Checking out Photoshop for Chromebooks: Network-computing revived

In the computing industry's last chapter, Sun Microsystems had a motto: "The network is the computer." The phrase was open-ended enough to mean just about anything involving its main business, which was selling servers, but it wasn't enough to keep Sun from faltering and being swallowed up by Oracle.

It's vision is coming true now, though. Exhibit one: Photoshop now runs on a Chromebook.

The traditional version of Adobe Systems' flagship software, which has become the industry standard for photo editing, is a fine example of old-era software dating back to the time when Microsoft ruled the roost. Though it's one of Adobe's somewhat misleadingly named "Creative Cloud" products, it actually run on a PC (and not from the cloud). Thus, it benefits from every processor cycle and megabyte of memory. Google Chromebooks -- laptops running Google's Chrome operating system software -- are from the very different era of Web-based software, where programs are housed in the cloud and run in the browser.

So how do Chromebooks and Photoshop come together? By running Photoshop on one of Google's central Compute Engine servers and piping the screen contents over the network to a Chromebook using a modified version of Google's Remote Desktop extension for Chrome. The laptop sends mouse clicks and keystrokes back up to the server for interpretation. It's very much the idea Sun failed to promote with its Sun Ray "thin clients," but now it's done with a Chrome extension and a modest network connection of at least 1 megabit per second (Mbps).

It's not clear yet how widely Adobe will push the technology and how eagerly the company's core creative-professional market will embrace it. But it does show that steadily improving technology can breathe new life into old approaches.

Adobe announced what it called Photoshop Streaming in September in a six-month pilot program for customers in the education market. It works on both Chrome for Windows and on Chromebooks, but Adobe is aiming the software chiefly at the Chrome OS devices, which are relatively popular in schools.

High performance from a $200 Chromebook

"Even $200 Chromebooks are fully capable of decoding a video stream in real time," said Kirk Gould, an engineering director at Adobe. "You get the same experience as a high-end desktop user would." That's important, given that many students [use] hardware that doesn't meet the minimum system requirements for running Photoshop, he adds.

Education customers also appreciate that Photoshop Streaming is centrally managed, with Adobe and Google automatically pushing out the latest updates, so school administrators don't have to worry about keeping machines up to date. Photoshop Streaming is conceptually well aligned with Adobe's Creative Cloud subscription program, which through monthly payments makes it easier to offer frequent updates and software that's sold as a service rather than as a packaged bunch of files that's purchased one time and installed on a specific computer.

Although Adobe limits Photoshop Streaming to paying Creative Cloud customers, it's not actually part of the Creative Cloud subscription. "There is no timeline for when streaming Photoshop will be available to Creative Cloud customers," the company said.

Adobe isn't moving away from traditional Photoshop, locally installed on a PC, though. "This is not a replacement for the classic version of Photoshop," said Victoria Selwyn, the Adobe senior program manager in charge of the project.

She wouldn't say how many customers are so far using Photoshop Streaming. "It's a small group now. We wanted to focus on feedback," she said. "We'll be gradually ramping up over the next six months."

Adobe's Creative Cloud subscription service costs $50 per user per month for a full-year commitment that grants access to all Adobe's software. The company offers a discounted $30 price for education customers and a $16 promotional price for them through November 28. Photoshop Streaming isn't generally available during the current testing period, but education users who want to try it can apply for access to the program.

Demo: Mostly like the regular Photoshop

In a short demonstration, Gould showed how Photoshop Streaming works. People launch the Chrome app, available through the Chrome Web Store (but for now only to those with permission). Photoshop Streaming starts in a window of its own without the usual browser-window framing. That makes it look like a regular standalone application and offers the most screen area possible to the software. That's important for lower-end Chromebooks that often have smaller screens, Gould said.

Launching the app, which invokes an instance of Photoshop on a Google virtual machine in a Google data center, doesn't take long -- indeed, sometimes it's faster than on a local PC, Gould said.

Opening and saving files is the same as with regular Photoshop, only files are stored on Google's servers reached through Google Drive. That means opening files and saving files isn't constrained by a person's network connection.

Most of a Photoshop Streaming demo is, frankly, boring to anyone who's seen Photoshop already. It's the same old thing for the most part. The biggest difference is that Google's virtual-machine infrastructure can't use graphics-processing chips, which handle an increasing amount of work in Photoshop but which aren't essential for most tasks. 3D graphics are a problem, though, and Adobe is working with Google to shore up the weakness.

Another difference is printing, since Chromebooks don't run local printer drivers the way Mac and Window machines do.

Adobe also is considering how to get Photoshop Streaming to work with other cloud-synced file storage technologies, such as the one Adobe itself operates for Creative Cloud customers.

Not a Web app

The software works by sending a compressed video signal to the Chromebook, Gould said. The Chrome app relays the user's mouse, trackpad and keyboard operations to the Google server to actually control the software.

"We stream the UI down and stream the events back up," Gould said.

Photoshop Streaming uses Google's VP8 compression technology, which is built into Chrome. "VP9 is an open candidate being worked on," Gould added, but it's not in use now. The VP8 successor offers higher compression efficiency but that takes more processing power to compress.

Browser makers including Google are pushing to make the Web a more capable foundation for software, including apps that can tap into the graphics processor, run background tasks and work even if there's no network connection. But the Web isn't powerful enough to run full-fledged Photoshop today, even if Adobe could justify the monumental engineering resources that would be required.

Streaming over the Web, though, is attainable. Adobe isn't the first to try it -- indeed, Google touted companies like Citrix that offer thin client and virtualization technologies so customers can make better use of Chrome OS devices. Photoshop, however, is one of the highest-profile, demanding programs around.

"Our focus is really making this a platinum experience comparable to a local install of Photoshop," Selwyn said.

Sun tried for years to get the Sun Ray to succeed, but ultimately failed. Today's technology means the idea lives on.

Update, November 24 at 10:55 a.m. PT: Clarifies that Photoshop Streaming isn't part of the Creative Cloud subscription offering, though educational users must be Creative Cloud members to be eligible.