IMAGE PROCESSING APPARATUS CAPABLE OF MOVIE RECORDING, IMAGE PICKUP APPARATUS, CONTROL METHOD THEREFOR, AND STORAGE MEDIUM

• US 20150172595A1
• Filed: 12/11/2014
• Published: 06/18/2015
• Est. Priority Date: 12/16/2013
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: FURUMOCHI, Hiroyuki
• Granted Patent: US 9,838,632 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 23/667 Camera operation mode switching, e.g. between still and video, sport and normal or high- and low-resolution modes
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/73 by influencing the exposure time
• CPC Class Codes: H04N 25/44 by partially reading an SSIS array
• CPC Class Codes: H04N 25/533 by using differing integration times for different sensor regions
• CPC Class Codes: H04N 25/75 Circuitry for providing, modifying or processing image signals from the pixel array
• CPC Class Codes: H04N 5/772 the recording apparatus and the television camera being placed in the same enclosure
• CPC Class Codes: H04N 9/8042 involving data reduction

Abstract

An image processing apparatus that correctly acquires evaluation values when movie recording is performed at a fixed frame rate. A first readout unit reduces readout rows of an image pickup device, and acquires and outputs image data for movie recording from the reduced readout rows. A second readout unit acquires image data from readout rows that do not overlap with that by the first readout unit at higher rate than the first readout unit, and outputs the acquired image data simultaneously with the first readout unit. Whether a subject'"'"'s state changes for both the image data acquired by the first and second readout units is determined. If it is determined that the subject'"'"'s state in the image data acquired by the second readout unit is changed, a speed at which the second readout unit acquires image data is changed while the first readout unit maintains a fixed speed.

Claims

1. An image processing apparatus that controls driving of an image pickup device to record a movie, the image processing apparatus comprising:

a first readout unit configured to reduce readout rows of the image pickup device, and to acquire and output image data for movie recording from the reduced readout rows;

a second readout unit configured to, in the image pickup device, acquire image data from readout rows that do not overlap with the readout rows read out by said first readout unit, at higher rate than said first readout unit, and output the acquired image data simultaneously with said first readout unit;

a determination unit configured to determine whether a state of a subject changes or not, with respect to both the image data acquired by said first readout unit and the image data acquired by said second readout unit; and

a changing unit configured to, if said determination unit determines that the state of the subject in the image data acquired by said second readout unit changes, change a speed at which said second readout unit acquires image data in accordance with the change in the state of the subject, while said first readout unit acquires image data at a fixed speed.

2. The image processing apparatus according to claim 1, wherein when said determination unit determines that the state of the subject in the image data acquired by said second readout unit changes into a low luminance, said changing unit changes the speed at which said second readout unit acquires image data, so as to extend an exposure time for the image pickup device.

3. The image processing apparatus according to claim 1, wherein when said determination unit determines that the state of the subject in the image data acquired by said first readout unit changes into a low luminance, said changing unit changes the speed at which said second readout unit acquires image data, so as to extend an exposure time for the image pickup device, and

after extending the exposure time, an evaluation value of the state of the subject based on the image data acquired by said second readout unit is reflected to an output of said first readout unit.

4. The image processing apparatus according to claim 2, wherein said changing unit lowers the speed at which said second readout unit acquires image data.

5. An image pickup apparatus, comprising:

an image pickup device configured to have a plurality of pixels arranged in a two-dimensional array; and

a control unit configured to individually control readout rates for respective areas of said image pickup device,

wherein in a case where an image signal is repeatedly read out from a first area of said image pickup device for movie recording, said control unit changes a readout rate for a second area, which is different from the first area, according to a luminance of a subject while maintaining a readout rate for the first area.

6. The image pickup apparatus according to claim 5, further comprising a calculation unit configured to calculates the luminance of the subject based on at least one of a first image pickup signal readout from the first area and a second pickup signal readout from the second area,

wherein said control unit changes the readout rate for the second area according to the luminance of the subject calculated by said calculation unit.

7. The image pickup apparatus according to claim 5, wherein said control unit sets the readout rate for the second area in a case where the luminance of the subject is less than a predetermined value longer than a case where the luminance of the subject is equal or more than the predetermined value.

8. The image pickup apparatus according to claim 5, wherein said control unit changes an exposure time for the first area according to the luminance of the subject.

9. The image pickup apparatus according to claim 5, wherein said control unit changes an exposure time for the second area according to the luminance of the subject.

10. A control method of an image processing apparatus that control driving of an image pickup device to record a movie, the control method comprising:

a first readout step of reducing readout rows of the image pickup device, and of acquiring and outputting image data for movie recording from the reduced readout rows;

a second readout step of, in the image pickup device, acquiring image data from readout rows that do not overlap with the readout rows read out in said first readout step, at higher rate than said first readout step, and outputting the acquired image data simultaneously with said first readout step;

a determination step of determining whether a state of a subject changes or not, with respect to both the image data acquired in said first readout step and the image data acquired in said second readout step; and

a changing step of, if it is determined in said determination step that the state of the subject in the image data acquired in said second readout step changes, changing a speed at which image data is acquired in said second readout step in accordance with the change in the state of the subject, while image data is acquired at a fixed speed in said first readout step.

11. A control method for an image pickup apparatus including an image pickup device having a plurality of pixels arranged in a two-dimensional array, the control method comprising:

a control step of individually controlling readout rates for respective areas of the image pickup device,

wherein in a case where an image signal is repeatedly read out from a first area of the image pickup device for movie recording, a readout rate for a second area, which is different from the first area, is changed in said control step according to a luminance of a subject while maintaining a readout rate for the first area.

12. A non-transitory computer readable storage medium that stores a program configured to cause a computer to execute a control method of an image processing apparatus that controls driving of an image pickup device to record a movie, the control method comprising:

a first readout step of reducing readout rows of the image pickup device, and of acquiring and outputting image data for movie recording from the reduced readout rows;

a second readout step of, in the image pickup device, acquiring image data from readout rows that do not overlap with the readout rows read out in said first readout step, at higher rate than said first readout step, and outputting the acquired image data simultaneously with said first readout step;

a determination step of determining whether a state of a subject changes or not, with respect to both the image data acquired in said first readout step and the image data acquired in said second readout step; and

a changing step of, if it is determined in said determination step that the state of the subject in the image data acquired in said second readout step changes, changing a speed at which image data is acquired in said second readout step in accordance with the change in the state of the subject, while image data is acquired at a fixed speed in said first readout step.

13. A non-transitory computer readable storage medium that stores a program configured to cause a computer to execute a control method for an image pickup apparatus including an image pickup device having a plurality of pixels arranged in a two-dimensional array, the control method comprising:

a control step of individually controlling readout rates for respective areas of the image pickup device,

wherein in a case where an image signal is repeatedly read out from a first area of the image pickup device for movie recording, a readout rate for a second area, which is different from the first area, is changed in said control step according to a luminance of a subject while maintaining a readout rate for the first area.