JP2010273147A - Imaging signal specific state detection device, imaging device, imaging signal specific state detection method, program, and integrated circuit - Google Patents

Abstract

A CMOS imaging device has a problem that white-band interference occurs when an external flash such as a flash is blown. An object of the present invention is to provide an imaging signal specific state detection device that detects the interference with high accuracy.
An imaging signal specific state detection apparatus 200 outputs an imaging signal of a subject imaged from a lens unit, and an average luminance for one frame of the imaging signal output from the imaging unit 1. The first average luminance level calculation unit 2 to be obtained, the first storage unit 3 that stores the output signal of the first average luminance level calculation unit 2, the output signal of the first average luminance level calculation unit 2, and the first storage unit 3 A second average luminance level calculation unit 4 that calculates an average luminance level for two frames from the output signal, a second storage unit 10 that stores an output signal of the second average luminance level calculation unit 4, and a second average luminance level calculation A determination unit that determines a specific state of the imaging signal output from the imaging unit from the output signal of the unit and the output signal of the second storage unit;
[Selection] Figure 4

Description

  The present invention relates to an imaging signal specific state detection device, an imaging device, an imaging signal specific state detection method, a program, and an integrated circuit capable of detecting with high accuracy white band interference caused by a still camera or other flash when shooting a moving image for video. .

2. Description of the Related Art In recent years, imaging apparatuses using CMOS (Complementary Metal Oxide Semiconductor) imaging elements having features such as small size, low power consumption, and high-speed imaging have made great progress in the fields of consumer video cameras and commercial video cameras.
The CMOS type image pickup device has various characteristics as compared with a CCD (Charge Coupled Device) type image pickup device. The CMOS type image pickup device and the CCD type image pickup device have a photodiode (Photo Diode: hereinafter referred to as “PD”). The reading method of the electric charge accumulated in the description is also different.
In the CCD type image pickup device, the charge readout of the PD is performed by a so-called global shutter method in which all pixels are read at the same timing as in the CCD. On the other hand, in a CMOS type image sensor, PD charge reading is performed by a so-called rolling shutter system in which reading timing is shifted in units of lines (pixels). For this reason, the bad effect which a CCD type image sensor does not generate | occur | produce also occurs. In the CMOS image sensor, the readout timing of the accumulated charge is shifted, so that the timing of the accumulation period of each pixel is shifted, which causes a problem that is not found in the CCD image sensor.

One of the problems is a phenomenon that white band-like interference occurs on the imaging screen when a subject such as a still camera that has flash light is imaged with a video camera of a CMOS imaging device. Here, “white belt-like interference” is a phenomenon in which only a part of a frame with a captured image is affected by flash light, and only the upper part (upper part of the screen) or the lower part (lower part of the screen) becomes brighter from the middle line. Point to.
Hereinafter, this phenomenon will be described with reference to FIGS.
FIG. 10 is a diagram schematically showing a shooting scene where a video camera and a still camera are mixed, for example, a shooting scene such as a press conference.
FIG. 10 schematically shows a shooting scene composed of a video camera 1000, a monitor 1001, a still camera 1002, 1003, and a subject 1004 that display the image signal. The video camera 1000 uses a CMOS image sensor.

When the still camera 1002, 1003 is used in such a shooting scene, a white belt-like disturbance occurs on the screen of the monitor 1001 that displays the image signal of the video camera 1000. The principle will be described below.
FIG. 11 is a diagram schematically illustrating a charge accumulation period (exposure period), a readout timing, a readout period, and a scanning period of the video camera 1000.
In FIG. 21, the charge accumulation period of each scanning line constituting the screen (the image captured by the video camera 100) and the scanning period for reading out the charge are shown with the time axis as the horizontal axis. The total number of scanning lines is 1125 lines assuming an HD camera. Further, the “monitor screen 0 period” shown in FIG. 21 is a period in which the imaging signal of frame 0 is output to the monitor screen or the like, and is 1/60 seconds here. The same applies to “monitor screen 1 period” and the like.

In the video camera 1000, for example, the line 1 (the pixel corresponding to one line on the image pickup element surface of the CMOS type image pickup element for acquiring the video signal forming the line 1 is the uppermost line on the screen) PD) is installed at the same time as the start timing of the monitor screen 0 period, and the PD accumulation of the frame 1 (charge accumulation at the PD) is started at the same time as the monitor screen 0 period. At the same time, the PD accumulation ends. The accumulated PD signal of line 1 is immediately after this (immediately after the completion of PD accumulation), and scanning of accumulated charge is read (“reading of accumulated charge” may be simply referred to as “read”). At the same time, the PD accumulation of the next frame 2 is started. The PD signal readout scanning period is 1/60 / 1125≈1.48 × 10 ⁻⁵ seconds because 1125 lines are scanned in one frame period (1/60 seconds).

Next, for line 2, PD accumulation is started in accordance with the PD read scan period end timing for frame 0 of line 1. That is, for the line 2, PD accumulation and readout operations are performed with a delay of the PD readout scanning period with respect to the line 1. The same operation as described above is performed for the line 3 and subsequent lines.
Thus, in the rolling shutter system, the charge accumulation period of each line constituting one frame is slightly shifted from top to bottom as shown in FIG. Accordingly, the scanning period of each line, that is, the PD signal readout timing is also immediately after the charge accumulation period of each line as shown in FIG. That is, in the video camera 1000 using the CMOS image sensor, the PD signal reading process is sequentially performed in the line order, such as reading the line 1 PD signal and then reading the line 2 PD signal. .

