| Normally, the image quality evaluation is carried out by comparing the enhanced image with the reference image. However, there is no reference image during medical diagnosis. Therefore, the image quality evaluation of the medical image is checked by an expert. The purpose of this research is to clarify the difference of image features between an image that can be used for practical diagnosis and other images that can not be used for practical diagnosis. In the last conference, power spectrum was used as image feature to evaluate the image quality . In this paper, standard deviation is used to distinguish the best and worse images. |