texture feature extraction for classification

I am extracting texture feature from mammogram image for classification. I am using matlab. I have extracted laws texture energy for mammogram image. I have used 5x5 mask, the output is 25 feature image . In some research article, the energy map for each feature image is given in numeric values . I am confused.... because I am getting it has an image. Example : energy measure for major region E5E5 45. What is actually calculated and how it is calculated?