Lung cancer is the leading cancer among both men and women. Detection of lung cancer is important inorder to improve the survival rate. Presence of lung cancer can be diagnosed with the help of a CT image of the lung. The proposed system is used to detect the lung cancer in three steps. The steps include preprocessing stage, feature extraction stage and lung cancer cell identification stage. First step is capturing the input image. Second step is preprocessing. Preprocessing includes two processes such as image enhancement and image segmentation. The Weibull segmentation is used to describe the texture contrast, shape, scale and texture. The output from the image segmentation goes to the feature extraction stage. These extracted features are used to identify the abnormalities in the lung.