I am thinking about digitalization of my photos in case something bad happens to them. Photos are 15 cm long and 10 cm wide. I will do it with my HP DeskJet Ink Advantage 4535 scanner. I want to have some tips about: dpi, how to properly put photo on scanner bed (layout), cropping or not cropping photo = meaning leaving photo with blank area around (which is best solution in this case), using different formats, media storage (SSD or HDD, cloud). Thank you for answers.
Before you trust your photos to a scanner, maybe you should check it, scanners from all-in-one printer/scanners are mostly designed to scan documents, color fidelity may not be their top characteristic. Some also introduce transversal distortion, are slightly misaligned, or do not scan to the very edge of the scanner bed. All this can be checked by scanning squared paper with a few arrows drawn to the edges, carefully tucking the sheet along the side of the scanner bed. You can then check:
- That you see the tips of the arrows
- That the vertical lines are indeed vertical in your image editor
- That the intervals between the first vertical line and the others follow a linear progression. No home-grade scanner is perfect, so expect to find slight inaccuracies, that won't really matter. But this can also reveal some more problematic ones.
- Scanning at 600DPI will produce decent 8Mpix images, good for most purposes.
- Usually one tucks a size of the photo along a side of the scanner bed. But you can discover that your scanner is slightly misaligned that way (something scanning squared paper will also show).
- Cropping is better/cleaner even if the un-cropped bits are likely to be very easily compressed and not add that much to file size. I advocate cropping because it makes you look at the scanner output when you can still fix things (misalignment, etc...)
- Image file format:
- TIFF is OK, but if you use JPEG compression in the TIFF you have to be able to control the compression/quality level). Using high-bit depth (16-bit or more) is likely overkill given your scanner.
- JPEG is adequate at good quality levels (90-95). At 8Mpix your image files should be about 2MB, if they are below this you are possibly compressing too much.
- PNG is lossless but the compression algorithm is slow, and won't find much to compress in a photo.
- File size shouldn't be a concern given the size of mass storage these days, unless you save to the cloud and you have a slow link.
- You can use the cloud as a secondary backup, but don't put too much trust in it. Unless you pay a dear price you'll discover that the provider doesn't feel too concerned about the safety of your data. Also, writing is cheap, reading back can be expensive.
- Ideally you want at least two media, not kept in the same physical location (leave one with a parent/friend, or in your office)
- The most reliable long term storage is the old-fashioned hard-disk.
Few fast recommendations:
- try to align the photos to scanner borders, this will help you to avoid rotation (to strait)
- scan at 600 DPI, in specs I see 1200DPI but have my doubts how real is this. Warning, each file will be around 26MB.
- scan only the photo, normally you do not need the entire A4 format (297x210 mm) for 150x100mm. If photo have border you can include it in to the scan.
- scan on 24 bits
- store as PNG or uncompressed TIFF. With TIFF you can add in one file two images - front and back if you have important info on the back you want to keep
- store on at least 3 places, disk, removable media and cloud