An apparatus and method for encoding and decoding an image are provided. The analysis results are aimed at the detection, classification and quantification of optically resolvable specimen such as micro-organisms or cells. The first conductor, the second conductor, and the third conductor are provided in a first conductive region, a second conductive region, and a third conductive region in the housing respectively, wherein the projection regions of the first conductive region and the second conductive region in the normal direction of the housing are overlapped.