| 摘要 |
The present invention provides a multi-threshold algorithm which is used to categorise areas of an image into a plurality of different categories. Each area or group of areas is then subjected to its own thresholding algorithm. The method provides for accurate identification of features of an image, such as edge features. By using a first thresholding algorithm a threshold applicable to each of a plurality of image areas is determined and image areas are classified based on these determined thresholds. For image areas which include a plurality of classification possibilities, a second thresholding step is performed within said area to determine a threshold related to an image parameter (e.g. intensity). The area may be divided into up to seven vertical areas as part of this second thresholding step. In order to visualise edges more clearly, the image may be presented as a three value image after the first thresholding step, for example, with different thresholds being subsequently applied within image areas including plural classifications to enhance edge visualisation. |
