received by the International Bureau on 17 June 2014 (17.06.2014)

1. An x-ray system comprising:

an x-ray source; an image detector; a monitor; at least one input device configured to provide coordinates relative to an x-ray image displayed on said monitor; a first controller connected with said at least one input device, said first controller configured to determine at least one Region of Interest (ROI) on said displayed image; an image processing unit connected with said detector, said monitor and said first controller, said image processing unit configured to process the detected image displayed on said monitor by modifying image parts outside said at least one ROI according to the image part in said at least one ROI; and a second controller connected with said x-ray source, said second controller configured to control operating parameters of said x-ray source.

2. The x-ray system of claim 1 , wherein said image processing comprises determining a tone reproduction function for the image.

3. The x-ray system of claim 2, wherein said tone reproduction function is

implemented as one of brightness function, a contrast function, a gamma function, an offset function, an n-degree linear function and a non-linear function.

4. The x-ray system of claim , wherein said second controller is further connected with said first controller.

5. The x-ray system of claim 4, wherein said image processing comprises controlling said x-ray source parameters.

6. The x-ray system of claim 5, wherein said x-ray source parameters are selected from the group consisting of: current mode, Peak Kilo Voltage (PKV), pulse length and Automatic Gain Control (AGC).

7. The x-ray system of claim 1 , further comprising a collimator, said collimator

connected with said first controller and configured to modify the x-ray radiation dose per pixel (DPP) according a user's gazing coordinates.

8. A method of optimizing the display of an x-ray image captured from an x-ray source, comprising:

providing at least one input device configured to provide coordinates relative to an x- ray image displayed on said monitor; determining at least one Region of Interest (ROI) on said displayed image based on coordinates provided by said at least one input device; and processing the displayed image by modifying image parts outside said at least one ROI according to the image part in said at least one ROI.

9. The method of claim 8, wherein said image processing comprises determining a tone reproduction function for the image.

10. The method of claim 9, wherein said tone reproduction function is implemented as one of brightness function, a contrast function, a gamma function, an offset function, an n-degree linear function and a non-linear function.

11. The method of claim 8, wherein said image processing comprises controlling said x- ray source parameters.

12. The method of claim 1 , wherein said x-ray source parameters are selected from the group consisting of: current mode, Peak Kilo Voltage (PKV), pulse length and Automatic Gain Control (AGC).

13. An x-ray system comprising:

an x-ray source;

an image detector;

a monitor;

a controller; an image processing unit connected with said detector, said monitor and said controller; and a collimator connected with said controller, said collimator configured to expose a first area to a first radiation level and a second area to a second radiation level; said image processing unit further configured to process said second area to become similar to said first area using a tone-correction function.

14. The x-ray system of claim 13, wherein said tone-correction functions is one of at least two tone-correction functions, each of said at least two tone-correction functions associated with a specific PKV.

15. The x-ray system of claim 14, wherein said image processing unit is further

configured to create a tone -correct ion function by interpolation of two other tone- correction functions, each of the other tone-correction functions associated with a specific PKV.

16. The x-ray system of claim 13, wherein said image processing unit is further

configured to estimate a tone-correction function for a third area from the tone- correction function used for said second area.

17. The x-ray system of claim 16, wherein said estimation uses exponential calculation.

18. The x-ray system of claim 13, wherein said image processing unit is further

configured to adjust the input scale of the tone-correction function to fit changes in x-ray current.

19. The x-ray system of claim 18, wherein said adjustment is made using a factor equal to the relative change of the x-ray current.

20. A method of optimizing the display of an x-ray image captured from an x-ray source through a collimator configured to expose a first area to a first radiation level and a second area to a second radiation level, comprising:

processing said second area image to become similar to said first area image using a tone-correction function.

21. The method of claim 20, wherein said tone-correction functions is one of at least two tone-correction functions, each of said at least two tone-correction functions associated with a specific PKV.

22. The method of claim 21 , further comprising creating a tone-correction function by interpolation of two other tone-correction functions, each of the other tone-correction functions associated with a specific PKV.

