IMAGE PROCESSING APPARATUS AND METHOD

• US 20020012450A1
• Filed: 01/08/1999
• Published: 01/31/2002
• Est. Priority Date: 01/09/1998
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: TSUJII, OSAMU
• Granted Patent: US 6,731,783 B2
• Time in Patent Office: Days
• US Class Current: 382/103
• CPC Class Codes: H04N 23/30 for generating image signals from X-rays
• CPC Class Codes: H04N 5/32 Transforming X-rays cameras or camera modules for generating image signals from X-rays H04N23/30; circuitry of SSIS for transforming X-rays into image signals H04N25/30
• CPC Class Codes: H05G 1/60 Circuit arrangements for obtaining a series of X-ray photographs or for X-ray cinematography

Abstract

An X-ray beam transmitted through an object is transmitted through a grid, which has been moved to the X-ray irradiation position, and reaches a panel sensor after scattered X-rays are removed by the grid. Image processing is done on the basis of a reduced image input from the panel sensor. As the reduced image, an image reduced to ⅛ the image output from the panel sensor in both the vertical and horizontal directions is used, and the image is binarized by a predetermined threshold value. Noise of the binary image is removed by an opening filter, and lines of the noise-removed image are scanned in the x- and y-directions to form a list of scan start and end points. The average values of these points are calculated to determine an irradiated region. By extracting an image of the irradiated region from the panel sensor, fluoroscopic image observation and still image photographing are efficiently done using a panel sensor with a large photographing frame.

Claims

1. An image processing apparatus comprising:

a two-dimensional sensor for converting a radiation image on a two-dimensional irradiated plane formed by a radiation source into an electric image signal;

detection means for detecting a range of the two-dimensional irradiated plane on said two-dimensional sensor; and

display means for acquiring and displaying image data within the range detected by said detection means from said two-dimensional sensor.

2. The apparatus according to claim 1, wherein said detection means detects the irradiated range on the basis of image data obtained from said two-dimensional sensor.

3. The apparatus according to claim 1, wherein said detection means reduces an image obtained from said two-dimensional sensor, and detects the range of the two-dimensional irradiated plane from the reduced image.

4. The apparatus according to claim 1, wherein said display means has enlargement/reduction-means for enlarging/reducing image data within the detected range in correspondence with a display size on a display device.

5. The apparatus according to claim 1, further comprising:

radiation source moving means for moving the two-dimensional irradiated plane on said two-dimensional sensor by moving said radiation source at least in one dimensional direction in a space.

6. The apparatus according to claim 5, further comprising:

a grid for removing scattered rays coming from an object placed between said radiation source and said two-dimensional sensor; and

grid moving means for moving a position of said grid to track movement of the irradiated range upon movement of the two-dimensional irradiated plane.

7. The apparatus according to claim 5, further comprising:

a phototimer for integrating a dose of the radiation; and

phototimer moving means for moving a position of said phototimer to track movement of the irradiated range upon movement of the two-dimensional irradiated plane at a position between an object that absorbs the radiation and said two-dimensional sensor or on a back surface of said two-dimensional sensor.

8. The apparatus according to claim 7, further comprising:

pattern forming means for forming an approximate pattern of said phototimer on the basis of data input in advance; and

superimposing means for superimposing the approximate pattern of said phototimer into the irradiated range on the basis of the phototimer position moved by said phototimer moving means and the irradiated range.

9. The apparatus according to claim 6, further comprising:

a phototimer fixed to said grid; and

superimposing means for superimposing an approximate pattern of said phototimer on an image within an irradiated range detected by said detection means on the basis of a position of said grid moved by said grid moving means, and the irradiated range.

10. The apparatus according to claim 1, further comprising:

changing means for changing a gain of a signal amplifier for said two-dimensional sensor on the basis of a photographing mode designated by an operator.

11. The apparatus according to claim 1, further comprising:

a camera for photographing a visible light image including the irradiated range;

calculation means for calculating a physical size of the visible light image on the basis of a sensor size, focus distance, and focal length of said camera; and

superimposing means for adjusting a size of an image in the irradiated range on the basis of the calculated physical size, and superimposing the image in the irradiated range on the visible light image.

12. The apparatus according to claim 11, wherein said camera has auto-focus and zoom functions.

13. The apparatus according to claim 11, wherein said camera is attached to said radiation source via elevation angle control means for controlling an elevation angle of said camera, and said elevation angle control means controls the elevation angle of said camera on the basis of a distance between said radiation source and said two-dimensional sensor.

14. The apparatus according to claim 1, further comprising:

parallel read-out means for dividing said two-dimensional sensors into a plurality of regions and parallelly reading out signals from the plurality of regions; and

sensor moving means for moving said two-dimensional sensor to divide the irradiated range detected by said detection means by the plurality of regions.

15. The apparatus according to claim 14, wherein said sensor moving means moves said two-dimensional sensor to locate the irradiated range substantially evenly on the plurality of regions.

16. The apparatus according to claim 14, further comprising:

radiation source moving means for moving, in a system in which a perpendicular dropped from said radiation source to said two-dimensional sensor is defined as a Z-axis, and X- and Y-axes perpendicular to the Z-axis are defined, said radiation source at least in the Y-axis direction, and

wherein the plurality of divided regions on said two-dimensional sensor are two regions divided in the Y-axis direction by a first dividing line, and

said sensor moving means obtains a second dividing line that divides the irradiated region in the Y-axis direction, and moves said two-dimensional sensor in the Y-axis direction to make the first and second dividing lines substantially overlap each other.

17. The apparatus according to claim 1, wherein said detection means and display means repeatedly operate by setting an execution frequency of said display means to be higher than an execution frequency of said detection means.

