Image data correction processing

• US 20030179302A1
• Filed: 02/20/2003
• Published: 09/25/2003
• Est. Priority Date: 02/20/2002
• Status: Active Grant

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Harada, Osamu, Sakamoto, Hiromichi
• Granted Patent: US 7,317,481 B2
• Time in Patent Office: Days
• US Class Current: 348/231.6
• CPC Class Codes: H04N 25/63 applied to dark current
• CPC Class Codes: H04N 5/765 Interface circuits between an apparatus for recording and another apparatus
• CPC Class Codes: H04N 5/772 the recording apparatus and the television camera being placed in the same enclosure
• CPC Class Codes: H04N 5/907 using static stores, e.g. storage tubes or semiconductor memories H04N5/91 takes precedence
• CPC Class Codes: H04N 9/8047 using transform coding

Abstract

A signal processing device includes a memory which stores correction data in advance. The signal processing device modifies the correction data stored in the memory on the basis of an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state. The signal processing device corrects by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state.

Claims

1. An apparatus comprising:

(A) a memory adapted to store correction data;

(B) a signal processing device adapted to modify the correction data stored in said memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and adapted to correct by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state.

2. The apparatus according to claim 1, wherein said memory stores, as the correction data, reference correction data corresponding to part of an image sensing region of the image sensing unit.

3. The apparatus according to claim 2, wherein said signal processing device corrects an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in the exposure state, by using correction data so mapped as to make the reference correction data cope with the entire image sensing region of the image sensing unit.

4. The apparatus according to claim 1, wherein said memory stores, as the correction data, one-dimensional reference correction data corresponding to part of an image sensing region of the image sensing unit.

5. The apparatus according to claim 4, wherein the one-dimensional reference correction data includes data corresponding to a horizontal image sensing region of the image sensing unit.

6. The apparatus according to claim 1, wherein said signal processing device modifies the correction data stored in said memory by using an image sensing signal which is obtained by causing the image sensing unit to perform image sensing operation in the non-exposure state and corresponds to part of an image sensing region of the image sensing unit.

7. The apparatus according to claim 1, wherein said memory stores, as the correction data, data for canceling noise of the image sensing signal obtained by causing the image sensing unit to perform image sensing operation.

8. The apparatus according to claim 1, wherein said memory stores, as the correction data, shading correction data for the image sensing signal obtained by causing the image sensing unit to perform image sensing operation.

9. The apparatus according to claim 1, wherein said memory stores, as the correction data, dark level correction data for the image sensing signal obtained by causing the image sensing unit to perform image sensing operation.

10. The apparatus according to claim 1, wherein said memory stores, as the correction data, data for canceling fixed pattern noise of the image sensing signal obtained by causing the image sensing unit to perform image sensing operation.

11. The apparatus according to claim 1, wherein said signal processing device modifies an offset amount for the correction data stored in said memory by using an image sensing signal which is obtained by causing the image sensing unit to perform image sensing operation in the non-exposure state and corresponds to part of an image sensing region of the image sensing unit.

12. The apparatus according to claim 1, wherein said signal processing device modifies a correction coefficient for the correction data stored in said memory by using an image sensing signal which is obtained by causing the image sensing unit to perform image sensing operation in the non-exposure state and corresponds to part of an image sensing region of the image sensing unit.

13. The apparatus according to claim 1, wherein said signal processing device modifies an offset amount and a correction coefficient for the correction data stored in said memory by using an image sensing signal which is obtained by causing the image sensing unit to perform image sensing operation in the non-exposure state and corresponds to part of an image sensing region of the image sensing unit.

14. The apparatus according to claim 1, wherein the apparatus includes an image sensing apparatus.

15. An apparatus comprising:

(A) a memory adapted to store shading correction data;

(B) a signal processing device adapted to modify the shading correction data stored in said memory in accordance with an image sensing condition and correct an image sensing signal by using the modified shading correction data.

16. The apparatus according to claim 15, further comprising an image sensing unit adapted to receive an image of an object to be sensed and convert the image into the image sensing signal.

17. The apparatus according to claim 15, wherein the image sensing condition includes an image sensing sensitivity.

18. The apparatus according to claim 15, wherein said memory stores, as the shading correction data, one-dimensional reference shading correction data corresponding to part of an image sensing region of an image sensing unit.

19. The apparatus according to claim 18, wherein the one-dimensional reference shading correction data includes data corresponding to a horizontal image sensing region of said image sensing unit.

20. The apparatus according to claim 18, wherein the one-dimensional reference shading correction data includes data corresponding to a vertical image sensing region of said image sensing unit.

21. The apparatus according to claim 15, wherein when the image sensing condition is a predetermined image sensing condition, said signal processing device corrects the image sensing signal by using not the shading correction data stored in said memory but image sensing data obtained by causing an image sensing unit to perform image sensing operation in the non-exposure state.

22. The apparatus according to claim 21, wherein, in a sequential image sensing mode, said signal processing device causes said image sensing unit to perform image sensing operation in the non-exposure stage before image sensing, thereby obtaining the image sensing data, and in a single-shot image sensing mode, causes said image sensing unit to perform image sensing operation in the non-exposure state after image sensing, thereby obtaining the image sensing data.

23. The apparatus according to claim 15, wherein the apparatus includes an image sensing apparatus.

24. An image processing method comprising modifying correction data stored in a memory by using an image sensing signal obtained by causing an image sensing unit to perform image sensing operation in a non-exposure state, and correcting by using the modified correction data an image sensing signal obtained by causing the image sensing unit to perform image sensing operation in an exposure state.

25. A computer program for executing an image processing method defined in claim 24.

26. A medium which stores the computer program defined in claim 25.

27. An image processing method comprising modifying shading correction data stored in a memory in accordance with an image sensing condition, and correcting an image sensing signal by using the modified shading correction data.

28. A computer program for executing an image processing method defined in claim 27.

29. A medium which stores the computer program defined in claim 28.