23. The method of claim 20, further comprising estimating a tone-correction function for a third area from the tone-correction function used for said second area.

24. The method of claim 23, wherein said estimation uses exponential calculation.

25. The method of claim 20, further comprising adjusting the input scale of the tone- correction function to fit changes in x-ray current.

26. The method of claim 25, wherein said adjustment is made using a factor equal to the relative change of the x-ray current.

27. A system for calculating a tone-correction function for an x-ray exposure image comprising:

an x-ray source;

an image detector;

a controller;

an image processing unit connected with said detector and said controller; and

a variable absorption phantom, said controller configured to control said x-ray source so as to expose a first area to a first x-ray radiation and a second area to a second x-ray radiation, wherein at least a part of said first and second radiation is through said variable absorption phantom so that for each specific transmission level of said phantom there is at least one area exposed by said first radiation and at least one area exposed by said second radiation; said image processor configured: to calculate the average pixel value in said first area and the average pixel value in said second area for each specific transmission level; calculate the ratio of said two average pixel values for all designated absorption levels; and fit a function to said calculated ratios to be used as the tone-correction function.

28. The system of claim 27, wherein the variable absorption phantom is a step wedge.

29. The system of claim 27, wherein the variable absorption phantom is a variable thickness phantom of continuous slope function.

30. A method of calculating a tone-correction function for an x-ray exposure image comprising:

exposing a first area to a first x-ray radiation; exposing a second area to a second x-ray radiation, wherein at least a part of said first and second radiation is through a variable absorption phantom so that for each designated transmission level of said phantom there is at least one area exposed by said first radiation and at least one area exposed by said second radiation; for each such designated transmission level calculating the average pixel value in said first area and the average pixel value in said second area; calculating the ratio of said two average pixel values for all designated absorption levels; and fitting a function to said calculated ratios to be used as the tone-correction function.

31. The method of claim 30, wherein the variable absorption phantom is a step wedge.

32. The method of claim 30, wherein the variable absorption phantom is a variable thickness phantom of continuous slope function.

33. A system for calculating a tone-correction function for an x-ray exposure image comprising:

an x-ray source;

an image detector;

a controller; and an image processing unit connected with said detector and said controller, said controller configured to control said x-ray source so as to expose at least one area through human tissue to a first x-ray radiation and to expose said at least one area through human tissue to a second x-ray radiation, said image processor configured to calculate the ratio of at least one pixel value in said at least one area corresponding to said first radiation to the corresponding pixel value in said area corresponding to said second radiation and to fit a function to said at least one calculated ratio and pixel value in said at least one area

corresponding to said second radiation to be used as a first tone-correction function.

34. The system of claim 33, wherein a second tone-correction function is calculated, using data acquired after the acquisition of the data used to calculate said first tone- correction function.

35. The system of claim 33, wherein the data used to calculate said first tone-correction function is from at least two patients.

36. A method of calculating a tone-correction function for an x-ray exposure image

comprising:

exposing at least one area through human tissue to a first x-ray radiation;

exposing said at least one area through human tissue to a second x-ray radiation, calculating the ratio of at least one pixel value in said at least one area

corresponding to said first radiation to the corresponding pixel value in said area corresponding to said second radiation; and fitting a function to said at least one calculated ratio and pixel value in said at least one area corresponding to said second radiation to be used as a first tone- correction function.

37. The method of claim 36, wherein a second tone-correction function is calculated, using data acquired after the acquisition of the data used to calculate said first tone- correction function.

38. The method of claim 36, wherein the data used to calculate said first tone-correction function is from at least two patients.

39. An x-ray system comprising:

an x-ray source;

a collimator;

an image detector;

a monitor;

a controller;

an image processing unit connected with said detector, said monitor and said controller; and

means for moving said collimator in a plane generally parallel to the plane of said collimator; said collimator comprising: an aperture that allows all the radiation to pass through; an outer annulus that reduces the radiation passing through at an amount depending on the material and the thickness of the said outer annulus; and an inner annulus between said aperture and said outer annulus, with thickness changing as a function of the distance from said aperture, starting at a low thickness on the side of the aperture and ending at the thickness of the outer annulus on the side of the outer annulus; said image processing means configured to modify image data so as to essentially adjust the image acquired through the inner annulus and the image acquired through the outer annulus to appear visually similar to the image acquired through said aperture, wherein parameters used for said adjustments depend on the position of said collimator.

