Google's New Compression Tool Uses 75% Less Bandwidth Without Sacrificing Image Quality (thenextweb.com)

An anonymous reader quotes a report from The Next Web: Google just released an image compression technology called RAISR (Rapid and Accurate Super Image Resolution) designed to save your precious data without sacrificing photo quality. Claiming to use up to 75 percent less bandwidth, RAISR analyzes both low and high-quality versions of the same image. Once analyzed, it learns what makes the larger version superior and simulates the differences on the smaller version. In essence, it's using machine learning to create an Instagram-like filter to trick your eye into believing the lower-quality image is on par with its full-sized variant. Unfortunately for the majority of smartphone users, the tech only works on Google+ where Google claims to be upscaling over a billion images a week. If you don't want to use Google+, you'll just have to wait a little longer. Google plans to expand RAISR to more apps over the coming months. Hopefully that means Google Photos.

Comments

...without sacrificing photo quality

[JasterBobaMereel]

....is a lie, it reduces image quality just in a way you cannot see visually

If all you want to do is look at the image this is fine, but anything else that needs it full quality will be sacrificed

Re:...without sacrificing photo quality

[PoopJuggler]

is a lie, it reduces image quality just in a way you cannot see visually

If you can't see any difference then the visual quality is the same. Don't conflate visual quality with informational purity. Claiming it's a lossless conversion would be a lie, but that's not what they're claiming.

Re:...without sacrificing photo quality

[mjwx]

....is a lie, it reduces image quality just in a way you cannot see visually

If all you want to do is look at the image this is fine, but anything else that needs it full quality will be sacrificed

Well that's kind of the point. They didn't develop this for image manipulation tools... they developed it to save bandwidth on websites. If you cant visually tell the difference, Mission Hay-Fucking-Complished.

Re:...without sacrificing photo quality

[swillden]

....is a lie, it reduces image quality just in a way you cannot see visually

If all you want to do is look at the image this is fine, but anything else that needs it full quality will be sacrificed

Actually I think you could probably see it if the device are using isn't already so high def you can't tell the smallest details anyway. What they do is just request a 1/4 size image and then upscale it. Woo clever.

No, they request a 1/4 size image, then upscale it, then selectively restore details to portions of the image that humans pay attention to. The result isn't much larger than the 1/4 size image, but looks much better to people.

I've been doing something vaguely similar (though not automatically) for years in my portrait photography. I selectively sharpen (actually, oversharpen) key facial features (especially eyes) that are the things that people focus on when looking at a portrait. This makes the whole image seem sharper and more vibrant, though it isn't. In fact, if the entire image were sharpened in the same way it would look terrible. This is especially useful when I shoot with a soft-focus filter which creates a very nice dreamy effect but can make the subject look dull. Soft focus plus sharpened eyes (and, often, lips -- it depends) make a beautiful portrait which people find more appealing and "realistic" than without the phony sharpening. Similarly, reduced overall resolution with detail retained in the right places makes an image look as good as the full resolution version, even though it's not.

Re: ...without sacrificing photo quality

[Miamicanes]

How well do Google-compressed images deal with enlargement compared to JPEG, JPEG2000, etc? It's nice to say a new algorithm reduces file size without visual consequences, but compression artifacts can manifest themselves in new, unforseen ways. And future upsizing algorithms might end up being able to get better results from one due to "useless" data the other discards.

Case in point: VHS had a nominal resolution of approximately 160x480 or 512 (with color resolution that barely approximated 40x480/512). But with extreme oversampling of a wider tape path (so you also capture unintended sideband artifacts), you can clean up & resample the video in ways that would be frankly *impossible* if your only remaining source copy was literally a 160x480/512 mpeg-1 capture.

This is a big deal for preservation of analog media. It's deteriorating by the week, but for videotape in particular, there's no good way to massively oversample a decaying source in a way that will let us restore it better in the future. What we *need* is a videotape capture device with a dense array of read heads the full width of the tape, in at least two staggered rows (so row 2's sensors are centered between row 1's sensors), so the state of the entire tape can be captured (the dense array is needed because VCRs recorded diagonally via rotating heads to increase the tape speed relative to the read head... it "kind of" worked, but the capture quality with normal VCRs is *profoundly* impaired if the capture VCR's tracking deviates from the recording VCR's tracking... and the recording VCR's tracking ITSELF might have been "wobbly". We now have the ability to make dense read heads, and sufficiently-cheap phase-change magneto-optical storage space (eg, non-LTH BD-R) to do high-density two-dimensional linear capture so the tracking can be handled after the fact via software.

This isn't sci-fi. There are already floppy drive controllers that can use a normal PC quad-density floppy drive to oversample a 5-1/4" c64/apple II/etc floppy (~25 sectors/track, ~35 tracks at 40-track stepping) at 50+ sectors/track and 80 track steppings. They can recover data from old floppy disks that would have been *unreadable* by the original drives & computers **years** ago. And with some floppy mods to give you 160 or 320 track steppings and slow down the rotation speed, even more discs become readable. Not to mention, even the lesser method can trivially overcome disc-based copy protection (most of which depended on storing data in ways that old drives could semi-reliably read, but couldn't reliably/easily write (or wouldn't, if you used the official kernel/OS/BIOS/API).

Anyway, the point is, for capturing decaying analog content from decaying media, compression is BAD if you ever want to be able to restore or enhance it someday.

Re:...without sacrificing photo quality

[swillden]

+1.

It's really impressive how much a difference sharp eyes make. I like taking close-up portraits with my 85mm f/1.4 on a full frame sensor. 99% of the whole picture is basically completely out of focus. If the other 1% falls on the eyes, the picture looks perfectly sharp. It's junk otherwise.

Yup. When people look at portraits, they look first, last and middle at the eyes. My slight oversharpening brings out detail in the irises and lashes that people don't consciously notice but really make the image "pop".

Most of photography is understanding how humans see images and enhancing (with various techniques, including composition, focus, lighting, post-processing etc., etc.) the portions that the photographer wants the audience to look at, in ways the audience finds compelling. In hindsight it's obvious that you can take random photos and go the other direction, losing detail that no one cares about, without degrading human perception of the image. Doing it well requires some understanding of the content of the image, though, so it takes a smart-ish system.

Better article

[alexhs]

Summary's links are fact-free ads.
I found this one, that has the merit to link to the arXiv article about the process.

Example of the JBIG2 compression fiasco

[Guppy]

Let's hope Google has had the forethought to have the image recognition algorithm pre-screen for images containing numbers, letters, and diagrams. Pattern-matching compression can be pretty scary when it decides two patterns are close enough:

http://www.dkriesel.com/en/blo...