| 摘要 |
A method for automatically identifying the range of useful digital values to be displayed on a display medium and providing an appropriate gray scale transfer to optimize the diagnostic value of the final displayed image. One or more gray scale transfer functions corresponding to desired display media, one or more sets of experimentally determined constants, and one or more sets of algorithms are stored in a computer memory. A smoothed histogram and its histogram integral are constructed representing the frequency of occurrence of the digital values stored in the data bank. A low point and an edge point are identified from the histogram and integral, and based on the type of radiographic examination selected, are used with appropriate constants and algorithms to calculate a maximum and minimum value. Values lower than the minimum are replaced with the minimum, and values higher than the maximum are replaced by the maximum. The new range of values are mapped using the appropriate gray scale transfer function to a set of values displayed on the display medium. |
