Imagine a fitting room with a "smart" mirror that suggests jeans to go with the red shirt you brought in. It snaps a video so you can compare the image side-by-side with other colorful shirts you try on. It might even show you how the shirt will fit without you having to undress.

A handful of primarily upscale retailers, including Neiman Marcus and Nordstrom, are testing versions of this high-tech fitting room. And experts say the masses will be able to try these innovations at more stores in the next few years as the technology gets cheaper.

This trend is a way stores aim to catch up to online rivals like Amazon.com that are able to gather information on which items shoppers browse and use that to recommend other products. The new technology that enables physical stores to collect much of the same data Relevant Products/Services as online retailers raises privacy questions, but executives say customers are offered a choice and the data is protected.

Stores are tapping into the significant role the often-forgotten fitting room can play in purchase decisions. While 36 percent of store browsers wind up buying something, 71 percent of shoppers who try on clothes in the fitting room become buyers, according, Paco Underhill, a retail consultant. Yet the typical fitting room isn't always inviting: Only about 28 percent of shoppers even walk into a dressing room of a typical clothing chain, Underhill says.

"The dressing room experience in many places has been close to miserable," Underhill said. "There's bad lighting. They're dirty. And they have poor service."

Some companies are working to change that impression. Later this year, Big Space, a technology company, plans to test at an undisclosed clothing chain a new mirror that recognizes the gender of a customer Relevant Products/Services and makes recommendations based on that. Customers also will be able to request or purchase the items directly from the mirror and have them shipped.

Other technologies already are being tested in stores. In recent years, stores that include Bloomingdale's and Top Shop have tested technology that enable shoppers to see how they look in an outfit without trying it on.

The patented MemoryMirror (pictured) from a Palo Alto, California-based company called MemoMi is one of the most advanced in this so-called virtual dressing, a feature that's expected to be tested in U.S. stores later this year. The mirror is outfitted with sensors, setting off motion-triggered changes of clothing. MemoryMirror uses pixel technology that captures even small details such as a wrinkle on a skirt as it moves.

Even for those trying on the clothing, the mirror also doubles as a video camera, capturing a 360 degree view of what an outfit looks like and making side-by-side comparisons. Shoppers can replay the video and share with friends

Earlier this year, Neiman Marcus rolled out the MemoryMirror outside fitting rooms in three of its locations -- Walnut Creek, California, San Francisco and the Dallas suburb of Willow Bend. It is considering activating the "virtual dressing" feature.

John Koryl, Neiman Marcus's president of Neiman Marcus stores and online, said the mirror allows the retailer to for the first time have specific information regarding who tried on the dress and bought it. He said while shoppers must register for a unique account with their email address to use the mirror's features. Any data collected on the mirror's usage is anonymous and aggregated, he said.

A division of online seller eBay that's called eBay Enterprise and specializes in providing retail technology and service also has fitting-room technology that some stores are testing. Designer Rebecca Minkoff's first two stores in New York and San Francisco are testing the new fitting room technology that uses radio frequency identification that embeds data in clothing tags. It will be rolling out the technology when it opens stores in Chicago and Los Angeles later this year, says CEO Uri Minkoff.

It works this way: a touch screen allows the customer to flip through a catalog and indicate which items he or she wants in the dressing room. The customer inputs their cellphone number and the sales Relevant Products/Services clerk texts when the fitting room is ready. When the shopper walks in the dressing area, the mirror recognizes the items and displays the different clothing on the screen.

Minkoff said the two stores testing this technology are selling the clothing two and a half times faster than expected and shoppers are increasing the number of items they buy by 30 percent. "We are creating dressing room therapy," said Uri Minkoff.

EBay Enterprise also is working with Nordstrom, helping the company understand how the technology performs on a larger scale. Nordstrom uses the mirrors in some fitting rooms in Seattle and in San Jose, California, but they work a little differently: Shoppers are equipped with bar code scanning devices so they're able to see what's in stock in the dressing area. "We will listen to the customer as they use the mirror and see what changes make sense to improve the experience," said Nordstrom's spokesman Dan Evans.

The new technology has some consumer advocates concerned. "One assumes that the mirror is not looking back at me unless you are in a fairytale," said Nuala O'Connor, president & CEO of nonprofit Center for Democracy & Technology. "People love new technology as long as they are aware of what is happening to them and have control of their data.

But some customers are embracing it. Wendy DeWald, of San Francisco, spent $1,000 on her first trip to the Rebecca Minkoff store; she's returned a few more times. She doesn't mind sharing some of her personal data to get a better experience.

"I'm pretty blown away," she said. "It's a toy in the dressing room. It enhances the experience."