2003 | Alexei A. Efros, Alexander C. Berg, Greg Mori, Jitendra Malik
The paper "Recognizing Action at a Distance" by Alexei A. Efros, Alexander C. Berg, Greg Mori, and Jitendra Malik introduces a novel method for recognizing human actions at low resolutions, where a person might be as small as 30 pixels tall. The authors propose a motion descriptor based on optical flow measurements in a spatio-temporal volume for each stabilized human figure, which is then used in a nearest-neighbor framework for action classification. The key challenge is handling noisy optical flow measurements, which are treated as spatial patterns of noisy data rather than precise pixel displacements. The method is evaluated on datasets of ballet, tennis, and football, demonstrating successful action recognition and transfer of 2D/3D skeletons. The paper also explores applications such as action synthesis and figure correction.The paper "Recognizing Action at a Distance" by Alexei A. Efros, Alexander C. Berg, Greg Mori, and Jitendra Malik introduces a novel method for recognizing human actions at low resolutions, where a person might be as small as 30 pixels tall. The authors propose a motion descriptor based on optical flow measurements in a spatio-temporal volume for each stabilized human figure, which is then used in a nearest-neighbor framework for action classification. The key challenge is handling noisy optical flow measurements, which are treated as spatial patterns of noisy data rather than precise pixel displacements. The method is evaluated on datasets of ballet, tennis, and football, demonstrating successful action recognition and transfer of 2D/3D skeletons. The paper also explores applications such as action synthesis and figure correction.