Since I have an old 2nd generation iPad that is collecting dust, my first inclination was to install PhotoScan on it to avoid sucking precious battery power from my iPhone. However, I learned that my iPad was not supported, so I installed PhotoScan 1.3.1 (posted 2/21/2017) on my iPhone 6 Plus which currently runs iOS 10.2.1.
After watching a brief tutorial, I found the scanning process to be very intuitive and easy to learn. The flash was turned on by default, and although there is an option to manually disable it, I left it on. A wizard directs you to first capture the entire photo (the “reference frame”) and then move your camera over each of the 4 corners of your photo. This enables PhotoScan to “see” your photo from multiple angles so that it can detect and remove glare from the final composite image. See this video for a quick overview of the computational photography algorithms that PhotoScan uses to remove glare.
One thing I learned through trial and error was that PhotoScan sets the composite image to portrait or landscape orientation based on how you last oriented your mobile device before holding it flat for scanning. With this in mind, you can scan landscape prints in landscape orientation and portrait prints in portrait orientation to maximize the resolution of your final images. Scanning a landscape print in portrait orientation will result in a much smaller final image.
I did receive a “Couldn’t complete scan” error message for 1 of my photos, but it seemed to be a fluke because it successfully scanned on my 2nd attempt.
Regarding image quality, the first thing I noticed was that PhotoScan does a great job of eliminating glare (as advertised). Image resolution was approximately 2000x1400, with JPG files approximately 400K in size. Note that PhotoScan boasts higher resolution scans for iPhone 6S, SE, and 7 starting with version 1.2 on 12/15/2016. One downside of PhotoScan’s image acquisition method is that it allows prints to assume their natural curvature, unlike a flatbed scanner which presses prints flat against the glass bed. In some cases, the curvature can be very noticeable, such as in this image (look closely at the edges):
On the plus side, PhotoScan automatically crops the images, although in some cases I feel like it is a little more aggressive with the cropping than I’d like it to be (eg, some of my old photos have dates imprinted on the white borders, but they were usually cropped out of the final image). PhotoScan also claims to automatically enhance and rotate images, although I am not sure if I noticed the enhancements, and I don’t think automatic rotation fixed many of my problems.
I knew that PhotoScan would consume a lot of battery power, but I was a bit shocked at how quickly my battery drained. I went from 35% to 20% in a matter of minutes. When prompted, I turned on Low Power Mode, which I typically do when my battery hits 20% (if I don’t already have Low Power Mode turned on). I noticed that scanning performance was very sliggish in Low Power Mode (eg, the circles took longer to render and seemed to have difficulty tracking the positioning of the lens) so would not recommend Low Power Mode while scanning. If you’re planning to scan a lot of photos, you may need to plug in your mobile device. While being plugged in solves a power problem, the downside is that you will be tethered to a charging cable which you need to ensure does not obstruct your camera’s view.
Saving images to my iPhone was done with a simple finger tap, and since I also have Google Photos installed on my phone, I was able to immediately backup my scans to Google Photos.
As compared with a flatbed scanner, Google PhotoScan was lightning fast. I scanned 104 prints in about 90 minutes. This includes the time that it took me to remove the photo from its album, scan the photo, and re-insert the photo into its album. I estimate that my digitization workflow with a flatbed scanner (TIFF scans at 600 dpi) and PhotoShop processing (eg, cropping, color correction, saving as JPG) would take around 3-5x as much time.
In summary, Google PhotoScan applies super cool technology to make it quick and easy to digitize old print photos. Tremendous gains in speed are equally offset by compromises in image quality. I personally don’t see a clear winner in the contest between flatbed scanners and PhotoScan. Rather, the decision to use one workflow or another will depend on my needs at the time. For projects in which I value speed and can sacrifice image quality, PhotoScan may do the job sufficiently well. For projects in which I need higher quality images, I will probably stick to my flatbed scanner and manually post-process the images.
What are your impressions of PhotoScan?
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