发明名称 Method and device for identifying an image acquisition feature of a digital image and apparatus for implementing such a device
摘要 The invention particularly relates to a method for identifying an image acquisition feature of a digital image oriented in a coordinate system having a reference axis. According to the invention, this method comprises the steps of: (A) detecting the contours of each distinctive element of the image; -(B) forming a list including each contour constituted by a rectilinear segment; (C) searching, in the list of rectilinear contours, a pair of significant rectilinear segments; (D) in the case where step (C) is successful, checking for a condition of relative symmetry of the significant rectilinear segments with respect to the reference axis; and (E) producing, respectively in the case where step (D) is successful and in the case where one of steps (C) and (D) fails, a data respectively representative of the presence and absence of perspective in the image acquisition, with respect to the reference axis.
申请公布号 US8837834(B2) 申请公布日期 2014.09.16
申请号 US201013517200 申请日期 2010.12.17
申请人 ST-Ericsson SA;ST-Ericsson (France) SAS 发明人 Chouly Antoine;Merigeault Rhein Sandrine
分类号 G06K9/46;G06T7/00;G06K9/52 主分类号 G06K9/46
代理机构 Coats & Bennett, PLLC 代理人 Coats & Bennett, PLLC
主权项 1. A method for identifying an image acquisition feature of a digital image composed of pixels and oriented in a coordinate system having at least one reference axis (Xo), the method comprising: (A) detecting the contours of each distinctive element of the image; (B) forming a list including each contour constituted by a rectilinear segment; (C) searching, in the list of rectilinear contours, for a pair of rectilinear segments (S1, S2); (D) where step (C) is successful, checking for a condition of relative symmetry of the rectilinear segments (S1, S2) with respect to the reference axis (Xo); and (E) producing, respectively in the case where step (D) is successful and in the case where one of steps (C) and (D) fails, a data respectively representative of the presence and absence of perspective in the image acquisition, with respect to the reference axis (Xo), the presence or absence of perspective constituting said image acquisition feature; wherein step (C) comprises searching in the image for a first rectilinear segment (S1) of maximum length; checking, as a condition for validating step (C), that the length of the first rectilinear segment (S1) is higher than a length lower limit; searching among the remaining rectilinear segments of the image for at least a second rectilinear segment (S2) of acceptable length; and checking, as a condition for validating step (C), that the length of the second rectilinear segment (S2) is at least equal to a fraction of the length of the first rectilinear segment (S1); wherein step (D) comprises determining the slope (θ, θ′) of each of said first and second rectilinear segments (S1, S2) with respect to said reference axis (Xo); checking, as a condition for validating step (D), that the slopes of said first and second rectilinear segments are of opposite signs; and checking, as a condition for validating step (D), that the respective absolute values of the slopes of said first and second rectilinear segments exhibit between each other a deviation at the most equal to a maximum permitted slope deviation (Δθ); and further comprising (F) correcting the orientation of the image by applying to the image a rotation equal to the angle formed, with respect to the reference axis (Xo), by a line having an intermediary slope between the slopes (θ, θ′) of the first and second rectilinear segments (S1, S2).
地址 Plan-les-Ouates CH