Image Recognition System For Common Protozoan And Metazoan In Activated Sludge

In recent years, with the development of the digital image processing, applications of digital image processing technology have been received satisfactory results. According to historical records, content-based image retrieval system has been invented and chromosome images can be classified and so on.In this paper, we introduce an image recognition system for common protozoan and metazoan in activated sludge. For a picture containing protozoan, metazoan and impurities, first of all we have to extract the main body of the protozoan and metazoan, in this paper, we introduced two extraction methods——automatic target extraction method and interactive target extraction method, interactive target extraction methods is after we enter a digital image, we need to use the mouse to identify the target and background, while we do not need to do it in automatic target extraction method. Then, feature extraction, in this paper, we extracted a total of 16 kinds of features according to the following three aspects:(1)Morphological characteristics, including area, perimeter, etc, from these features we can determine the approximate shape of the protozoan and metazoan. For example, round or rectangular, and so on. (2)Texture features, including contrast, second moment, etc, from these features, we can get the protozoan and metazoans'surface structure arrangement information and their links with the surrounding environment. (3)Other characteristics, including whether it has the tail, and its uniformity, etc. From these characteristics, we can know whether the protozoan and metazoan has the tail and its uniform situation. Finally, with the extracted features, we use Decision Tree approach to classification. Decision Tree algorithm is to focus on defining a measure to each node of the tree. For example, when we determine whether the protozoan and metazoan'shape close to rectangular, we can use an external rectangular area divided by its own area of its own, and if this value is close to 1 indicates that it is close to rectangular. Detail steps will be described in the following article. Using the above methods, this paper focused on several common protozoan and metazoan in activated sludge, including paramecium, rotifer and nematode and so on, conducted effectively identify.