JP2007251904A5

JP2007251904A5 -

Info

Publication number: JP2007251904A5
Application number: JP2006076444A
Authority: JP
Filing date: 2006-03-20
Publication date: 2009-04-23

Claims

A two-dimensional image of a subject can be captured with a first exposure time and a second exposure time that overlap at least partially, and a first video signal captured with the first exposure time is stored. And a second line memory for storing the second video signal imaged at the second exposure time, and corresponding to the first and second line memories. An image sensor that can output video signals in parallel;
The two-dimensional image is divided into a plurality of areas, a signal obtained from the first line memory corresponding to each area is selectively extracted, and an integrated value is obtained for each of the plurality of areas. Low luminance average value calculating means for extracting n low luminance areas in order of increasing luminance level and calculating the luminance average value of the n low luminance areas;
The two-dimensional image is divided into a plurality of areas, a signal from the second line memory corresponding to each area is selectively extracted, and an integrated value is obtained for each of the plurality of areas. High luminance average value calculating means for comparing the integrated values, extracting m high luminance areas in descending order of luminance level, and calculating average luminance values of the m high luminance areas;
An image pickup apparatus comprising: means for generating first and second control signals for individually controlling the first and second exposure times based on the calculation results of the respective luminance average values.

A first line memory capable of capturing a two-dimensional image of a subject with a first exposure time and a second exposure time, and storing a first video signal imaged with the first exposure time; A second line memory for storing a second video signal imaged at the second exposure time, and the sum of the first exposure time and the second exposure time is less than 1/30 fps, and An image sensor capable of outputting in parallel the corresponding video signal between the first and second line memories;
First luminance average value calculating means for calculating a luminance average value of the first signal output from the first line memory;
First control signal generating means for generating a first control signal for individually controlling the amount of light to obtain the first video signal based on the result of the first luminance average value calculating means;
Second luminance average value calculating means for calculating a luminance average value of the second signal output from the second line memory;
Second control signal generating means for generating a second control signal for individually controlling the amount of light to obtain the second video signal based on the result of the second luminance average value calculating means;
An imaging apparatus comprising:

The first video signal is a signal detected at a first exposure time;
3. The imaging apparatus according to claim 1, wherein the second video signal is a signal detected in a second exposure time that is shorter than the first exposure time. 4. .

The image sensor can perform double imaging using the same pixel at the first exposure time and the second exposure time, and the first exposure time and the second exposure time are temporal. The imaging apparatus according to claim 1, wherein a part of the imaging apparatus overlaps.

5. The image pickup apparatus according to claim 4, wherein the image sensor erases the accumulated signal charge and accumulates the signal charge again when the signal charge accumulated in the pixel exceeds a predetermined threshold.

Each pixel of the image sensor is
A row selection transistor and an amplification transistor connected in series between a power source and a signal line;
A reset transistor connecting the power source and the gate of the amplification transistor;
A photodiode connected to one end and a read transistor connected to the floating diffusion at the other end,
A transfer gate pulse for transferring charge from the floating diffusion is supplied to the gate of the row selection transistor, and a reset pulse for erasing the charge accumulated in the floating diffusion is supplied to the gate of the reset transistor. 3. The imaging apparatus according to claim 1, wherein a readout pulse for accumulating electric charges in the floating diffusion is supplied to the gate.

In the middle of the first exposure time, the reset pulse is applied to the gate of the row selection transistor to push down the potential barrier of the reset transistor and erase the signal charge accumulated in the floating diffusion. The imaging device according to claim 6.

8. The signal charge accumulated corresponding to the second exposure time is read out by applying the readout pulse to the gate of the readout transistor in the middle of the first exposure time. Imaging device.

An image for obtaining a first video signal imaged at a first exposure time and a second video signal imaged at a second exposure time longer than the first exposure time for a two-dimensional image of the subject. A sensor,
The two-dimensional image is divided into a plurality of areas, the first video signal corresponding to each area is selectively extracted to obtain a luminance integrated value for each of the plurality of areas, and n in ascending order of luminance level. Low luminance average value calculating means for extracting the low luminance areas and calculating the average luminance value of the n low luminance areas;
The two-dimensional image is divided into a plurality of areas, the second video signal corresponding to each area is selectively extracted to obtain a luminance integrated value for each of the plurality of areas, and m in order from the highest luminance level. High brightness average value calculating means for extracting the high brightness area of the m and calculating the brightness average value of the m high brightness areas;
Means for generating first and second control signals for individually controlling the first and second exposure times based on the calculation results of the respective luminance average values;
Signal processing means for removing an ambient light component from the second video signal to obtain an object light component video signal;
An imaging apparatus comprising:

The image sensor is capable of capturing an image with a first exposure time and a second exposure time at least partially overlapping each other, and stores the first video signal imaged with the first exposure time. A first line memory and a second line memory for storing a second video signal picked up at the second exposure time, and corresponding video signals between the first and second line memories The imaging apparatus according to claim 9, which can output in parallel.

The image sensor is capable of capturing a two-dimensional image of a subject with a first exposure time and a second exposure time, and stores a first video signal imaged with the first exposure time. 1 line memory and a second line memory for storing the second video signal imaged at the second exposure time, and the sum of the first exposure time and the second exposure time is 1 / frame. The imaging apparatus according to claim 9, wherein the imaging apparatus has a frequency lower than that and can output corresponding video signals between the first and second line memories in parallel.

The imaging apparatus according to claim 9, wherein the signal processing unit includes a first two-dimensional low-pass filter group for removing ambient light from each of the first and second video signals.

10. The imaging apparatus according to claim 9, wherein the signal processing means includes means for subtracting outputs of the first two-dimensional low-pass filter group from the first and second video signals.

The signal processing means includes a second two-dimensional low-pass filter group for removing halation generated in the vicinity of the contour portion of the object from the first and second video signals. Item 10. The imaging device according to Item 9.

The imaging apparatus according to claim 9, wherein the signal processing means includes first conversion means for performing Retinex conversion.

16. The imaging apparatus according to claim 15, wherein the signal processing means further includes second conversion means for performing Retinex conversion on the first video signal.

16. The image processing apparatus according to claim 15, further comprising a combining unit that combines either the first video signal or the first video signal subjected to the Retinex conversion with the second video signal subjected to the Retinex conversion. Or the imaging device of 16.