A method for the visual analysis of streetscape character using digital image processing
Authors: Tucker, Chris ; Ostwald, Michael J.; Chalup, Stephan K.
ABSTRACT: This paper outlines an interdisciplinary approach, utilising architectural knowledge and
computer imaging, to develop an analytical tool that describes the visual characteristics of a
streetscape. By segmenting a digital image into regions defined by edges, the streetscape can be
studied as an arrangement of regions or elements with a particular relationship. Different parts of the
street (usually defined a by a single dwelling) can then be related to each other to find what
similarities, if any, exist at a purely visual level.
The concept of the use of streetscape character as a planning instrument is typically discussed in
terms of imageability and spatial configuration (Lynch 1960 & Hillier 1996). A method is developed in
the present paper that outlines the digital image processing techniques used to record dwellings within
a locality. The method utilises the Hough transform, an algorithm that provides a global measure of the
geometry within an image. This algorithm is conceptually related to visual partitioning within Gestalt
psychology as well as to the theory of description retrieval developed by Hillier. The process used to
define variables within the algorithm and the way in which images of a streetscape have been
collected are discussed. The method developed in this paper indicates that digital image processing
can differentiate the visual composition of elements within a streetscape. The method will form the
basis for future research concerning the visual characteristics of the built environment.