Device helps visually impaired ‘see’ groceries

Graduate student Siddharth Advani displays a webcam-equipped haptic glove he helped design to help people with vision impairments shop for groceries. (Credit: Patrick Mansel)

A trip to the grocery store is usually a simple in-and-out 15 minute exercise. But for people who are blind or have limited vision, it can be a major chore.

“You always have to find someone at the store to help you,” says Michelle McManus, president of the Happy Valley, Pennsylvania, chapter of the National Federation of the Blind. “Then you have to explain exactly what you want—and hope the person helping you is diligent about getting it right.”

Researchers want to help visually impaired people shop independently by creating machines that can interpret a complex visual scene much as the human brain does.

Third Eye device
When the Third Eye’s vision system recognizes an item the shopper wants, it makes different areas of the glove vibrate to direct the shopper’s hand toward that item. (Credit: Patrick Mansel)

Ambitious vision

The new work is part of Visual Cortex on Silicon, an endeavor that includes materials design, brain circuitry, and more. Research is underway on several fronts at the same time, with new findings from each field shedding light on the problems in other fields. What neuroscientists learn about the architecture of the mammalian visual cortex helps computer scientists design circuits that reflect the way the brain works.

The project’s formal name refers to the goal of creating a digital, silicon-based electronic system that performs like the human visual cortex, the part of our brain that processes and interprets visual information.

The project also has an informal name, “Third Eye,” inspired by the Hindu god Shiva, whose third eye fills the universe with kindness and spews fire to dispel evil. The name suits both the metaphoric and practical aims of the project: If successful, the project will provide its human operators with additional, often enhanced, visual information that will make their lives easier and safer.

Visual Cortex on Silicon addresses three “domains” or end uses, each of which will augment human vision in particular ways. Third Eye-AR (Augmented Reality) and Third Eye-DA (Driver Assistance) will aid in the recognition of objects and people in a variety of settings, including busy streets and urban battlegrounds. Most of the team’s effort in its first year has gone into the third domain, Third Eye-VI, where the aim is to develop a system coupled to a wearable device that will help visually impaired people do their grocery shopping.

Pay attention

The “million-dollar question” in all three projects is whether the abilities of a cognitive system, be it electronic device or human brain, are due more to its hardware/structure or its software/algorithms, says Vijay Narayanan, distinguished professor of computer science and engineering at Penn State. He and colleagues are exploring multiple solutions to this question, ranging from new software that can run on existing processors to new hardware “fabrics” that have the potential to learn on their own.

The researchers’ goal is to develop a system that will recognize that an object it sees is new to it, and store that object in memory. If it encounters the same or similar items enough times, that category will take on more importance. At some point, the system may prompt its human operator to give the item a name and tell the system where it fits in its collection of all known items.

A major challenge in all three domains is to create a system that will know what to pay attention to within a crowded visual field. The human visual cortex has two general modes of attention, Narayanan says.

The “bottom-up” mode is akin to browsing, where we take in the scene without looking for a particular item—until something catches our eye because it stands out from its surroundings, like a face we recognize in a crowd or an orange sale sticker on a grocery shelf. In “top-down” mode, we’re looking for a specific item and our eyes are drawn to things or qualities (size, color, shape) that we know resemble that item.

Third Eye scientists are trying to devise a machine vision system that can operate in either mode or combine the two, depending on the situation. Their major challenge is how to get the system to deal with a complex scene. For several years now, electronic image systems have been able to pinpoint faces and chunks of text in a scene—unless the scene is too cluttered. Scientists says what’s needed is a system that can direct its attention to significant objects amid a hodgepodge of irrelevant items, just like the human visual system does.

Ignore the chatter

But how does the human brain control visual attention? This is where the neuroscientists in the project have provided essential insights.

“If you want to focus on something, you could amplify just the signal, or you can make everything else ‘chatter’ so the signal is the only voice you can listen to,” says Narayanan. “The brain does it both ways. It amplifies this portion of focus and it also actively suppresses these other things that are not of relevance.”

That discovery is a profound advance in research, Narayanan says. The challenge now is to create a machine that can do both.

The new system will need to identify, in very specific terms, those objects it recognizes as being important. When the task at hand is grocery shopping, an obvious way to do that is to use barcodes. The technology for reading them is already well-established, and shopper-assistance devices using it are already being tried.

Trouble with barcodes

But that approach is far from perfect. McManus, who is also an information technology consultant at Penn State, has little good to say about barcode-based recognition. The scanners work, she says, “but you have to find the barcode.” Every shopper, sighted or not, has probably had the experience of waiting while a cashier struggles to find the barcode on a package and get the scanner to read it. A visually impaired shopper carrying a scanner would have to take an item from the shelf and keep turning it around until the scanner finds and reads the barcode.

“If the box you show it is not the right thing, you have to try another, and keep trying until you get the right one,” says McManus. Multiply the frustration of that process by however many items you’re shopping for, and a simple trip to the store becomes a maddening ordeal.

