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15 November 2016
While we've been testing the FastFoto FF-640, which is Epson's answer to digitizing your shoebox of old prints, Google released its free PhotoScan for Android and iOS to do the same thing but with your phone.
You've always been able to take a photo of a print with your phone, of course. But not a very good photo.
It's difficult to square up the image, to hold focus, to properly light the print, to avoid glare and, well, a lot of things. But you could get still manage to get a photo.
HOW IT WORKS
Well, computational photography to the rescue. Let that smartphone wring its brain out to solve those problems.
You just need to give it a little more data. More shots, in short. One overall image and an image of each corner.
Computational photography may be complex, but the process of using PhotoScan itself is dead simple.
- You take one shot of the whole image just as you used to do.
- Then the app displays four big dots near the center of the screen and asks you to move the circle in the middle over one of them. When you do, it takes a photo and asks you to pick another dot.
- When all four dots have triggered shots, the app processes the data. It took just a few seconds.
Processing looks for glare and tries to find what has been obscured by looking at the other shots. It aligns the four images by matching between 500 to 4,000 feature points and corrects for perspective by aligning tiles of the images.
Once the image is processed, the app displays it. You can then save it to your camera roll and to Google Photos.
You do have a couple of editing options. You can rotate the image or adjust the corners. It's fun to peek at Adjust Corners because you can see how the perspective has been skewed.
But for heavy duty editing, you'll have to resort to a real image editing app like Apple Photos or Google Photos.
WE TRY IT
We downloaded the free app and looked around for some old prints. There were two under some glass on a dresser. Black-and-white prints, in fact.
The dresser was tall so our shooting angle was awkward but you aren't very far away when you copy a print to begin with.
The bigger problem is that it was dark. So we turned on the ceiling light. That cast our shadow over the prints. We stood to the side with the phone's lens on the far corner nearest the light to avoid our shadow and the camera's shadow.
Focus on the whole image wasn't immediately attained. But that didn't seem to matter.
The flash did fire when, after pressing the Shutter button, the lens focused on the image.
Then we followed the dots to capture the quadrants of the image. The phone's LED stayed on as we moved across the image to take the four individual shots.
We especially liked that we didn't have to press the Shutter button again. Just move across the image. As you hit a dot, the phone takes a photo.
The four dots actually force you to capture the four corners of the image as individual shots to be mapped into one that looks like the overview shot.
Still it's five shots per image. If we were doing a shoebox, we'd scream for mercy. The new Epson scanner, in contrast, can just swallow that whole shoebox in a few gulps.
Processing was quick, under a minute an image. The images were all saves as PNGs rather than JPEGs.
On the phone these shots looked better than they do reduced here. We grabbed the images from Apple Photos, actually, to resize them in Photoshop.
But even on the phone we could see a few problems:
- The crop is tight, especially on the vertical image.
- The images are overexposed.
- Neither image is sharp.
- The color is not neutral.
So as photos they don't cut the mustard.
But note what they do manage to accomplish:
- No glare even though there had been glare on each image
- Perspective is corrected
- Focus is even throughout
Which is quite an achievement.
We suspect the poor lighting was a big problem so we dug up a color print and copied that in brighter light.
We didn't entirely escape the glare on this image and while this thumbnail may look sharp enough, the full resolution image isn't. But exposure is better.
We suspect the difference in results is a reflection of the conditions in which the images were taken.
ONE OTHER ISSUE
Google Photos orders your images by the date in the Exif header. For these print copies, that date will be the day you took the photo of the print, not the day the original photo was taken.
So you may want to do this in albums, which you can date later. Here's one workaround we found that explains how to do that.
Google PhotoScan does a remarkable job of copying a print. You can sometimes do better without it but you'll typically do much worse.
Focus and exposure are the two weakest points. But you can help by providing good lighting and holding the phone level and at the same distance from the print for all exposures.
A scanner, however, does a significantly better job of copying a print. Google PhotoScan isn't in that league.
But it will be fun to watch Google try to get there.