18. An image processing method comprising:

the conversion step of converting a radiation image on a two-dimensional irradiated plane formed by a radiation source into an electric image signal using a two-dimensional sensor;

the detection step of detecting a range of the two-dimensional irradiated plane on said two-dimensional sensor; and

the display step of acquiring and displaying image data within the range detected in the detection step from said two-dimensional sensor.

19. The method according to claim 18, wherein the detection step includes the step of detecting the irradiated range on the basis of image data obtained from the conversion step.

20. The method according to claim 18, wherein the detection step includes the step of reducing an image obtained from said two-dimensional sensor, and detecting the range of the two-dimensional irradiated plane from the reduced image.

21. The method according to claim 18, wherein the display step includes the enlargement/reduction step of enlarging/reducing image data within the detected range in correspondence with a display size on a display device.

22. The method according to claim 18, further comprising:

the radiation source moving step of moving the two-dimensional irradiated plane on said two-dimensional sensor by moving said radiation source at least in one dimensional direction in a space.

23. The method according to claim 22, further comprising:

the grid moving step of moving a position of a grid for removing scattered rays coming from an object placed between said radiation source and said two-dimensional sensor to track movement of the irradiated range upon movement of the two-dimensional irradiated plane.

24. The method according to claim 22, further comprising:

the phototimer moving step of moving a position of a phototimer for integrating a dose of the radiation to track movement of the irradiated range upon movement of the two-dimensional irradiated plane at a position between an object that absorbs the radiation and said two-dimensional sensor or on a back surface of said two-dimensional sensor.

25. The method according to claim 24, further comprising:

the pattern forming step of forming an approximate pattern of said phototimer on the basis of data input in advance; and

the superimposing step of superimposing the approximate pattern of said phototimer on the irradiated range on the basis of the phototimer position moved in the phototimer moving step and the irradiated range.

26. The method according to claim 23, further comprising:

the superimposing step of superimposing an approximate pattern of a phototimer fixed to said grid on an image within an irradiated range detected in the detection step on the basis of a position of said grid moved in the grid moving step, and the irradiated range.

27. The method according to claim 18, further comprising:

the changing step of changing a gain of a signal amplifier for said two-dimensional sensor on the basis of a photographing mode designated by an operator.

28. The method according to claim 18, further comprising:

the calculation step of calculating a physical size of a visible light image on the basis of a sensor size, focus distance, and focal length of a camera for photographing a visible light image including the irradiated range; and

the superimposing step of adjusting a size of an image in the irradiated range on the basis of the calculated physical size, and superimposing the image in the irradiated range on the visible light image.

29. The method according to claim 28, wherein said camera is attached to said radiation source via elevation angle control means for controlling an elevation angle of said camera, and

said method further comprises the elevation angle control step of controlling the elevation angle of said camera by said elevation angle control means on the basis of a distance between said radiation source and said two-dimensional sensor.

30. The method according to claim 18, further comprising:

the parallel read-out step of dividing said two-dimensional sensors into a plurality of regions and parallelly reading out signals from the plurality of regions; and

the sensor moving step of moving said two-dimensional sensor to divide the irradiated range detected in the detection step by the plurality of regions.

31. The method according to claim 30, wherein the sensor moving step includes the step of moving said two-dimensional sensor to locate the irradiated range substantially evenly on the plurality of regions.

32. The method according to claim 30, further comprising:

the radiation source moving step of moving, in a system in which a perpendicular dropped from said radiation source to said two-dimensional sensor is defined as a Z-axis, and X- and Y-axes perpendicular to the Z-axis are defined, said radiation source at least in the Y-axis direction, and

wherein the plurality of divided regions on said two-dimensional sensor are two regions divided in the Y-axis direction by a first dividing line, and

the sensor moving step includes the step of obtaining a second dividing line that divides the irradiated region in the Y-axis direction, and moving said two-dimensional sensor in the Y-axis direction to make the first and second dividing lines substantially overlap each other.

33. The method according to claim 18, wherein the detection step and display step repeatedly operate by setting an execution frequency of the display step to be higher than an execution frequency of the detection step.

34. An image processing apparatus having a two-dimensional sensor for receiving a radiation image by a two-dimensional detection surface and converting the radiation image into an electrical signal, wherein image data obtained by said two-dimensional sensor is displayed parallel to a visible image.

35. The apparatus according to claim 34, wherein an image input range of the radiation image in the two-dimensional detection surface is detected.

36. The apparatus according to claim 34, wherein the parallel display is implemented by inserting and displaying the image data obtained by said two-dimensional sensor into a radiation image photographing position in the visible image of an object to be photographed.

37. The apparatus according to claim 34, wherein the image data obtained from said two-dimensional sensor is a moving image.

38. An image processing method for an apparatus having a two-dimensional sensor for receiving a radiation image by a two-dimensional detection surface and converting the radiation image into an electrical signal, wherein image data obtained by said two-dimensional sensor is displayed parallel to a visible image.

39. The method according to claim 38, wherein an image input range of the radiation image in the two-dimensional detection surface is detected.

40. The method according to claim 38, wherein the parallel display is implemented by inserting and displaying the image data obtained by said two-dimensional sensor into a radiation image photographing position in the visible image of an object to be photographed.

41. The method according to claim 38, wherein the image data obtained from said two-dimensional sensor is a moving image.

42. A storage medium which stores a control program for making a computer execute image processing, said control program comprising:

a code of the conversion step of converting a radiation image on a two-dimensional irradiated plane formed by a radiation source into an electric image signal using a two-dimensional sensor;

a code of the detection step of detecting a range of the two-dimensional irradiated plane on said two-dimensional sensor; and

a code of the display step of acquiring and displaying image data within the range detected in the detection step from said two-dimensional sensor.