In recent years along with the advance in technology, using the functions and quality of imaging devices is getting more and more common, how processes the image is quite important. But in examination work, if with human eye judgment graph slight defect, regular session, because artificial subjectively or creates the mistake wearily, therefore in the examination graph slight defect, needs the computer precess image compared and defect inspection. In this thesis , we concentrate in provide a graph compares to the method, use wavelet transform, may have ability to underline in view of the slight defect part. This thesis basis different energy sub-area makes gradually the level –like compared to rightly, may use the primitive image most important part first compared to right, is left over some pictures are enhancing the threshold to do severely compared to the way, like this gradually the level -like compared to the method, the far ratio two picture one by one pixel value makes compares to effectiveness.