As shown in FIG. 11, when the flash is fired near the center of the monitor screen 1 period (the period indicated by “flash emission period” in FIG. 21), the charge accumulation period in the second half of frame 1 and the charge accumulation period in the first half of frame 2 The bright light of the flash will affect it. As shown in FIG. 11, the flash lit during the period of the monitor screen 1 crosses the charge accumulation and charge read timings of the frames 1 and 2 on the line X and the line Y.
That is, the influence of the bright light of the flash in the case shown in FIG. 21 is as follows.
(Line a1 of frame 1 (line belonging to the portion indicated by “a1” in FIG. 21)):
In the frame 1, the part of the line a1 before the line X is not affected by the flash light (the charge accumulation period has already ended).
(Line X to line Y of frame 1 (line belonging to the portion indicated by “a2” in FIG. 21)):
The line a2 portion in the period between the line X and the line Y is affected by the flash light in the frame 1, and the accumulated light quantity gradually increases.
(After line Y of frame 1 (a line belonging to a portion indicated by “a3” in FIG. 21)):
The portion of line a3 after line Y is affected by the total amount of flash light.
(Line b1 of frame 2 (line belonging to the portion indicated by “b1” in FIG. 21)):
In frame 2, conversely, the portion of line b1 before line X is affected by the total amount of flash light.
(Line X to line Y of frame 2 (a line belonging to a portion indicated by “b2” in FIG. 21)):
The portion of the line b2 in the period between the line X and the line Y gradually becomes less affected by the flash light.
(After the line Y of the frame 2 (a line belonging to a portion indicated by “b3” in FIG. 21)):
Then, since the accumulation period has not yet started in the portion of the line b3 after the line Y, it is not affected by the flash light.

  Therefore, assuming that the flash light emission period is momentary and the transient periods a2 and b2 in FIG. 21 do not exist, the monitor screen is roughly shown in FIG. The lower half of the screen (image) to be formed is bright, and the upper half of the monitor screen 2 (screen (image) formed by the image pickup signal of frame 2) is bright. Projected. On the other hand, the monitor screen originally desired at the time of flash emission is a screen that is bright as a whole like the ideal monitor screen shown in the lower part of FIG. In the case of an image pickup apparatus using a CCD type image pickup device, unlike the CMOS, the charge accumulation timings of all the lines constituting one frame are the same. Therefore, such a problem does not occur. The ideal monitor screen as shown in is displayed.

As described above, in an imaging apparatus using a CMOS type imaging device, there is a problem that when an external flash light such as a flash light enters, a white belt-like interference occurs in an image formed by the imaging signal.
As an imaging apparatus including a conventional imaging signal specific state detection apparatus that solves this problem, there is an imaging apparatus described in Patent Document 1.
FIG. 13 is a block diagram illustrating a configuration example of an imaging apparatus 900 including a conventional imaging signal specific state detection apparatus. The imaging apparatus 900 is a digital still camera that mainly records so-called still images.
As illustrated in FIG. 13, the imaging device 900 includes a lens unit 912, an imaging unit 113, an image processing unit 114, a buffer 115, a recording display processing unit 116, a buffer 117, a recording unit 118, a display unit 119, an evaluation unit 120, and a storage. Unit 121, operation unit 122, and control unit 123.

The lens unit 912 includes an optical system such as a lens mechanism 131 and a diaphragm (iris) mechanism 132, and condenses light from a subject incident thereon on the image sensor 141 of the imaging unit 113.
The imaging unit 113 includes an imaging device 141, a CDS (Correlated Double Sampling) circuit 142, an A / D (Analog / Digital) circuit 143, a signal generator (SG) 144, and a timing generator (TG) 145, and images a subject. Then, an image obtained as a result is supplied to the image processing unit 114.
The image sensor 141 is configured by, for example, a CCD type image sensor, a CMOS type image sensor, or the like. The image sensor 141 receives light from a subject incident through the lens unit 912 and photoelectrically converts the image signal as an electric signal. Obtain and output. The image sensor 141 is configured by a plurality of pixels that accumulate charges in accordance with the amount of received light and are arranged in a plane in a lattice arrangement, and is perpendicular to the horizontal drive signal supplied from the timing generator 145. In accordance with the drive signal, light from the lens unit 912 is received for a predetermined exposure time. Charges corresponding to the amount of received light are accumulated in each pixel of the image sensor 141, and the image sensor 141 supplies the charges to the CDS circuit 142 as an analog image signal.

The CDS circuit 142 removes the noise component of the analog image signal supplied from the image sensor 141 by performing correlated double sampling. The CDS circuit 142 supplies the image signal from which the noise component has been removed to the A / D circuit 143.
The A / D circuit 143 performs A / D conversion on the analog image signal from the CDS circuit 142 and supplies the resulting digital image data to the image processing unit 114.
Based on the control of the control unit 123, the signal generator 144 generates a horizontal synchronization signal and a vertical synchronization signal, respectively, and outputs them to the timing generator 145.
The timing generator 145 generates a horizontal drive signal and a vertical drive signal for driving the image sensor 141 based on the horizontal synchronization signal and the vertical synchronization signal supplied from the signal generator 144, and supplies them to the image sensor 141. .

The image processing unit 114 includes a Y-C separation circuit 151, a filter circuit 152, a WB (White Balance) circuit 153, and an aperture control gamma circuit 154. The image processing unit 114 applies predetermined image data to the image data supplied from the A / D circuit 143 of the imaging unit 113. The image processing is performed.
The image processing unit 114 supplies the image (image data) subjected to the image processing to the recording / display processing unit 116 and the evaluation unit 120.
The Y-C separation circuit 151 performs Y-C separation processing for separating the image data from the imaging unit 113 into a luminance signal (Y) and a chroma signal (C).
The filter circuit 152 performs a noise reduction process that filters the image data from the imaging unit 113 and cuts a noise component included in the image data.
The WB circuit 153 performs a process of adjusting the white balance of the image by multiplying the image data from the imaging unit 113 by a gain so that the R, G, and B levels of the white subject are equal, for example.

