With photos, out-of-focus used to be a permanent condition. Not any more. De-blurring algorithms, written by people who paid lots of attention in math class, reduce and sometimes almost eliminate several kinds of blurring: incorrect focus, motion blur, and Gaussian blur.

Moscow-based image processing guru Vladimir Yuzhikov has created SmartDeblur, a Windows application that does a remarkable job of making blurry images less blurry. Basically, the blurred bits in an image follow patterns that can be traced backwards mathematically. Deliberately blurred signs, serial numbers, and licenses can be adjusted enough to make them legible again. If you thought you used enough Photoshop Gaussian blur to mask your car’s front plate before Facebook-posting “Me driving at speed on Cannonball Run,” think again. It also has the potential to make smartphone cameras perform better.

“Many people think that blurring is an irreversible operation and the information in this case is lost for good, because each pixel turns into a spot, everything mixes up, and in case of a big blur radius we will get a flat color all over the image,” Yuzhikov says. “But it is not quite true — all the information just becomes redistributed in accordance with some rules and can be definitely restored with certain assumptions.” In other words, the sharp image isn’t dead, only sleeping.

The before/after samples here look pretty good considering how out-of-focus the before originals were. These are Yuzhikof’s samples. “The result is impressive… but in practice not everything is so good,” Yuzhikov writes on his site. Try it yourself and you’ll see improvement but not necessarily as much as the man who wrote the (code) book got. You may find out of focus images work better than images blurred by camera shake (low exposure speeds, shooting from a moving vehicle).

A new era of image-tweaking apps

In the two decades of digital image editing (Photoshop dates to 1988), we’ve seen all manner of apps and plug-ins to tweak images: stitching software to make many small images into a panorama; HDR (high dynamic range) software that takes three different exposures of the same scene to render more dynamic range; and even tools to make chubby faces thin (Portrait Professional). Interestingly, many apps started as $50-$200 add-ons or became Photoshop plug-ins and later were incorporated into larger apps. Nobody pays for stitching software now; stitching and HDR are even included in some cameras now.

Image editing software typically has rudimentary sharpening tools, such as the Unsharp Mask (it does the opposite of what the name sounds like) and Sharpen filters in Adobe Photoshop. SmartDeblur, based on photo samples, takes image correction to a whole different level than the Photoshop tools. And the price is right — it’s free. But there’s currently no Mac version. Topaz Labs’ InFocus is a $70 deblurring add-on to Photoshop. Nik Software Sharpener Pro is a $200 add-on for Adobe Photoshop and Lightroom, and for Apple Aperture. Google acquired Nik in September, possibly to arm itself with tools to fend off Facebook, so keep watch on the pricing. Robust Deblurring Software is free for non-commercial users. So is Matlab’s Multispectral Image Pan-Sharpening. Wolfram Mathematica ($140-$2,495) has an image sharpening module. Adobe has been working on deblurring tools for Adobe Photoshop and possibly Adobe Lightroom, but it’s not in the most recent, 2012, editions.

On a related but opposing note, we find it quite amusing that Windows 8 actually blurs its text slightly (ClearType), to make it more legible.

Lytro’s retroactive-focus camera

Lytro shook the camera world a year ago with the $400-$500 no-focus Lytro camera that captures all the light rays entering the camera from the field of view, and then lets the user focus or refocus the picture afterwards. Lytro calls them Living Pictures. But they’re effectively 1-megapixel images, or about 1,080×1,080 pixels. For any other camera, that would have been state of the art in the late 1990s, a good choice for shooting a Lauren Hill concert.

As we noted a year ago, Lytro is a great one-trick pony, but the ability to play around with focus is more of a tool for photo hobbyists than picture-takers who just want every picture to be in focus. For them, there are extended depth of field (EDOF) lenses coming that may be more what they want. Pros often want the opposite, choosing heavy lenses with wide apertures that render only a small slice of the image in focus, leaving the background an out-of-focus blend of colors –- the kind of feature SmartDeblur was created to correct.

Now read: CSI-style super-resolution image enlargement? Yeeaaaah!