METHOD FOR LOCALISATION OF ROAD SIGNS AND RECOGNITION OF THEIR GROUPS AND SUBGROUPS Russian patent published in 2013 - IPC G06K9/46 

FIELD: information technologies.

SUBSTANCE: method for localisation of road signs and recognition of their groups and subgroups in video frames of images consists in identification of areas of signs location by means of viewing of lines and columns of the image in a sliding window, if orders of colour alternation in the window match the reference one, the appropriate lines and columns are memorised, and the area of image on their crossing is identified as suspicious for location of a sign in it, in which they further identify an area limited with a red border of the sign, and in it, using lines and columns, they build two colour-independent histograms of all counts, which are normed in such a way that their ranges and the number of counts match with the appropriate characteristics of reference histograms, then using the normalised histograms they form a common histogram, and a corresponding vector, which is compared to vectors of references in the specified groups of signs, the decision on whether the current sign belongs to one of the groups of signs is taken on the basis of the criterion of the minimum measure of vector proximity, then in each group they define sign subgroups using histograms of black colour dots, which are formed and compared on the basis of the same rules as histograms used in detection of sign groups.

EFFECT: reduced time of localisation and increased reliability of road signs recognition.

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