The aperture control gamma circuit 154 performs processing for adjusting image quality such as aperture correction that emphasizes the edge portion of the image and gamma correction that adjusts the hue of the image, on the image data from the imaging unit 113.
The buffer 115 stores data that needs to be temporarily stored when the image processing unit 114 performs image processing.
The recording display processing unit 116 is supplied with an image (data) subjected to image processing from the image processing unit 114, and performs recording control for recording the image on the recording unit 118 and display control for displaying the image on the display unit 119. .
The buffer 117 stores data that needs to be temporarily stored when the recording / display processing unit 116 performs recording control or display control.

The display unit 119 includes, for example, an LCD (Liquid Crystal Display) panel, and displays an image captured by the imaging unit 113 and supplied from the recording display processing unit 116.
The evaluation unit 120 includes a detection circuit 161 that detects image brightness and color distribution, and an image captured by the image sensor 141 is supplied from the image processing unit 114.
The detection circuit 161 detects the image supplied from the image processing unit 114, and information obtained as a result thereof, for example, information indicating the brightness and color distribution of a predetermined part of the image, and the spatial frequency of the predetermined part of the image Is output as an evaluation value for an image captured by the image sensor 141.
The evaluation unit 120 supplies the evaluation value output from the detection circuit 161 to the control unit 123.

The storage unit 121 is configured by a ROM (Read Only Memory), a RAM (Random Access Memory), an EEPROM (Electrically Erasable and Programmable Read Only Memory), or the like. A program, data necessary for the control unit 123 to perform processing, data that must be retained even when the power of the imaging apparatus 900 is turned off, and the like are stored.
The operation unit 122 includes, for example, a shutter button and a recording button (not shown) and is operated by the user. The operation unit 122 supplies a signal requesting to capture a still image and a signal requesting start or stop of moving image capturing to the control unit 123 in accordance with a user operation.

The control unit 123 includes a CPU (not shown) and an arithmetic circuit 171 that calculates a difference value. The control unit 123 is supplied with an evaluation value for the image captured by the image sensor 141 from the evaluation unit 120, and temporarily stores the evaluation value supplied from the evaluation unit 120 in the storage unit 121.
The arithmetic circuit 171 calculates a difference value between two predetermined evaluation values, and the control unit 123 controls each unit of the imaging apparatus 900 based on the difference value calculated by the arithmetic circuit 171.
For example, when a still image or a moving image is captured in response to a user operation, the control unit 123 controls each unit of the imaging device 900 based on the difference value calculated by the arithmetic circuit 171 and external flashes. If it is determined that the image has been adversely affected by the external flash, the image is excluded, and if it is determined that the image has not been adversely affected by the external flash, the image is recorded in the recording unit 118.

  In this way, the imaging apparatus 900 including the conventional imaging signal specific state detection apparatus solves the problem of white band interference caused by an external flash.

JP 2007-306225 A

  However, in the image pickup apparatus including the conventional image pickup signal specific state detection apparatus, the white band-like disturbance caused by an external flash such as a flash is detected based on the difference value of the evaluation value of each image to be compared with the image to be recorded. Therefore, depending on the image, there is a case where the difference value does not exceed the reference level and is erroneously detected. For example, in the conventional imaging apparatus 900, it is conceivable to employ a method of calculating the average value of the luminance levels of the entire screen as the evaluation value of the captured image. In that case, in the imaging apparatus 900, the evaluation unit 120 temporarily stores the average luminance level value obtained by sequentially integrating and averaging the luminance signals for each frame in the storage unit 121 via the control unit 123. In addition, the average luminance level is similarly calculated at the timing when the image of the next frame is input, and compared with the average luminance level of the previous frame stored in the storage unit 121, so that the presence or absence of the influence of the external flash Judging.

However, with this method, when there is an external flash effect on a small part of the bottom of the screen, the average brightness level of the entire screen does not show a clear difference from the average brightness level of the frame that is not affected by the external flash. It is difficult to determine the presence or absence of flash effects.
The present invention solves the above-described conventional problems, and an imaging signal specific state detection device, an imaging device, and an imaging signal that can detect white-band interference caused by an external flash such as a flash with higher accuracy than conventional methods. A specific state detection method, a program, and an integrated circuit are provided.

1st invention is an imaging signal specific state detection apparatus provided with an imaging part, a 1st average brightness level calculation part, a 1st memory | storage part, a 2nd average brightness level calculation part, and a determination part.
The imaging unit converts light from the subject into an electrical signal and acquires it as an imaging signal. The first average luminance level calculation unit obtains a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit. The first storage unit can store the first average luminance level and output the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level. The second average luminance level calculation unit performs an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. The determination unit determines a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for two frames calculated by the second average luminance level calculation unit.

In this imaging signal specific state detection device, the determination unit determines the specific state of the imaging signal acquired by the imaging unit based on the average luminance level for two frames calculated by the second average luminance level calculation unit. Therefore, the imaging signal specific state detection device can appropriately determine which part of the imaging signal is affected by the external flash in an environment where the external flash has occurred.
2nd invention is 1st invention, Comprising: The determination part has a comparison determination part and a flag signal generation | occurrence | production part.
The comparison determination unit compares the average luminance level for two frames with the first threshold value and outputs information indicating the comparison result. When the flag signal generation unit determines that the average luminance level for two frames exceeds the first threshold based on the information indicating the comparison result output from the comparison determination unit, the flag signal generation unit A flag signal indicating that the frame and the frame immediately before the current frame are affected by an external flash is generated.

