| US 7,502,053 B2 | ||
| Information-processing device and information-processing system | ||
| Keiichrio Kagawa, Ikoma (Japan); Jun Ohta, Ikoma (Japan); Yuki Maeda, Ikoma (Japan); Yasuo Masaki, Ikoma (Japan); Hideki Tanabe, Daito (Japan); and Yasunari Miyake, Daito (Japan) | ||
| Assigned to Japan Science and Technology Agency, Kawaguchi-shi (Japan); National University Corporation NARA Institute of Science and Technology, Ikoma-shi (Japan); and Funai Electric Co., Ltd., Daito-shi (Japan) | ||
| Filed on Jul. 21, 2006, as Appl. No. 11/490,259. | ||
| Claims priority of application No. 2005-220995 (JP), filed on Jul. 29, 2005; and application No. 2005-241021 (JP), filed on Aug. 23, 2005. | ||
| Prior Publication US 2007/0070060 A1, Mar. 29, 2007 | ||
| Int. Cl. H04N 5/228 (2006.01); H04N 5/335 (2006.01); G01S 3/52 (2006.01) | ||
| U.S. Cl. 348—222.1 [348/208.4; 348/294; 345/418] | 11 Claims |
| 1. An information-processing device having the following functions:
performing free-space optical communication to receive predetermined pieces of information from a remote transmitter device
having a light source that emits light containing at least the aforementioned pieces of information;
capturing an image of a certain imaging range; and
obtaining position information of the light emitted from the light source of the transmitter device present within the imaging
range in parallel to capturing plural frames of images of the same imaging range,
and the information-processing device includes:
a) an imaging device including a photo-receiver having a two-dimensional array of normal pixel cells, each of which performs
photoelectric conversion, and a readout circuit for reading out a pixel signal produced by the photoelectric conversion at
each pixel cell;
b) a binning processor for creating a set of binned images having different resolutions from each frame of the image, where
each binned image is created using signals of expanded pixel cells, each of which is created by virtually adding pixel signals
of adjacent pixel cells selected from all the normal pixel cells of the imaging device;
c) an evaluator for processing the signal of a given normal or expanded pixel cell to determine whether the pixel cell is
receiving the light emitted from the light source, by analyzing a predetermined number of frames of images that are temporally
adjacent to or in proximity to each other and calculating an evaluation index that reflects a presence of the emitted light;
and
d) a pixel cell locator for performing a process including the following steps:
(d1) locating one or more expanded pixel cells that are receiving the light emitted from the light source within the binned
image having the lowest resolution created by the binning processor, based on the evaluation indexes that the evaluator has
given to the expanded pixel cells of the binned image concerned;
(d2) defining a limited range within the binned image having the next lowest resolution, including the one or more expanded
pixel cells located in the previous step;
(d3) locating one or more expanded or normal pixel cells that are receiving the light emitted from the light source within
the aforementioned limited range of the binned image, based on the evaluation indexes that the evaluator has given to the
expanded or normal pixel cells included in the aforementioned limited range; and
(d4) returning to step (d2) until one or more normal pixel cells that are receiving the light emitted from the light source
are located in step (d3).
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