Image sensing apparatus, image processing apparatus, and control method therefor

• US 20050013603A1
• Filed: 07/13/2004
• Published: 01/20/2005
• Est. Priority Date: 07/15/2003
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Ichimasa, Shoji
• Granted Patent: US 7,414,667 B2
• Time in Patent Office: Days
• US Class Current: 396/158
• CPC Class Codes: G06V 40/193 Preprocessing; Feature extraction
• CPC Class Codes: H04N 1/62 Retouching, i.e. modification of isolated colours only or in isolated picture areas only
• CPC Class Codes: H04N 1/624 Red-eye correction control of camera based on recognised facial parts H04N23/611

Abstract

This invention makes it possible to execute photography with a sufficient red-eye relaxation effect. To do this, in this invention, the amount of a red eye is detected on the basis of a signal obtained by reading an object image under light projection by a light projection unit. The light projection by the light projection unit is controlled on the basis of the detection result.

Claims

1. An image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a control unit which causes the red-eye relaxation light projection unit to execute a red-eye relaxation operation and, after the red-eye relaxation operation, causes the electronic flash unit to project light,

said control unit comprising

a red-eye determination unit which determines a red-eye size by executing preliminary image sensing during red-eye relaxation light projection by the red-eye relaxation light projection unit, and

a processing determination unit which determines, on the basis of a determination result by said red-eye determination unit, whether processing is to shift to image sensing with light projection by the electronic flash unit and whether red-eye relaxation by the red-eye relaxation light projection unit is to be continued.

2. The apparatus according to claim 1, characterized in that said processing determination unit sets, as a condition to continue red-eye relaxation, that the red-eye size exceeds a first threshold value, and the number of times of preliminary image sensing is not more than a predetermined number of times.

3. The apparatus according to claim 1, characterized in that when the red-eye size exceeds a first threshold value, and the number of times of preliminary image sensing is not more than a predetermined number of times, said processing determination unit invalidates a main image sensing instruction.

4. The apparatus according to claim 2, characterized in that said processing determination unit sets, as another condition to continue red-eye relaxation, that the red-eye size exceeds a second threshold value smaller than the first threshold value, the number of times of preliminary image sensing is not more than the predetermined number of times, and no main image sensing instruction is present.

5. The apparatus according to claim 4, characterized in that when the number of times of preliminary image sensing has reached the predetermined number of times, or when the red-eye size exceeds the second threshold value, and the main image sensing instruction is present, said processing determination unit determines that red-eye correction is to be executed and permits shift to image sensing with light emission by the electronic flash unit.

6. The apparatus according to claim 5, characterized in that when the red-eye size is not more than the second threshold value, said processing determination unit determines that red-eye correction is not to be executed and permits shift to image sensing with light emission by the electronic flash unit.

7. An image sensing apparatus comprising an image sensing unit, a light projection unit, an image acquisition unit which acquires sensed image data from the image sensing unit, and a display unit which displays the sensed image data acquired by the image acquisition unit, characterized by comprising:

a detection unit which detects a red-eye region in the sensed image data acquired by the image acquisition unit during light projection by the light projection unit,

wherein the display unit enlarges and displays the sensed image data in accordance with the red-eye region detected by said detection unit.

8. An image sensing apparatus comprising an image sensing unit, a light projection unit, and an image acquisition unit which acquires sensed image data from the image sensing unit, characterized by comprising:

a detection unit which detects a red-eye region in the sensed image data acquired by the image acquisition unit during light projection by the light projection unit, and

a control unit which controls an amount of light projected by the light projection unit in accordance with a size of the red-eye region detected by said detection unit.

9. The apparatus according to claim 8, characterized in that said control unit changes the amount of light projected by the light projection unit over time in accordance with the size of the red-eye region detected by said detection unit.

10. A control method for an image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a red-eye determination step of determining a position and size of a red eye by executing preliminary image sensing during red-eye relaxation light projection by the red-eye relaxation light projection unit; and

a processing determination step of determining, on the basis of a determination result in the red-eye determination step, whether processing is to shift to image sensing with light projection by the electronic flash unit.