Thereby, in this imaging signal specific state detection device, the influence of the external flash (occurrence of white band interference) on the frame in which the flag signal is output and the frame one frame before the flag signal output from the determination unit. Can be identified.
According to a third aspect of the present invention, there is provided an imaging signal specifying state including an imaging unit, a first average luminance level calculation unit, a first storage unit, a second average luminance level calculation unit, a second storage unit, and a determination unit. It is a detection device.
The imaging unit converts light from the subject into an electrical signal and acquires it as an imaging signal. The first average luminance level calculation unit obtains a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit. The first storage unit can store the first average luminance level and output the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level. The second average luminance level calculation unit performs an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. The second storage unit stores the average luminance level for the second frame calculated by the second average luminance level calculation unit, and the average luminance level for two frames stored after being delayed by a predetermined time is averaged for the delayed two frames. Can be output as The determination unit includes an average luminance level for two frames calculated by the second average luminance level calculation unit, and an average luminance level for two delayed frames output with a delay corresponding to one frame from the second storage unit. Based on the above, the specific state of the imaging signal acquired by the imaging unit is determined.

In this imaging signal specific state detection device, the determination unit outputs the average luminance level for two frames calculated by the second average luminance level calculation unit and the second storage unit with a delay by a time corresponding to one frame. The specific state of the imaging signal acquired by the imaging unit is determined on the basis of the average luminance level for two delayed frames. Therefore, in this imaging signal specific state detection device, it is possible to appropriately determine which part of the imaging signal is affected by the external flash in the environment where the external flash has occurred.
4th invention is 3rd invention, Comprising: The determination part has a difference calculating part and a flag signal generation part.
The difference calculation unit obtains a difference signal by subtracting the average luminance level for two delayed frames from the average luminance level for two frames.

The flag signal generation unit sets the average luminance level for two frames to L, sets the average luminance level for two delayed frames to DL, sets the difference signal acquired by the difference calculation unit to Diff, and the current frame that is the processing target frame is the first frame. When N frames (N is an integer), the following (1) to (3) are satisfied, and the (N-1) th and (N-2) th frames are affected by external flash. A flag signal indicating this is generated. That is, the flag signal generator
(1) In the (N-2) th frame, which is a frame two frames before the Nth frame,
L-DL> th (th is a number satisfying th ≧ 0)
And satisfy
(2) In the (N−1) th frame, which is a frame one frame before the Nth frame,
L-DL> th (th is a number satisfying th ≧ 0)
And satisfy
(3) In the Nth frame,
L-DL <-th (th is a number satisfying th ≧ 0)
If the flag signal generation unit satisfies the condition, the flag signal generation unit generates a flag signal indicating that it is affected by the external flash in the (N-1) th frame and the (N-2) th frame.

Since this imaging signal specific state detection device can detect and evaluate an increase or decrease in average luminance for two frames, white-band interference caused by external flash emission (external flash) has occurred (influence of external flash). The imaging signal (frame) received can be detected with high accuracy.
5th invention is an imaging device provided with the imaging signal specific state detection apparatus which is one of the 1st to 4th invention.
Thereby, an imaging device provided with the imaging signal specific state detection device according to any one of the first to fourth inventions can be realized.
6th invention is an imaging signal specific state detection method used for an imaging signal specific state detection apparatus provided with an imaging part which converts light from a subject into an electrical signal and acquires it as an imaging signal, and calculates the first average luminance level A step, a first storage step, a second average luminance level calculation step, and a determination step.

In the first average luminance level calculation step, a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit is obtained. In the first storage step, the first average luminance level can be stored, and the first luminance level stored after being delayed for a predetermined time can be output as the delayed first average luminance level. In the second average luminance level calculation step, an average process is performed on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame in the first storage step. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. In the determination step, the specific state of the imaging signal acquired by the imaging unit is determined based on the average luminance level for two frames calculated in the second average luminance level calculation step.
As a result, it is possible to realize an imaging signal specific state detection method that exhibits the same effect as that of the first invention.

A seventh aspect of the invention is a program for causing a computer to execute an imaging signal specific state detection method used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and obtains it as an imaging signal. The imaging signal specific state detection method includes a first average luminance level calculation step, a first storage step, a second average luminance level calculation step, and a determination step.
In the first average luminance level calculation step, a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit is obtained. In the first storage step, the first average luminance level can be stored, and the first luminance level stored after being delayed for a predetermined time can be output as the delayed first average luminance level. In the second average luminance level calculation step, an average process is performed on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame in the first storage step. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. In the determination step, the specific state of the imaging signal acquired by the imaging unit is determined based on the average luminance level for two frames calculated in the second average luminance level calculation step.

Accordingly, it is possible to realize a program that causes a computer to execute an imaging signal specific state detection method that exhibits the same effect as that of the first invention.
An eighth invention is an integrated circuit used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and acquires the electrical signal, and includes a first average luminance level calculation unit, 1 memory | storage part, a 2nd average brightness level calculation part, and the determination part are provided.
The first average luminance level calculation unit obtains a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit. The first storage unit can store the first average luminance level and output the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level. The second average luminance level calculation unit performs an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. The determination unit determines a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for two frames calculated by the second average luminance level calculation unit.

