(Adds Bezos' comments, more details on features)
SEATTLE, June 18 (Reuters) - Amazon.com Inc Chief Executive Officer Jeff Bezos unveiled a "Fire" smartphone on Wednesday equipped with a 3D-capable screen and the ability to recognize objects, music and TV shows, hoping to stand out in a crowded field dominated by Apple Inc and Samsung Electronics.
Bezos, in a rare media appearance, demonstrated three-dimensional display features on the 4.7-inch phone, such as greater depth perception in maps and pictures. Four front-facing cameras track head movements and can shift perspectives depending on a user's activity.
A "Firefly" feature allows users to point the phone at an object, such as a product, or direct it to listen to a song. If the device recognizes it, the user can buy it on Amazon.com if it is sold there.
Shares of Amazon climbed 2.5 percent to $333.67 in afternoon trading from roughly flat before Bezos took the stage.
"What if there were a thousand artists standing by to redraw the picture every time you moved your head?" Bezos asked hundreds of Amazon customers, reporters and industry executives gathered in Seattle for the unveiling.
The smartphone joins Amazon's "Fire" lineup of tablets and streaming devices. It represents the latest attempt to extend its dominance of online commerce into mobile phones, which are increasingly being used to buy items and view video.
It is unclear how "Firefly" or the 3D-perspectives will function in the real world, or how fickle consumers will take to them.
Industry insiders had expected the "Fire" to be far less expensive than the top-selling iPhone and Galaxy devices, after the company sold its Kindle Fire tablets at cost.
Amazon is selling the Fire smartphone on its website for $649 without a contract. From July 25, a 32-gigabyte storage version will sell for $199.99 with a two-year contract on exclusive carrier AT&T Inc. These prices are comparable to the iPhone 5C, though it has superior displays and other features.
The Fire smartphone represents a new area for Amazon, which got its start selling books and has expanded into everything from cameras to grocery delivery. It could also boost adoption of a payments platform.
The Fire is the third device Amazon has introduced this year, after its FireTV streaming device and Dash grocery-ordering wand. In recent years, the company has moved more aggressively into hardware, selling its devices at cost to spur purchases on its website.
Its entry into the smartphone market reflects the growing trend among consumers to view and buy items online. Mobile commerce grew at almost twice the rate of online retail during the first quarter, according to comScore.
(Reporting by Deepa Seetharaman; Editing by Bernard Orr)