Method of displaying on a viewing screen the output signals from a detector sensitive to radiation

Claim 2

In displaying on a viewing screen a varying image generated by video signals converted from output signals from a radiation detector, the method of enhancing the contrast of weakly contrasting details in the image when the radiation picked up by the detector covers a large intensity range comprising the steps of periodically measuring values of the output signals, statistically calculating two statistical parameter characteristics of the statistical properties of the thusly measured values, and adaptively regulating the amplification of video signals in parts of the video frequency spectrum which are below a given frequency value as a function the two statistically calculated statistical parameters.

Claim 3

The method of claim 1 wherein said regulating includes setting upper and lower amplification limiting values in accordance with said two statistical parameters.

Claim 4

The method of claim 2 wherein said measuring step comprises converting the output signals to sets of digital values.

Claim 5

The method of claim 3 wherein said statistically calculating step comprises determining the upper and lower percentile value for said sets of digital values and changing said amplification limiting values when the statistical distribution in a set of digital values changes.

Claim 6

In displaying on a view screen a varying image generated by video signals converted from output digital values derived by processing input digital values converted from signals emitted by a radiation detector, the method of processing said input digital values to said output signal values so that the contrast is enhanced for weakly contrasting details in the image when the radiation picked up by the radiation detector covers a large intensity range comprising: (a) low pass filtering the input digital values; (b) counting the number of filtered input digital values on either side of a limit corresponding to a selected point in the distribution curve of filtered input digital values; (c) adjusting the limit until the number of filtered input digital values falling on either side thereof correspond to said selected point; (d) repeating the counting and adjusting for a second limit corresponding to a second selected point in said distribution curve; and (e) adjusting the magnitude of said filtered input digital values to form at least part of said output digital values.

Claim 7

In displaying on a view screen a varying image generated by video signals converted from output digital values derived by processing input digital values converted from signals emitted by a radiation detector, the method of processing said input digital values to said output signal values so that the contrast is enhanced for weakly contrasting details in the image when the radiation picked up by the radiation detector covers a large intensity range comprising: (a) low pass filtering the input digital values; (b) counting the number of filtered input digital values on either side of a limit corresponding to a selected point in the distribution curve of filtered input digital values; (c) adjusting the limit until the number of filtered input digital values falling on either side thereof correspond to said selected point; (d) repeating the counting and adjusting for a second limit corresponding to a second selected point in said distribution curve; and (e) adjusting the magnitude of said filtered input digital values to form at least part of said output digital values.

Claim 8

The method of claim 4 further comprises subtracting the magnitude adjusted filtered input digital values from said input digital values to form said output digital values.