Image signal correction device

• US 6,611,290 B1
• Filed: 03/26/1998
• Issued: 08/26/2003
• Est. Priority Date: 03/27/1997
• Status: Expired due to Fees

• Current Assignee: Pentax Corporation (Hoya Corporation)
• Original Assignee: Pentax Corporation (Hoya Corporation)
• Inventors: Sato, Koichi
• Primary Examiner(s): Garber, Wendy R.
• Assistant Examiner(s): Ye, Lin
• Application Number:
  US09/048,104
• Time in Patent Office: 1,979 Days
• Field of Search: 348/254, 348/256, 348/241, 348/242, 348/671, 348/674, 348/675, 348/604, 348/904, 348/333.01, 348/441, 348/445, 386/130, 345/10, 345/212, 382/154
• US Class Current: 348/333.01
• CPC Class Codes: H04N 1/407 Control or modification of tonal gradation or of extreme levels, e.g. background level
• CPC Class Codes: H04N 5/202 Gamma control circuits for controlling camera response irrespective of the scene brightness H04N23/82

Abstract

An image signal correction device, provided in an electronic still camera, comprises a CPU, an image signal processing circuit, a gamma look-up table and a display in which a recognition information storing unit is provided. A clock pulse, outputted from the CPU, is received by the recognition information storing unit, so that a recognition pulse, corresponding to the gamma characteristics of the display, is outputted from the recognition information storing unit to the CPU, enabling gamma look-up data to be inputted to the gamma look-up table. The image signal, outputted from the image signal processing circuit, is subjected to a gamma correction in the gamma look-up table, and outputted to the display.

Claims

1. An image signal correction device by which indication characteristics of a display negligibly affect an image, which is indicated by said display, said device comprising:

a recognition information storage in which recognition information indicating a type of display is stored, said recognition information storage being provided in said display; and

a correction processor that receives a recognition signal corresponding to said recognition information to recognize said indication characteristics, so that said correction processor makes a correction to said image signal in accordance with said indication characteristics, based on said recognition information, whereby a corrected image signal is outputted to said display, said correction processor being provided in an electronic device to which said display is connected.

2. An image signal correction device according to claim 1, wherein said electronic device is an electronic still camera.

3. An image signal correction device according to claim 1, further comprising a clock pulse generator that outputs a clock pulse of a constant period, said recognition information storage outputting said recognition signal in association with said clock pulse.

4. An image signal correction device according to claim 1, wherein said correction processor comprises a look-up table in which look-up data corresponding to said indication characteristics are stored, said look-up data being overwritable by said correction processor in accordance with said recognition information.

5. An image signal correction device according to claim 1, wherein said indication characteristics includes a gamma characteristic, and said correction processor makes a gamma correction to said image signal in accordance with said gamma characteristic.

6. The image signal correction device according to claim 1, said recognition information storage outputting a recognition pulse, spacing of said recognition pulse indicating a display type.

7. An image signal processing system comprising:

a display that has a recognition information storage in which recognition information indicating a type of said display is stored; and

an image signal corrector that has correcting information, selected in accordance with said recognition information, to perform an image correction corresponding to said recognition information, said image signal corrector being provided in an electronic device to which said display is connected.

8. The image signal correction device according to claim 7, wherein said electronic device is an electronic still camera.

9. The image signal correction device according to claim 7, wherein said recognition information storage outputs a recognition signal corresponding to said recognition information, so that said image signal corrector can recognize said recognition information.

10. The image signal correction device according to claim 9, further comprising a clock pulse generator that outputs a clock pulse of a constant period, said recognition information storage outputting said recognition signal in association with said clock pulse.

11. The image signal correction device according to claim 7, wherein said image signal correction device comprises a look-up table in which look-up data corresponding to said recognition information is stored, said look-up data being overwritable by said image signal corrector in accordance with said recognition information.

12. The image signal correction device according to claim 7, wherein said image signal corrector makes a gamma correction to an image signal in accordance with said recognition information.

13. The image signal correction device according to claim 7, said recognition information storage outputting a recognition pulse, spacing of said recognition pulse indicating a display type.

14. An image signal correction device connected to a display that has a recognition information storage, in which recognition information, corresponding to indication characteristics of the display is stored, said image signal correction device comprising:

a memory that stores correcting information, which is selected in accordance with said recognition information, that indicates a type of display so that an image correction corresponding to said indication characteristics is performed.

15. The image signal correction device according to claim 14, wherein said memory is provided in an electronic still camera.

16. The image signal correction device according to claim 14, wherein the recognition information storage outputs a recognition signal corresponding to the recognition information, so that the image signal correction device can recognize said indication characteristics.

17. The image signal correction device according to claim 16, further comprising a clock pulse generator that outputs a clock pulse of a constant period, the recognition information storage outputting said recognition signal in association with said clock pulse.

18. The image signal correction device according to claim 14, wherein said memory comprises a look-up table in which look-up data corresponding to said indication characteristics are stored, said look-up data being overwritable by said image signal correction device in accordance with said recognition information.

19. The image signal correction device according to claim 14, wherein said indication characteristics includes a gamma characteristic, and said image signal correction device makes a gamma correction to said image signal in accordance with said gamma characteristic.

20. The image signal correction device according to claim 14, said recognition information storage outputting a recognition pulse, spacing of said recognition pulse indicating a display type.

21. An image signal correction device by which indication characteristics of a display negligibly affect an image, which is indicated by said display, said device comprising:

a correction information storage in which correction information corresponding to indication characteristics of the display is stored, said correction information storage being provided in the display; and

a correction processor that receives said correction information to generate a correction table based on said correction information, so that an image signal is subjected to an image correction in accordance with said correction table, whereby a corrected image signal is outputted to the display, said correction processor being provided in an electronic device to which the display is connected.

22. An image signal correction device according to claim 21, wherein said electronic device is an electronic still camera.

23. An image signal correction device according to claim 21, wherein said image correction comprises a gamma correction.

24. The image signal correction device according to claim 21, said correction processor determining a type of display based upon said correction information, and adjusting an image on the display in accordance with the determined type of display.

25. An image signal processing system comprising:

a display that has a correction information storage in which correction information corresponding to indication characteristics of said display is stored; and

an image signal corrector that performs an image correction in accordance with correction information, said image signal corrector being provided in an electronic device to which said display is connected.

26. An image signal correction device according to claim 25, wherein said electronic device is an electronic still camera.

27. An image signal correction device according to claim 25, wherein said image correction comprises a gamma correction.

28. The image signal correction device according to claim 25, said image signal corrector determining a type of display based upon said correction information and adjusting an image on the display in accordance with the determined type of display.

29. An image signal correction device connected to a display that has a correction information storage, in which correction information corresponding to indication characteristics of the display is stored, said image signal correction device comprising:

a memory that stores a correction table that is generated in accordance with said correction information, an image correction corresponding to said indication characteristics being performed in accordance with said correction table.

30. An image signal correction device according to claim 29, wherein said memory is provided in an electronic still camera.

31. The image signal correction device according to claim 29, wherein said image correction comprises a gamma correction.

32. The image signal correction device according to claim 29, said device further determining a type of display based upon said correction information and adjusting an image on the display in accordance with the determined type of display.