A better solution is what the Third Eye team is working on—a device that can actually read the labels using recognition skills such as reading and interpreting text and identifying logos and images.

Barcodes can, however, be useful in a supporting role. Jake Weidman, a graduate student in information systems and technology, says the team incorporated barcode recognition into its Third Eye prototype as an optional back-up to give shoppers a way to make sure they had the right item. In their first run-through with the system, visually impaired shoppers attempted to verify items via barcode about half the time.

Corn flakes or frosted flakes?

Eventually, the Third Eye system will be so good at recognizing products that shoppers will be able to fine-tune the degree of match between an object it sees on the shelf and an object in the system’s memory, Narayanan says. With a low degree of match, Third Eye might consider Corn Flakes and Sugar Frosted Flakes similar enough to be the same; with greater stringency, the system would not judge them to match, or might offer them as a potential match the shopper might want to consider.

As of December 2014, the system could recognize 87 grocery products with a high degree of precision—necessary if the system is to be useful.

“If it just says ‘cereal’ or ‘dairy,’ it’s not going to help anyone,” he says. “If you want tomato sauce, we need to know if it’s Prego tomato sauce. Is it organic Prego tomato sauce? That’s the fine level of detail we need, and that’s part of the challenge we face.”

Devising a system that can recognize a useful number of objects within a cluttered visual field is only half the problem. The other half is making sure the system actually helps the people it is meant to help.

“We’re studying shopping with visually impaired people: how they organize the task and how they think about it,” says Jack Carroll, distinguished professor of information systems and technology. “What’s difficult about it, what’s rewarding about it, what’s meaningful about it? Because what you don’t want to do in supporting an activity technologically is make it less rewarding, less meaningful, or more challenging.”

‘Wizard of Oz’ approach

Carroll and graduate students Jake Weidman and Sooyeon Lee have been working with the Sight Loss Support Group of Central Pennsylvania, the local chapter of the National Federation of the Blind, and visually impaired high-school students who came to campus last year for a three-week crash course in independent living. They were pleased to find out that grocery shopping was an excellent choice for the Third Eye’s first application.

One thing the visually impaired students helped them with was answering the basic question: what’s the best way for the Third Eye system to guide a visually impaired shopper toward items she might want?

To answer that question, researchers used a “Wizard of Oz” prototype. They had students wear a chest-mounted iPad that would see grocery items on the shelves and transmit the images to Weidman in a nearby control room. Based on what he saw through the iPad’s camera, Weidman would give verbal instructions to the student.

“If you remember, in the movie there’s a little guy behind a curtain who’s creating the appearance of a wizard, but there isn’t any wizard, there’s just a guy behind the curtain,” says Carroll. “In a Wizard of Oz prototype, there is no system. There’s the appearance of a system”—in this case, Weidman giving the shopper verbal feedback as the Third Eye device might do. By following scripts that offered different kinds of information and different wording, the researchers were able to evaluate what kinds of guidance the students preferred.

“We looked at whether it’s more desirable to give shoppers more directive feedback with respect to what the items were, where the items were, and where they should be directing their attention, or whether it would be good to give them more open-ended feedback,” says Carroll. “There was a clear preference for the browsing dialogue.”

The Third Eye system could eventually do both, giving the shopper general information about what it sees while browsing and then, at the shopper’s request, providing guidance to pick up a wanted item.

‘Eye’ in the palm of your hand

Verbal feedback is a good way to go in browsing mode, but for selecting specific products it seems clunky—”Move your hand two inches to the right and six inches forward.” So researchers developed a more subtle, elegant, and private form of direction: a haptic glove that guides the user’s hand toward the chosen item by vibrating at different strengths and in different positions on the hand.

So far, people who have tried the glove have learned quickly—usually within five minutes—to respond smoothly and accurately to the vibrations.


The glove also gave the team a better place to put the system’s camera. Instead of being strapped to the shopper’s chest, the small webcam is attached to the glove at the base of the palm. When the hand reaches out, the “eye” sees what the hand is pointing towards and the system gets a continuous view of what’s on the shelves near the shopper.

Researchers will soon launch a new trial with visually impaired volunteers to further refine the system. For instance, what’s the best way to guide shoppers looking for stacked items such as cans of soup? The shopper needs to pick up the can on top; if he grabs a can in the middle, the stack will tumble down.

In related research, graduate student Sooyeon Lee is working with other volunteers to learn more about how visually impaired people handle groceries at home: where they store and how they organize goods, how they know when supplies are running low, and how they maintain a list of items to buy on their next trip to the store.

Narayanan is already thinking about how the Third Eye-VI device could be made available to the people who could benefit from it.

Businesses might buy one or two of the gloves for their visually impaired customers to use, just as many stores now have motorized scooter-carts for their customers who have trouble walking. They could keep the devices updated with sale prices and locations of items. When a shopper scans in a list of items to be bought that day, the system might even suggest an alternative if a different brand of a list item is available for less money.

Source: Penn State