Ключевые слова: black metal pole, cement sidewalk pollution, center street, center street scene, cigarette butts, city pollution, city streets, city streetscape, cityscape filter, cityscape pollution, concrete pavement, concrete sidewalk, discarded litter, discarded paper, discarded tissues, filthy pavement, pigeon droppings, pigeon pollution, pigeon problem, pigeon waste, pigeonrelated dirt, pigeonrelated message, sidewalk mess, sidewalk stains, street dirt, street litter, urban cleanliness, urban environment, urban filter, urban hygiene, walking person,