--- abstract: 'I present a new focal-plane analog VLSI sensor that estimates optical flow in two visual dimensions. The chip significantly improves previous approaches both with respect to the applied model of optical flow estimation as well as the actual hardware implementation. Its distributed computational architecture consists of an array of locally connected motion units that collectively solve for the unique optimal optical flow estimate. The novel gradient-based motion model assumes visual motion to be translational, smooth and biased. The model guarantees that the estimation problem is computationally well-posed regardless of the visual input. Model parameters can be globally adjusted, leading to a rich output behavior. Varying the smoothness strength, for example, can provide a continuous spectrum of motion estimates, ranging from normal to global optical flow. Unlike approaches that rely on the explicit matching of brightness edges in space or time, the applied gradient-based model assures spatiotemporal continuity on visual information. The non-linear coupling of the individual motion units improves the resulting optical flow estimate because it reduces spatial smoothing across large velocity differences. Extended measurements of a 30x30 array prototype sensor under real-world conditions demonstrate the validity of the model and the robustness and functionality of the implementation. ' altloc: - http://www.cns.nyu.edu/~alan/publications/publications.htm chapter: ~ commentary: ~ commref: ~ confdates: ~ conference: ~ confloc: ~ contact_email: ~ creators_id: [] creators_name: - family: Stocker given: Alan honourific: Dr. lineage: '' date: 2004-01 date_type: published datestamp: 2004-01-13 department: ~ dir: disk0/00/00/33/77 edit_lock_since: ~ edit_lock_until: ~ edit_lock_user: ~ editors_id: [] editors_name: [] eprint_status: archive eprintid: 3377 fileinfo: /style/images/fileicons/application_pdf.png;/3377/1/Stocker2004a.pdf full_text_status: public importid: ~ institution: ~ isbn: ~ ispublished: ~ issn: ~ item_issues_comment: [] item_issues_count: 0 item_issues_description: [] item_issues_id: [] item_issues_reported_by: [] item_issues_resolved_by: [] item_issues_status: [] item_issues_timestamp: [] item_issues_type: [] keywords: 'visual motion perception, 2-D optical flow, constraint optimization, gradient descent, aVLSI, analog network, collective computation, neuromorphic, feedback, nonlinear smoothing, perceptual prior' lastmod: 2011-03-11 08:55:27 latitude: ~ longitude: ~ metadata_visibility: show note: |- this is a preprint/technical report that will be published soon in a journal. check http://www.cns.nyu.edu/~alan/publications/publications.htm for upcoming versions. number: ~ pagerange: ~ pubdom: FALSE publication: ~ publisher: ~ refereed: TRUE referencetext: |- [1] C. 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Maunsell, “Attentional modulation of visual motion processing in cortical areas MT and MST,” Nature, vol. 382, pp. 539–541, August 1996. relation_type: [] relation_uri: [] reportno: ~ rev_number: 12 series: ~ source: ~ status_changed: 2007-09-12 16:50:34 subjects: - comp-neuro-sci - comp-sci-mach-vis - comp-sci-robot succeeds: ~ suggestions: ~ sword_depositor: ~ sword_slug: ~ thesistype: ~ title: Integrated 2-D Optical Flow Sensor type: preprint userid: 179 volume: ~