Cell Phone Image Digitizing
Many times I am asked to "scan" in a bunch of pictures because people think a flat bed scanner (we have two in the room) is the best way. Actually, an SmartPhone is one of the simplest and BEST ways to get images into a digital format. If you need a REALLY high resolution scan at the best quality, you would probably want to get a really good scanner or send your stuff off to a commercial lab, but a cell phone with a camera makes for an easy way to scan and share your images.
Decide on the app to use
Documents - Use a managing app like CamScanner...it is going to cost a few bucks, but it is well worth it because no only does it let you scan and convert to PDFs, it has an easy to use system of managing similar documents.
Pictures for Facebook - Any camera app with a self timer. The built in app works fine, but Awesome Camera (iphone, free) offers a few other features including a self timer.
Hold the camera perfectly steady is the key. Some apps (like CamScanner) even offer a stabilizer that will delay the shutter actuation until the phone is steady. If your app has a self timer, use it. Set it to 2 seconds. This will allow you to press the shutter, then get the camera steady.
Digitizing Darkroom Negative Prints...including Photogram and Pinhole
Place negative image in good, diffused light.
Hold camera as steady and as square as you can possibly hold it.
Open image in an app that allows for "Inversion"
Photoshop (PS Express) is free...and is a good app to have otherwise.
WoWCamera+ $1.99...but goes On Sale occasionally. It's a good app to get, but wait for it to go on sale. Use App Shopper (iOS) to be notified when it is onsale.
I am sure there are others, but this is what I used. Several apps on my phone, including a couple of my favorite camera apps, did NOT have inverse option.
There will be others, but just watch out for downloading any app...just because it says free doesn't mean it is a good one. It may have advertising and Upgrade Nagware. The option to save your image may be restricted unless you buy the app, etc.
Android may have it built in.
Click on the image and go to the Action Icon, select Effects and then Inverse.
If you do not have a smart phone...using any cell phone with a camera. (you generally need 3mp or higher to digitize a document for screen use)
Take the picture
Email the image to yourself.
Open image in Picasa or Photoshop