As a result, an integrated circuit having the same effect as that of the first invention can be realized.
A ninth invention is an imaging signal specific state detection method used in an imaging signal specific state detection apparatus including an imaging unit that converts light from a subject into an electrical signal and acquires the electrical signal, and calculates a first average luminance level A step, a first storage step, a second average luminance level calculation step, a second storage step, and a determination step.
In the first average luminance level calculation step, a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit is obtained.
The first storage step can store the first average luminance level, and output the stored first luminance level after being delayed for a predetermined time as a delayed first average luminance level. In the second average luminance level calculation step, an average process is performed on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame in the first storage step. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. The second storing step stores the average luminance level for the second frame calculated by the second average luminance level calculating step, and the average luminance level for two frames stored after being delayed by a predetermined time is averaged for the delayed two frames. Can be output as In the determination step, the average luminance level for two frames calculated in the second average luminance level calculating step, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage step, Based on the above, the specific state of the imaging signal acquired by the imaging unit is determined.

Thereby, the imaging signal specific state detection method that exhibits the same effect as that of the third invention can be realized.
A tenth aspect of the invention is a program that causes a computer to execute an imaging signal specific state detection method used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and acquires the electrical signal. The imaging signal specific state detection method includes a first average luminance level calculation step, a first storage step, a second average luminance level calculation step, a second storage step, and a determination step.
In the first average luminance level calculation step, a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit is obtained. In the first storage step, the first average luminance level can be stored, and the first luminance level stored after being delayed for a predetermined time can be output as the delayed first average luminance level. In the second average luminance level calculation step, an average process is performed on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame in the first storage step. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. In the second storage step, the average luminance level for the second frame calculated in the second average luminance level calculation step is stored, and the average luminance level for two frames stored after being delayed by a predetermined time is averaged for the delayed two frames. Can be output as In the determination step, the average luminance level for two frames calculated in the second average luminance level calculating step, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage step, Based on the above, the specific state of the imaging signal acquired by the imaging unit is determined.

Thereby, the program which makes a computer perform the imaging signal specific state detection method which show | plays the effect similar to 3rd invention is realizable.
An eleventh aspect of the invention is an integrated circuit used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and acquires the electrical signal, and includes a first average luminance level calculation unit, 1 memory | storage part, 2nd average brightness level calculation part, 2nd memory | storage part, and the determination part are provided.
The first average luminance level calculation unit obtains a first average luminance level that is an average luminance level of the captured image for one frame formed by the imaging signal acquired by the imaging unit. The first storage unit can store the first average luminance level and output the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level. The second average luminance level calculation unit performs an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit. Thus, the average luminance level for two frames, which is the average luminance level for two frames, is calculated. The second storage unit stores the average luminance level for the second frame calculated by the second average luminance level calculation unit, and the average luminance level for two frames stored after being delayed by a predetermined time is averaged for the delayed two frames. Can be output as The determination unit includes an average luminance level for two frames calculated by the second average luminance level calculation unit, and an average luminance level for two delayed frames output with a delay corresponding to one frame from the second storage unit. Based on the above, the specific state of the imaging signal acquired by the imaging unit is determined.

  Thereby, an integrated circuit having the same effect as that of the third invention can be realized.

  According to the present invention, it is possible to detect and evaluate the increase / decrease in the average luminance for two frames, rather than using the evaluation value of the average luminance for one frame of each frame (a frame image formed by the imaging signal). It is possible to detect with high accuracy an imaging signal (frame) in which a white belt-like disturbance due to the flash emission (external flash) occurs (affected by the external flash).

The block diagram which shows schematic structure of the imaging signal specific state detection apparatus which concerns on 1st Embodiment. The block diagram which shows an example of the internal structure of the determination part 5 which concerns on 1st Embodiment. The signal waveform diagram of each part (a)-(e) shown in FIG.1 and FIG.2 of the imaging signal specific state detection apparatus which concerns on 1st Embodiment. The block diagram which shows schematic structure of the imaging signal specific state detection apparatus which concerns on 2nd Embodiment. The block diagram which shows an example of the internal structure of the determination part 11 which concerns on the 2nd Embodiment The signal waveform diagram of each part (a)-(g) shown in FIG.4 and FIG.5 of the imaging signal specific state detection apparatus which concerns on the 2nd Embodiment. The signal waveform diagram of each part (a)-(g) shown in FIG.4 and FIG.5 of the imaging signal specific state detection apparatus which concerns on the 2nd Embodiment. The signal waveform diagram of each part (a)-(g) shown in FIG.4 and FIG.5 of the imaging signal specific state detection apparatus which concerns on the 2nd Embodiment. Schematic diagram of a monitor screen showing an example of correction when imaging signal specific state detection according to the first embodiment or the second embodiment is used Schematic showing a shooting scene where a video camera imaging device and a still camera are mixed Explanatory drawing of the principle of white belt interference in a flash shooting environment in an imaging device using a CMOS image sensor Schematic diagram of a monitor screen for explaining white-band interference in a flash shooting environment in an imaging device using a CMOS image sensor The block diagram which shows the structure of the imaging device containing the conventional imaging signal specific state detection apparatus

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
<1.1: Configuration of Imaging Signal Specific State Detection Device>
FIG. 1 is a block diagram showing a schematic configuration of an imaging signal specific state detection device 100 according to the first embodiment of the present invention.
As shown in FIG. 1, the imaging unit 1 receives light from a lens unit (not shown), acquires an imaging signal by photoelectric conversion, and uses the acquired imaging signal as a first average luminance level calculation unit 2 and a signal. Output to the correction unit 6. The imaging unit 1 uses a CMOS image sensor.
The first average luminance level calculation unit 2 calculates an average value (average luminance level) of luminance levels for one frame of the imaging signal from the imaging unit 1 (one frame of a captured image formed by the imaging signal). Then, the first average luminance level calculation unit 2 outputs the calculated average value of the luminance levels to the first storage unit 3 and the second luminance average level calculation unit 4.

