While some grocery chains like Big Y and Kroger have done away with self-checkout lanes, other retailers have welcomed them in - but with a bit of added security, thanks to a software program that analyzes store video and tracks theft.

Scan-It-All is a video recognition technology that's automated to analyze a retail store's security videos in real time. It works by comparing the number of items a customer has in the cart with the number of items being scanned.

"It can see the customer has five items but has only rung up three of them," said the program's creator Malay Kundu, also the founder and CEO of StopLift Checkout Vision Systems. "We just make sure people aren't stealing."

When an incident occurs, the program immediately notes the transaction and alerts a store employee.

Kundu, who created Scan-It-All nearly three years ago, said his program was watching thousands of checkout lanes across the U.S. and that he'd seen a sharp increase in retailers demanding his technology.

As retailers are ushering in self-checkout stations to reduce labor costs, he said, they are finding themselves faced with the possibility of increased thefts.

"We do see as much as five times the rate of loss [including theft] at self-checking," as compared to stations where there are cashiers, he said.

Last week, law enforcement in New Jersey ended a multistate theft ring that led to more than $100,000 in losses at about 70 Home Depot stores from New York to Virginia. The thefts allegedly occurred at self-checkout lanes as the thieves scanned cheap items and bagged the more expensive ones, despite the presence of attendants.

Kundu said that most retailers hired employees to staff self-checkout lanes for customer service purposes.  But if an attendant is helping one customer, he said, that leaves the other customers to ring up their items without being watched.

"It's one step beyond saying 'Let's use the honor code,'" he said of self-checkout. "No one is necessarily watching."

According to Scan-It-All's online tally, it has recorded nearly half-a-million cases of scan avoidance - among staffed and self-checkout stations - over the last three years.

Kundu said customers usually managed to avoid scanning by leaving items in carts, weighing items by the pound though they had individual price tags, and by "sweethearting," in which customers and cashiers don't scan the item at all.

"It's not always the really expensive item," he said. "We see people [stealing] random items just because they can."

In an email, Home Depot said it could not "get into that level of detail about our security measures" when asked whether it used a program similar to Scan-It-All. But the company said it would not  be removing its self-checkout lanes; customers prefer them.

The Associated Press contributed to this story.