The clouds in the infrared cloud image are composed of cumulonimbus, cirrus, stratus and cumulus which are useful to study the atmosphere. We can use the fractal dimension algorithm to segment the clouds according to the different fractal dimension of them. But the result of the segmentation can't be accurate when only fractal dimension is used, since the earth's surface has the similar fractal dimension with some clouds. To solve the question, we use Otsu algorithm to separate the interference of earth's s...