Various approaches have been made for dividing images in content-based image retrieval. One of them defined five regions for images and conducted a series of experiments. A major assumption of the experiment is that the center regions of images are very important. It is based on the observation that meaningful objects are usually located in the center region of images. From this point of view, we tried to test if the assumptions is objectively valid by calculating and comparing PIM(Picture Information Measure) entropies of image regions proposed by S.K Chang. The experimental results showed that there were statistical PIM differences between the center and other regions.