11. A control method for an image sensing apparatus comprising an image sensing unit, a light projection unit, an image acquisition unit which acquires sensed image data from the image sensing unit, and a display unit which displays the sensed image data acquired by the image acquisition unit, characterized by comprising:

a detection step of detecting a red-eye region in the sensed image data acquired by the image acquisition unit during light projection by the light projection unit; and

a display step of causing the display unit to enlarge and display the sensed image data in accordance with the red-eye region detected in the detection step.

12. A control method for an image sensing apparatus comprising an image sensing unit, a light projection unit, and an image acquisition unit which acquires sensed image data from the image sensing unit, characterized by comprising:

a detection step of detecting a red-eye region in the sensed image data acquired by the image acquisition unit during light projection by the light projection unit; and

a control step of controlling an amount of light projected by the light projection unit in accordance with a size of the red-eye region detected in the detection step.

13. An image processing apparatus having an image sensing unit and a light projection unit, characterized by comprising:

a first image acquisition unit which causes the image sensing unit to acquire first sensed image data during light projection by the light projection unit;

a second image acquisition unit which causes the image sensing unit to acquire second sensed image data during light projection by the light projection unit a predetermined time after said first image acquisition unit acquires the first sensed image data;

a comparison unit which compares the first sensed image data with the second sensed image data, which are acquired by said first image acquisition unit and said second image acquisition unit, respectively; and

a detection unit which detects a position and size of a red eye on the basis of a comparison result by said comparison unit.

14. The apparatus according to claim 13, characterized in that said comparison unit subtracts data of a red component in the image data acquired by said second image acquisition unit from data of a red component in the image data acquired by said first image acquisition unit.

15. The apparatus according to claim 13, characterized by further comprising an image shift correction unit which corrects a shift amount of the second sensed image data with respect to the first sensed image data,

wherein said comparison unit compares the sensed images after image shift correction.

16. An image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a first control unit which causes the red-eye relaxation light projection unit to execute red-eye relaxation; and

a second control unit which executes image sensing by using the electronic flash unit after control by said first control unit,

said first control unit comprising

a storage/holding unit which causes the red-eye relaxation light projection unit to start projecting red-eye relaxation light, causes the image sensing unit to execute preliminary image sensing every predetermined time, and stores/holds latest first sensed image data and the second sensed image data the predetermined time before,

a comparison unit which compares the first sensed image data with the second sensed image data,

a red-eye determination unit which determines a position and size of a red eye on the basis of a comparison result by said comparison unit, and

a processing determination unit which determines, on the basis of a determination result by said red-eye determination unit, whether processing is to shift to said second control unit, and if shift is to be executed, whether red-eye correction is to be executed, and whether red-eye relaxation by the red-eye relaxation light projection unit is to be continued, and

said second control unit comprising

an image sensing unit which causes the image sensing unit to execute image sensing unit while causing the electronic flash unit to emit electronic flash light, and

a correction unit which corrects image data of a red component in a region corresponding to the position and size of the red eye determined by said red-eye determination unit when said processing determination unit determines that red-eye correction is to be executed.

17. The apparatus according to claim 16, characterized in that said comparison unit subtracts data of a red component in the first sensed image data from data of a red component in the second sensed image data.

18. The apparatus according to claim 16, characterized in that said processing determination unit sets, as a condition to continue red-eye relaxation, that the red-eye size exceeds a first threshold value, and the number of times of preliminary image sensing is not more than a predetermined number of times.

19. The apparatus according to claim 18, characterized in that when the red-eye size exceeds a first threshold value, and the number of times of preliminary image sensing is not more than a predetermined number of times, said processing determination unit invalidates a main image sensing instruction.

20. The apparatus according to claim 18, characterized in that said processing determination unit sets, as another condition to continue red-eye relaxation, that the red-eye size exceeds a second threshold value smaller than the first threshold value, the number of times of preliminary image sensing is not more than the predetermined number of times, and no main image sensing instruction is present.

