Initial images in terms of the present invention often have contents of medical import and are used in particular for diagnosing and in part also for purposes related to therapeutic treatment or, as the case may be, intervention. They are as a rule highly dynamic. The images in many cases furthermore contain fine details that include relevant image information, for example small vessels that are filled with a contrast medium, or guide wires. In many cases, such as while an intervention is in progress, the doctor providing the treatment is, however, unable or not well able to set imaging parameters and image editing parameters in such a way that the image will be edited well. The image presented should, though, also show all relevant details straight away, foremost in scene imaging, which is to say when there is a sequence of initial images.
In order to avoid excessive dynamism in the images presented, harmonizing is often carried out in the prior art using a predefined fixed filter core substantially corresponding to a high-pass filter. A major disadvantage of high-pass filters of said type is, however, the formation of black compression at edges, which can in extreme cases even lead doctors to make an incorrect diagnosis, but which as a rule at least result in an unfamiliar impression of an image.
The image's noise impression is also of significance for the observer. This applies foremost to X-ray-based imaging. That is because it will be very difficult to choose the correct contrast if the useful signal and noise cannot be separated from each other. If the contrast is too high, the observer's eye will be excessively irritated by the noise; if the contrast is too low, the signal will be almost or even completely undetectable.
It is known in the prior art how to proceed as follows for image editing:                A computer dismantles the initial image into partial images and a residual image.        Each partial image contains those components of the two-dimensional initial image that vary locally with a predetermined partial image frequency characteristic of the respective partial image and departing from zero.        The residual image contains at least one direct component of the two-dimensional initial image which component is locally invariable.        For each of the partial images and the residual image the computer determines a separate weighting factor with which it weights the respective partial image or, as the case may be, residual image, and sums the weighted partial images and weighted residual image into a final image.        
With this procedure it will, however, only be possible to produce a good final image if the weighting factors of the partial images and residual image have been suitably determined. Specifying suitable criteria for determining the weighting factors is the subject of the present invention.
USPTO Backgrounds
USPTO Backgrounds