Factorization with Uncertainty and Missing Data: Exploiting Temporal Coherence

Neural Information Processing Systems

The problem of "Structure From Motion" is a central problem in vision: given the 2D locations of certain points we wish to recover the camera motion and the 3D coordinates of the points. Under simplifiedcamera models, the problem reduces to factorizing a measurement matrix into the product of two low rank matrices. Each element of the measurement matrix contains the position of a point in a particular image. When all elements are observed, the problem can be solved trivially using SVD, but in any realistic situation manyelements of the matrix are missing and the ones that are observed have a different directional uncertainty. Under these conditions, most existing factorization algorithms fail while human perception is relatively unchanged. In this paper we use the well known EM algorithm for factor analysis toperform factorization. This allows us to easily handle missing data and measurement uncertainty and more importantly allows us to place a prior on the temporal trajectory of the latent variables (the camera position). We show that incorporating this prior gives a significant improvement in performance in challenging image sequences.


Follow your favorite local sports teams with Apple's latest TV update

Engadget

Its venerable phone line wasn't the only newly minted product Apple showed off at the iPhone 8 event on Tuesday. Eddie Cue announced onstage that the company will expand availability of its TV app to seven new countries by the end of the year and will be adding local news and sports programming as well. The TV app will be available in Australia and Canada next month, the spread to Germany, France, Sweden, Norway and the UK by the end of the year. US sports fans (that is, those that live in the country), will be able to track their favorite teams and have Apple TV push an on-screen notification whenever a game starts. By the end of the year, Apple also announced that users will be able to ask Siri directly to switch to a game.



Sonos reveals $199 smart speaker with Alexa and Google AI

Daily Mail - Science & tech

Sonos has unveiled a smart speaker that works with both Google and Amazon's AI assistants. The $199 Sonos One is voice controlled and works with 80 streaming services. It is the first consumer gadget to work with multiple voice AIs. The $199 Sonos One is voice controlled and works with 80 streaming services. The new speaker is driven by two Class-D digital amplifiers, one tweeter, and one mid-woofer.