The first storage unit 3 receives and stores the average luminance level output from the first average luminance level calculation unit 2. The first storage unit 3 outputs the stored average luminance level to the second average luminance level calculation unit.
The second average luminance level calculation unit 4 receives the output signals of the first average luminance level calculation unit 2 and the first storage unit 3, calculates the average of the two signals, and outputs the calculation result to the determination unit 5. .
The determination unit 5 receives the output signal of the second average luminance level calculation unit, generates a determination signal for determining whether the imaging signal is affected by the external flash based on the output signal, The generated determination signal is output to the signal correction unit 6.
The signal correction unit 6 receives the output signals from the imaging unit 1 and the determination unit 5 and performs appropriate correction processing on the identified imaging signal.

FIG. 2 is a block diagram illustrating an example of an internal configuration of the determination unit 5.
As illustrated in FIG. 2, the determination unit 5 includes a comparison determination unit 51 and a flag signal generation unit 52.
The comparison determination unit 51 receives the output signal of the second average luminance level calculation unit 4 as an input. The comparison determination unit 51 compares the signal level of the output signal of the second average luminance level calculation unit 4 with a predetermined threshold th,
(1) When the signal level of the output signal exceeds the threshold th, the comparison determination signal indicating the determination result is set to “1” (the signal level corresponding to “1” of the binary signal), and the flag signal Output to the generator 52,
(2) When the signal level of the output signal does not exceed the threshold th, the comparison determination signal indicating the determination result is set to “0” (the signal level corresponding to “0” of the binary signal), and the flag signal Output to the generator 52.

  The predetermined threshold th may be set to a value that can appropriately detect the external flash in consideration of the system performance (camera performance) of the imaging signal specific state detection device 100. For example, in the imaging signal specific state detection apparatus 100, an imaging signal (AGC or the like processed from the imaging unit 1 is processed, and a standard state (a video signal adjusted to have a predetermined dynamic range desired in the camera system). When the dynamic range of the imaging signal) is 0 to 100% (W0% signal level is “0%” and W100% signal level is “100%”), The threshold value th is preferably set to a predetermined value of 60% or more, more preferably a predetermined value of 70% or more, and further preferably a predetermined value of 100% or more. Needless to say, this setting example is an example, and the present invention is not limited to this.

The flag signal generation unit 52 receives the comparison determination signal output from the comparison determination unit 51. When the comparison determination signal is “1”, the flag signal generation unit 52 outputs a flag signal (a flag signal for specifying the output frame) as a signal. Output to the correction unit 6.
<1.2: Operation of Imaging Signal Specific State Detection Device>
The operation of the imaging signal specific state detection device 100 configured as described above according to the present embodiment will be described below in detail with reference to FIGS.
3A to 3E are signal waveform diagrams showing signal waveforms of the respective parts (a) to (e) of the imaging signal specific state detection device 100 shown in FIGS. 1 and 2.
When an image is taken by the imaging signal specific state detection device 100 in an environment where an external flash is generated, an image (frame image) formed by the imaging signal output from the imaging unit 1 by the external flash is shown in FIG. As shown in a), it is assumed that white belt-like interference occurs in, for example, the (n + 2) frame and the (n + 3) frame. The other frames are not particularly illustrated, but are assumed to be frames (frames that are not affected by the external flash) in which all the frames are captured with a uniform brightness.

At this time, the output signal of the first average luminance level calculation unit 2 is as shown in FIG. Since the output signal of the first average luminance level calculation unit 2 is an average luminance level for each frame, the first average luminance level (first average luminance level calculation unit) in a white band-like (n + 3) frame having a large disturbance. 2) is a large value.
Next, since the output signal of the first storage unit 3 is a signal delayed by one frame by receiving and storing the output signal of the first average luminance level calculation unit 2, an output as shown in FIG. Signal.
Since the output signal of the second average luminance level calculation unit 4 receives the output signals of the first average luminance level calculation unit 2 and the first storage unit 3 and calculates the average value of these signals, FIG. Output signal. That is, the output signal of the second average luminance level calculation unit 4 is a signal obtained by calculating an average value for two frames of the current frame (processing target frame) and the signal one frame before, and as a result, Even if the white belt-like interference caused by flash photography (external flash) extends over two frames, the average luminance level for the two frames is likely to be larger than the average luminance level for any other two frames.

  The determination unit 5 monitors the output signal of the second average luminance level calculation unit 4 to detect white belt-like interference due to flash (external flash). As shown in FIG. 2, for example, the determination unit 5 includes a comparison determination unit 51 and a flag signal generation unit 52 that receives the output signal and outputs a flag signal. The comparison determination unit 51 compares the signal level of the output signal of the second average luminance level calculation unit 4 with a predetermined threshold th by the method described above, and acquires a comparison determination signal indicating the comparison determination result. Specifically, in the portion indicated by A in FIG. 3, since the output of the second average luminance level calculation unit exceeds the threshold th1, the comparison determination unit 51 sets the comparison determination signal to “1” (2 (The signal level corresponding to “1” of the value signal) and output to the flag signal generator 52. In the other part of FIG. 3, the output of the second average luminance level calculation unit does not exceed the threshold th1, so the comparison determination unit 51 sets the comparison determination signal to “0” (“0” of the binary signal). The signal level corresponding to “)” is output to the flag signal generator 52.

