Adaptive x-ray brightness and display control for a medical imaging system
First Claim
1. An automatic brightness control for an x-ray imaging system having a source of x-rays, a detector having a video camera which produces an image signal formed by attenuated x-rays, and a video monitor which converts the image signal into a video image;
- the automatic brightness control comprising;
a peak detector receiving the image signal and producing a video gain signal in response to a comparison of a peak level of the image signal to a peak reference level, wherein the video gain signal is applied to control the video camera;
an average brightness detector receiving the image signal and producing an output signal which represents an average brightness level for the image signal and wherein the output signal is employed to control the source of x-rays;
a transfer function generator which receives the image signal and produces a set of values which defines an image transfer function; and
an image processor which receives the set of values from said transfer function generator and applies the image transfer function to the image signal.
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Abstract
An x-ray imaging system includes a source of x-rays, a video camera which produces an image signal formed by x-ray attenuation values, and image signal processor and a video monitor for displaying the x-ray image. The system also has an automatic image control that includes a peak detector, an average brightness detector and a transfer function generator for the image processor. The peak detector receives the image signal and produces a video gain control signal for controlling the video camera in response to a comparison of a peak level of the image signal to a peak reference level. The average the brightness detector employs the image signal to produce a feedback signal which controls by the source of x-rays. The transfer function generator produces a histogram of intensity levels in the image signal which histogram forms a look-up table that is used by the image processor to transform the image signal into the adjusted image signal for display.
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Citations
19 Claims
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1. An automatic brightness control for an x-ray imaging system having a source of x-rays, a detector having a video camera which produces an image signal formed by attenuated x-rays, and a video monitor which converts the image signal into a video image;
- the automatic brightness control comprising;
a peak detector receiving the image signal and producing a video gain signal in response to a comparison of a peak level of the image signal to a peak reference level, wherein the video gain signal is applied to control the video camera; an average brightness detector receiving the image signal and producing an output signal which represents an average brightness level for the image signal and wherein the output signal is employed to control the source of x-rays; a transfer function generator which receives the image signal and produces a set of values which defines an image transfer function; and an image processor which receives the set of values from said transfer function generator and applies the image transfer function to the image signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- the automatic brightness control comprising;
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10. An automatic brightness control for an x-ray imaging system having a source of x-rays, a detector having a video camera which produces an image signal formed by attenuated x-rays, and a video monitor which converts the image signal into a video image;
- the automatic brightness control comprising;
a transfer function generator coupled to the video camera for receiving the image signal and producing a set of values which define an image transfer function, said transfer function generator comprising a processor for deriving the image transfer function from a histogram of image intensity levels in the image signal; and an image processor which applies the image transfer function to the image signal to produce an adjusted image signal for display by the video monitor. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
- the automatic brightness control comprising;
Specification