The present disclosure provides an apparatus for detecting placards in a captured image, comprising: input circuitry operable to receive the captured image; detector circuitry operable to detect placards in the captured image on a basis of a predetermined shape and/or color of the placards, the detector circuitry being operable to detect placards of a plurality of different shapes and/or colors; and counter circuitry operable to count a number of detected placards of each different shape and/or color.