using "gen-0" file as source, edit to improve tonal range, contrast/brightens (levels, curves...) and/or colour, again in a "single-edit-sitting", save as first generation
derivative ("gen-1" file). This step requires some skill
and practice, until you reach certain level of proficiency,
you might, on occasion repeat it, but each time starting
not with last saved version, but with "gen-0", output of
step (1).
3) Reduce the resolution to fit the display device, possibly
display-medium "ornamentation" (frame, round corners,
watermark, colour-to-black-and-white, monochrome to sepia, add copyright to metadata, remove metadata that should not be included in files leaving your control etc., etc.).
Reduce the jpeg "quality index" (see above) to 75-85%
(low if for computer display, high if for printing).
Deploy - that is, save the file to wherever the image is
made available to consumer - web server, print service
upload site, e-mail attachment... This is the third
generation derivative file, but it is no longer part of
your photo archives, and is not meant to be changed/edited, ever again.
The image manipulation work required in step (1) is great,
typically performed with software tool such as Gimp or
photoshop (used here as a generic term). In step (2) work
factor is low to medium, in step (3) minuscule and often
achieved by using an automatic tool such as ImageMagic.
A few additional notes of interest:
If the jpegs are saved with 90-95% quality/compression index, it will take more than ten import-edit-save cycles to notice degradation. If the above workflow is followed, end-use file will be gen-3 file (i.e., opened-changed-saved only three times).
When editing in step (1), if it cannot be done in "single
sitting", intermediate saves can be done in photo-editor's
internal, no-loss (.xcf in Gimp) format; such files can be
re-opened and saved with no loss of quality. But these files are large and should be disposed of when the step end is reached.
While I would have no problem sending a complete beginner to do a project with a shoebox of prints and nothing but the above instructions and popular guide "Gimp for Dummies" on his way, this is not the case for scanning of negatives or slides. While it would follow the same philosophy, it gets much more complicated very quickly; both in equipment and in software selection. Instructions would also have to be specific to source
material and user's computing environment.
In conclusion, use jpeg. My theory is that if jpeg is ever eclipsed or retired, the digital world will find a way to provide a forward path for me along with the rest of the many users worldwide.
Note – Gimp is a free open-source photo editor that has all the power and capability of Adobe Photoshop. Very powerful and can be a bit intimidating with all its functionality.
Join your local genealogical society and learn more about saving the histories of your family.
Ron Gilmore
Email: rvg3@me.com
Website: https://www.rgenealogy.ca