This paper describes the application of digital image processing and patter
n recognition techniques to assist in diagnosing neurological disorders. In
medical practices the posture and movement of a human subject through his/
her gait cycle contains information that is used by an experienced clinicia
n to determine the mental health of a patient. An image processing based sy
stem can be used to automate this process and produce quantified results. T
his is achieved by processing, extracting and classifying joint angle infor
mation from still images of a human subject's gait. Several new algorithms
are devised to process and extract the required information from the images
: a new edge extraction technique is used to assist in image segmentation;
a technique based on correlating images from different parts of a gait is u
sed to obtain complete information about a subject's posture; and an algori
thm based on the Hough Transform is used to obtain the limb joint angles an
d swing distances of a subject. Joint angles and swing distances obtained f
rom normal and patient subjects are then used in training and verifying cla
ssifications using a feed-forward neural network and a fuzzy clustering alg
orithm. (C) 1999 Academic Press.