Automatic scanning software based on the characteristic curve of mammogram digitizers

摘要

Mammogram acquisition in digital format is one of the most relevant steps for image processing in computer-aided detection schemes for mammography. We investigate film digitizer systems using different technologies to determine their influence on the results of mammography image segmentation schemes. It also provides image scanning process regardless of the technology by the development of automatic software based on the digitizers' characteristic curves. Comparative assessment of digitizer properties and features is performed as well as the software for managing the digitized image acquisition. The images were obtained from six different digitizers and evaluated by means of statistical analysis. Tests were conducted for comparing the responses from each equipment, regarding their respective curves, and they have presented significant variations relative to the original characteristic curve of high quality films used as reference-which largely influence the performance of processing schemes applied on sets of mammography images digitized by those systems. However, when our proposed scanning software was applied with intensity transformation procedure based on the characteristic curve "correction," the images were comparable to the film optical density, which has improved the processing technique's performance. The results have pointed out it is possible to achieve high sensitivity and performance of such schemes even with low-cost digitizer systems since their quality characteristics are well known and the procedure herein proposed is used within the mammogram scanning process.