A method for segmenting the surface (5a,5b) of a tyre including at least one groove, said method comprising: - irradiating a portion of said surface (5a,5b) of said tyre with electromagnetic radiation having a wavelength in the visible spectrum; - acquiring an image of said portion of the irradiated surface; - processing said image so as to segment it into regions (101, 102) corresponding to regions of the tyre which do or do not belong to said at least one groove; - wherein the processing of said image so as to segment it includes: ∘ calculating a statistical quantity associated with the irradiation by said electromagnetic radiation for each region (101, 102) of said image; ∘ determining whether said region (101, 102) of said image does or does not belong to said at least one groove according to the value of said statistical quantity, characterised in that calculating said statistical quantity for each region (101, 102) of said image includes calculating a value of the dispersion of the data relative to a variable related to a light intensity of each region (101, 102) of the image of said portion of the irradiated surface (5a, 5b) acquired, and in that determining whether said region (101, 102) of said image does or does not belong to said groove further includes calculating the ratio between two values of said statistical quantity of two separate regions (101, 102), where one of the two regions belongs to said groove and the other does not belong to said groove when said ratio has a value outside a predetermined range. - irradiating a portion of said surface (5a,5b) of said tyre with electromagnetic radiation having a wavelength in the visible spectrum; - acquiring an image of said portion of the irradiated surface; - processing said image so as to segment it into regions (101, 102) corresponding to regions of the tyre which do or do not belong to said at least one groove; - wherein the processing of said image so as to segment it includes: ∘ calculating a statistical quantity associated with the irradiation by said electromagnetic radiation for each region (101, 102) of said image; ∘ determining whether said region (101, 102) of said image does or does not belong to said at least one groove according to the value of said statistical quantity, characterised in that calculating said statistical quantity for each region (101, 102) of said image includes calculating a value of the dispersion of the data relative to a variable related to a light intensity of each region (101, 102) of the image of said portion of the irradiated surface (5a, 5b) acquired, and in that determining whether said region (101, 102) of said image does or does not belong to said groove further includes calculating the ratio between two values of said statistical quantity of two separate regions (101, 102), where one of the two regions belongs to said groove and the other does not belong to said groove when said ratio has a value outside a predetermined range. ∘ calculating a statistical quantity associated with the irradiation by said electromagnetic radiation for each region (101, 102) of said image; ∘ determining whether said region (101, 102) of said image does or does not belong to said at least one groove according to the value of said statistical quantity,