A degree of crowdedness in public pedestrian space is obtained from sequences of greyscale images and still colour images in order to provide a route selection hint to pedestrians. Two measures are employed: amount of motion and colour entropy, and they are used selectively depending on the nature of target space. The pedestrian space is categorised into two: smooth and stagnated. The smooth space urges pedestrians to flow smoothly without pausing, while the stagnated space invites pedestrians to pause for socialising. A degree of stagnation, obtained from accumulated differentiated images, is used to distinguish these two types of space. The amount of motion and the colour entropy are compared against human's sense of crowdedness for evaluation. The experiments have shown that the amount of motion represents the smooth space's crowdedness well, while the colour entropy is suitable for evaluating the stagnated space. It has also shown tendency of significance between the degree of stagnation and the types of space.