21. The apparatus according to claim 20, characterized in that when the number of times of preliminary image sensing has reached the predetermined number of times, or when the red-eye size exceeds the second threshold value, and the main image sensing instruction is present, said processing determination unit determines that red-eye correction is to be executed and permits shift to said second control unit.

22. The apparatus according to claim 21, characterized in that when the red-eye size is not more than the second threshold value, said processing determination unit determines that red-eye correction is not to be executed and permits shift to said second control unit.

23. The apparatus according to claim 22, characterized by further comprising a notification unit which notifies a result of condition determination when it is determined that the shift to said second control unit is to be executed.

24. The apparatus according to claim 23, characterized in that said notification unit changes a display form of a mark in accordance with each condition for the shift to said second control unit.

25. An image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a first image acquisition unit which causes the image sensing unit to acquire first sensed image data during light projection by the electronic flash unit;

a second image acquisition unit which causes the image sensing unit to acquire second sensed image data during light projection by the light projection unit a predetermined time after said first image acquisition unit acquires the first sensed image data;

a comparison unit which compares the first sensed image data with the second sensed image data, which are acquired by said first image acquisition unit and said second image acquisition unit, respectively;

a detection unit which detects a position and size of a red eye on the basis of a comparison result by said comparison unit; and

a correction unit which corrects, of the first sensed image data, image data of a red component in a region corresponding to the position and size of the red eye detected by said detection unit.

26. The apparatus according to claim 25, characterized in that said comparison unit subtracts data of a red component in the image data acquired by said second image acquisition unit from data of a red component in the image data acquired by said first image acquisition unit.

27. A control method for an image processing apparatus having an image sensing unit and a light projection unit, characterized by comprising:

a first image acquisition step of causing the image sensing unit to acquire first sensed image data during light projection by the electronic flash unit;

a second image acquisition step of causing the image sensing unit to acquire second sensed image data during light projection by the light projection unit a predetermined time after the first sensed image data is acquired in the first image acquisition step;

a comparison step of comparing the first sensed image data with the second sensed image data, which are acquired in the first image acquisition step and the second image acquisition step, respectively; and

a detection step of detecting a position and size of a red eye on the basis of a comparison result in the comparison step.

28. A control method for an image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a first control step of causing the red-eye relaxation light projection unit to execute red-eye relaxation; and

a second control step of executing image sensing by using the electronic flash unit after control in the first control step,

the first control step comprising

a storage/holding step of causing the red-eye relaxation light projection unit to start projecting red-eye relaxation light, causing the image sensing unit to execute preliminary image sensing every predetermined time, and storing/holding latest first sensed image data and the second sensed image data the predetermined time before,

a comparison step of comparing the first sensed image data with the second sensed image data,

a red-eye determination step of determining a position and size of a red eye on the basis of a comparison result in the comparison step, and

a processing determination step of determining, on the basis of a determination result in the red-eye determination step, whether processing is to shift to the second control step, and if shift is to be executed, whether red-eye correction is to be executed, and whether red-eye relaxation by the red-eye relaxation light projection unit is to be continued, and

the second control step comprising

an image sensing step of causing the image sensing unit to execute image sensing unit while causing the electronic flash unit to emit electronic flash light, and

a correction step of correcting image data of a red component in a region corresponding to the position and size of the red eye determined in the red-eye determination step when it is determined in the processing determination step that red-eye correction is to be executed.

29. A control method for an image sensing apparatus comprising an image sensing unit, a red-eye relaxation light projection unit, and an electronic flash unit, characterized by comprising:

a first image acquisition step of causing the image sensing unit to acquire first sensed image data during light projection by the electronic flash unit;

a second image acquisition step of causing the image sensing unit to acquire second sensed image data during light projection by the light projection unit a predetermined time after the first sensed image data is acquired in the first image acquisition step;

a comparison step of comparing the first sensed image data with the second sensed image data, which are acquired in the first image acquisition step and the second image acquisition step, respectively;

a detection step of detecting a position and size of a red eye on the basis of a comparison result in the comparison step; and

a correction step of correcting, of the first sensed image data, image data of a red component in a region corresponding to the position and size of the red eye detected in the detection step.