Estimation of the gray level variations in soft and hard peri-implant tissue from X-ray images

摘要

In the treatment and assessment of periodontal disease periapical films are taken at regular intervals. The films are compared around the region of the implant to monitor the changes that have taken place. A computer-assisted method to automate this process is presented here. To compare two images, a pair of X-ray images are superimposed on top of each other. The images are normalized and transformed to obtain the best fit. These images are subtracted and the difference in pixel values are used as a basis for analysis. A method for improving the alignment accuracy and contrast compensation is highlighted.