Patent ID: 7978907

Claim:
An image analyzer for detecting a target object from image data, the image analyzer comprising: a reference detection unit that detects a reference object included in the image data; a primary detection unit that detects candidates for the target object from the image data by obtaining color information about an attribute of the candidate from the reference object detected by the reference detection unit, performing a histogram analysis on the color information of the attribute of the candidate from the reference object, and determining a reference attribute based on the histogram analysis for detecting the candidates for the target object; a secondary detection unit that specifies a portion including the target object from among the candidates, by using a correlation between a feature of the detected reference object and a feature of the candidates; and an output unit that outputs information representing the portion including the target object specified by the secondary detection unit, wherein a position of the target object is movable with time; the secondary detection unit specifies the portion including the target object, by means of a Bayesian network comprising a dynamic node based on information about motion of the target object, a static node based on information having no relation to the motion of the target object, and a candidate determination node; and the dynamic node and the static node are different from each other in a mode of connection to the candidate determination node, the secondary detection unit calculates a conditional state-transition probability of each node of the Bayesian network by the expression P ( X i k  ⁢ Pa ⁡ ( X i ) j ) = α ijk + N ijk ∑ k ′ ⁢ α ijk ′ ⁢ + N ijk ′ where X i k denotes that a state of a random variable X i of the node is k, Pa(Xi) j represents as j a combination of states of the group of parent nodes X i , α ijk designates a hyper parameter of a Dirichlet distribution, and N ijk denotes a number of occurrences of a combination of states designated by (i, j, k).