The flag signal generation unit 52 receives the comparison determination signal output from the comparison determination unit 51, and when the comparison determination signal is “1” as shown in FIG. Is determined to be affected by an external flash, and a flag signal for specifying the frame is output. In the case of FIG. 3, the flag signal generator 52 outputs a flag signal in the portion A. Therefore, in this case, the imaging signal specifying state detection device 100 specifies that the (n + 3) frame is a frame affected by the external flash, and the (n + 2) frame one frame before that is also affected by the external flash. It becomes possible to judge that it is.
As described above, in the imaging signal specific state detection device 100, the white belt-like interference due to the external flash occurs in the frame in which the flag signal is output and the frame one frame before the flag signal output from the determination unit 5. Can be identified.

Needless to say, the output signal of the comparison / determination unit 51 may be used as a flag signal.
Based on the flag signal output from the flag signal generation unit 52, the signal correction unit 6 identifies a frame that is affected by the external flash. Then, the signal correction unit 6 performs the signal for the frame affected by the external flash with respect to the imaging signal corresponding to the frame affected by the external flash (the imaging signal output from the imaging unit 1). A correction process is performed, and a signal correction process for a frame that is not affected by an external flash is performed on an image signal corresponding to a frame that is not affected by an external flash (an imaging signal output from the imaging unit 1). Do.
In addition, since the imaging signal specific state detection device 100 can appropriately know the frame position where the white belt-like interference has occurred, the correction signal unit 6 performs the white belt-like interference as shown in FIG. Various processes such as processing to remove and replace with other frame signals, or processing to convert to a signal at the time of flash shooting (when shooting in an environment with an external flash) similar to the case of an image pickup apparatus using a CCD type image pickup device Needless to say, the correction process can be easily executed.

[Second Embodiment]
<2.1: Configuration of Imaging Signal Specific State Detection Device 200>
FIG. 4 is a block diagram illustrating a configuration of the imaging signal specific state detection device 200 according to the second embodiment of the present invention.
The difference between the imaging signal specific state detection device 200 of the present embodiment and the imaging signal specific state detection device 100 of the first embodiment is that the second memory that newly stores the output signal of the second average luminance level calculation unit 4. The determination unit 11 outputs a determination signal based on the output signal of the second average luminance level calculation unit 4 and the output signal of the second storage unit 10. Other parts are the same as those in the first embodiment, and the same components are denoted by the same reference numerals, and detailed description thereof is omitted.

FIG. 5 is a block diagram illustrating an example of an internal configuration of the determination unit 11.
As illustrated in FIG. 5, the determination unit 11 includes a difference calculation unit 111 and a flag signal generation unit 112.
The difference calculation unit 111 receives the output signal of the second average luminance level calculation unit 4 and the output signal of the second storage unit 10, takes a difference between the two signals, and uses the difference signal as a difference signal. This is output to the flag signal generator 112.
The flag signal generation unit 112 generates a flag signal from the difference signal output from the difference calculation unit 111 when a total of three frames including the current frame signal and the previous two frame signals are in a specific pattern. Output.
<2.2: Operation of Imaging Signal Specific State Detection Device 200>
About operation | movement of the imaging signal specific state detection apparatus 200 comprised as mentioned above, FIG. 6 (a)-(g), FIG. 7 (a)-(g), FIG. 8 (a)-(g) is also used. The details will be described below.

FIGS. 6A to 6G, FIGS. 7A to 7G, and FIGS. 8A to 8G are parts (a) to (g) of the present embodiment shown in FIGS. It is a signal waveform diagram which shows the signal waveform of.
(2.2.1: Operation in the case shown in FIG. 6)
Similar to the first embodiment, when shooting is performed by the imaging signal specific state detection device 200 in an environment where an external flash has occurred, an image (external flash) is formed from an imaging signal output from the imaging unit 1 ( In the frame image, as shown in FIG. 6A, it is assumed that white belt-like interference occurs in, for example, the (n + 2) frame and the (n + 3) frame. The other frames are not particularly illustrated, but are assumed to be frames (frames that are not affected by the external flash) in which all the frames are captured with a uniform brightness.
At this time, the output signal of the first average luminance level calculation unit 2 is as shown in FIG. Since the output signal of the first average luminance level calculation unit 2 is an average luminance level for each frame, the first average luminance level (first average luminance level calculation unit) in a white band-like (n + 3) frame having a large disturbance. 2) is a large value.

Next, since the output signal of the first storage unit 3 is a signal delayed by one frame by receiving and storing the output signal of the first average luminance level calculation unit 2, an output as shown in FIG. Signal.
Since the output signal of the second average luminance level calculation unit 4 receives the output signals of the first average luminance level calculation unit 2 and the first storage unit 3 and calculates the average value of these signals, FIG. Output signal. That is, the output signal of the second average luminance level calculation unit 4 is a signal obtained by averaging two frames of the current frame (processing target frame) and the signal one frame before, and as a result, flash photography ( Even if the white belt-like obstruction caused by the external flash) extends over two frames, the luminance level average value for the two frames is likely to be larger than the luminance level average value for any other two frames.