40. The system of claim 39, wherein said image processing unit is configured to acquire said parameters by a calibration procedure, said calibration procedure includes measurements made at a variety of said collimator positions.

41. The system of claim 40, wherein said variety of collimator positions comprise a variety of positions in the collimator plane.

42. The system of claim 40 wherein said variety of collimator positions comprise a

variety of distances from the x-ray source.

43. The system of claim 39 wherein said inner annulus thickness is essentially

symmetrical relative to a plane that is located essentially midway between the two external surfaces of said outer annulus.

44. The system of claim 39, further comprising a layer of material that is different from said material of the outer annulus, said layer located at said aperture area.

45. The system of claim 44 wherein said layer overlaps at least a part of said inner annulus.

46. A method of optimizing the display of an x-ray image captured from an x-ray source through a collimator comprising an aperture that allows all the radiation to pass through; an outer annulus that reduces the radiation passing through at an amount depending on the material and the thickness of the said outer annulus; and an inner annulus between said aperture and said outer annulus, with thickness changing as a function of the distance from said aperture, starting at a low thickness on the side of the aperture and ending at the thickness of the outer annulus on the side of the outer annulus, comprising:

adjusting the image acquired through the inner annulus and the image acquired through the outer annulus to appear visually similar to the image acquired through said aperture, wherein parameters used for said adjustments depend on the position of said collimator.

47. The method of claim 46, further comprising acquiring said parameters by a

calibration procedure, said calibration procedure includes measurements made at a variety of said collimator positions.

48. The method of claim 47, wherein said variety of collimator positions comprise a variety of positions in the collimator plane.

49. The method of claim 47 wherein said variety of collimator positions comprise a

variety of distances from the x-ray source.

50. The method of claim 46 wherein said inner annulus thickness is essentially symmetrical relative to a plane that is located essentially midway between the two external surfaces of said outer annulus.

51.

52.

53.

54.

55.

56. A system for enhancing an x-ray image displayed on a monitor comprising:

at least one input device configured to provide coordinates relative to an x-ray image displayed on said monitor; a controller connected with said at least one input device, said controller configured to determine at least one Region of Interest (ROI) on said displayed image; an image processing unit connected with said controller and with said monitor, said image processing unit configured to process the image displayed on said monitor by modifying image parts outside said at least one ROI according to the image part in said at least one ROI.

57. The system of claim 56, wherein said image processing comprises determining a tone reproduction function for the image.

58. The system of claim 57, wherein said tone reproduction function is implemented as one of brightness function, a contrast function, a gamma function, an offset function, an n-degree linear function and a non-linear function.

59.

60.

61. A collimator comprising:

an aperture that allows radiation to pass through;

an outer annulus that reduces the radiation passing through at an amount depending on the material and the thickness of the said outer annulus; and an inner annulus between said aperture and said outer annulus, with thickness changing as a function of the distance from said aperture, starting at a low thickness on the side of the aperture and ending at the thickness of the outer annulus on the side of the outer annulus.

62. The collimator of claim 61 , wherein said inner annulus thickness is essentially symmetrical relative to a plane that is located essentially midway between the two external surfaces of said outer annulus.

63. The collimator of claim 61 , further comprising a layer of material that is different from said material of the outer annulus, said layer located at said aperture area.

64. The collimator of claim 63 wherein said layer overlaps at least a part of said inner annulus.

65. The system of claim 1 , wherein said at least one input device is selected from the group consisting of: joy-stick, keyboard, interactive display, gesture reading device and voice interpreter.

66. The method of claim 8, wherein said at least one input device is selected from the group consisting of: joy-stick, keyboard, interactive display, gesture reading device and voice interpreter.

67. The system of claim 56, wherein said at least one input device is selected from the group consisting of: joy-stick, keyboard, interactive display, gesture reading device and voice interpreter.