In this paper we will show a way how to detect edges in digital images. Edge
detection is a fundamental part of many algorithms, both in image processing
and in video processing. Therefore it is important that the algorithm is
efficient and, if possible, fast to carry out. The fuzzy set theory based
approach on edge detection is good for use when we need to make some kind of
image segmentation, or when there is a need for edge classification (primary,
secondary, ...). One example that motivated us is region labeling; this is a
process by which the digital image is divided in units and each unit is given
a unique label (sky, house, grass, ?, etc.). To accomplish that, we need to
have an intelligent system that will precisely determine the edges of the
region. In this paper we will describe tools from image processing and fuzzy
logic that we use for edge detection as well as the proposed algorithm.