The output signal of the second storage unit 10 receives the output signal of the second average luminance level calculation unit 4 and stores it in the same manner as the first storage unit 3 so that the input signal to the second storage unit 10 is one frame. Delay. That is, the signal output from the second storage unit 10 is a signal delayed by one frame with respect to the signal input to the second storage unit 10. Therefore, the output signal from the second storage unit 10 is a signal as shown in FIG.
The determination unit 11 receives the output signal of the second average luminance level calculation unit 4 and the output signal of the second storage unit 10 and detects white belt-like interference due to the flash (external flash). For example, as shown in FIG. 5, the determination unit 11 includes a difference calculation unit 111 and a flag signal generation unit 112 that receives the output signal (g) and outputs a flag signal. The difference calculation unit 111 acquires the difference signal by subtracting the output signal (e) of the second storage unit 10 from the output signal (d) of the second average luminance level calculation unit 4. The difference signal acquired by the difference calculation unit 111 is a signal as shown in FIG. In the case shown in FIG. 6, a large positive difference signal is acquired in a frame with a large white band interference of (n + 3) frames, and in a (n + 2) frame that is a frame with a small white band interference with respect to the imaging signal of the previous frame, A positive difference signal is acquired, and a negative difference signal is acquired in the (n + 4) frame, which is a frame one frame after the (n + 3) frame. That is, the sign of the difference signal “one frame before the current frame” is C (n + 2) (n is an integer), the sign of the difference signal of “current frame” is C (n + 3), and the sign of “one frame after the current frame” is When the sign of the difference signal is C (n + 4),
C (n + 2) → “Plus”,
C (n + 3) → “plus”,
C (n + 4) → “minus”,
In this case, it can be determined that the (n + 3) frame that is the current frame and the (n + 2) frame that is one frame before the current frame are affected by the external flash.

  The flag signal generation unit 112 detects a differential signal pattern (a pattern of a change in the sign of the differential signal). The flag signal generation unit 112, in three consecutive frames, the pattern of the difference signal is the above pattern, that is, a pattern in which “plus”, “plus”, “minus” (hereinafter, this pattern is referred to as “external flashlight detection code” 6), the flag signal shown in FIG. 6 (f) is output at the position of the frame where the difference signal is minus (the sign of the difference signal is minus). Then, the difference signal acquired by the difference calculation unit 111 in other frames has a difference signal level of “0” or “0” unless the state (signal level) of the subject signal (imaging signal) changes significantly. It becomes a small positive signal level close to “0” or a small negative signal level close to “0”. Therefore, the imaging signal specific state detection device 200 can easily detect the pattern in the difference signal. As a result, in the imaging signal specific state detection device 200, it is easy to find a white belt-like disturbance frame (a frame affected by an external flash).

If the absolute value of the signal level of the difference signal is smaller than the predetermined threshold th2, the flag signal generation unit 112 increases the detection accuracy of the frame affected by the external flash. The level may be regarded as “0”, the code of the difference signal may be set to “none”, and may be excluded from the determination target whether or not it matches the external flash detection code pattern. That is, in the flag signal generation unit 112, when the signal level of the differential signal in n frames is Diff (n) (n is an integer) and the absolute value thereof is abs (Diff (n)), the following (1) to (1) to When all of (3) are satisfied, it may be determined that the (n + 2) frame and the (n + 3) frame are affected by the external flash.
(1) abs (Diff (n + 2))> th2 and Diff (n + 2)> 0
(2) abs (Diff (n + 3))> th2 and Diff (n + 3)> 0
(3) abs (Diff (n + 4))> th2 and Diff (n + 4) <0
The above determination example is an example, and another method may be used. In the above, the determination by the sign is performed using the primary difference value. For example, the determination is made by a method using the secondary difference value (for example, a method of comparing the secondary difference value with a predetermined threshold value). Processing may be performed.

(2.2.2: Operation in the case shown in FIG. 7)
Next, the operation of the imaging signal specific state detection device 200 in the case shown in FIG. 7 will be described.
When an image is taken by the imaging signal specific state detection device 100 in an environment where an external flash is generated, an image (frame image) formed by the imaging signal output from the imaging unit 1 by the external flash is shown in FIG. FIG. 7B to FIG. 7G show the operation of each part when a white belt-like disturbance having a pattern as shown in FIG.
FIG. 7 shows FIGS. 4 and 5 in the case where a white belt-like disturbance of the same level (a white belt is divided into two frames in almost half the screen) occurs in the (n + 2) frame and the (n + 3) frame. The signal waveform of each part (a)-(g) of the imaging signal specific state detection apparatus 200 is shown.
The output signal (g) of the difference calculation unit 111 in this case is, as shown in FIG. 7 (g), a pattern in which a minus difference signal of the equivalent level is output after the plus signal of the equivalent level continues for two frames. Become.

The flag signal generator 112 detects the pattern of the difference signal and outputs the flag signal shown in FIG. 7F at the position of the frame where the difference signal is negative. Also in this case, the difference signal output from the difference calculation unit 111 in other frames is the level of the difference signal “0” unless the state (signal level) of the subject signal (imaging signal) changes significantly. , A small positive signal level close to “0” or a small negative signal level close to “0”. Therefore, the imaging signal specific state detection device 200 can easily detect the pattern in the difference signal. As a result, in the imaging signal specific state detection device 200, it is easy to find a white belt-like disturbance frame.
(2.2.3: Operation in the case shown in FIG. 8)
Next, the operation of the imaging signal specific state detection apparatus 200 in the case shown in FIG. 8 will be described.

When an image is taken by the imaging signal specific state detection device 200 in an environment where an external flash is generated, an image (frame image) formed by an imaging signal output from the imaging unit 1 by the external flash is shown in FIG. FIG. 8B to FIG. 8G show the operation of each part when a white belt-like disturbance having a pattern as shown in FIG.
FIG. 8 shows each part of the imaging signal specific state detection device 200 shown in FIGS. 4 and 5 when a large white belt-like interference occurs in the (n + 2) frame and a small white belt-like interference occurs in the (n + 3) frame. The signal waveforms of (a) to (g) are shown.
In this case, as shown in FIG. 8G, the output signal (g) of the difference calculation unit 111 outputs a positive difference signal after a large positive difference signal, and then a large negative difference signal. It becomes a pattern.

The flag signal generator 112 detects the pattern of the difference signal, and outputs the flag signal shown in FIG. 8F at the position of the frame where the difference signal is negative. Also in this case, the difference signal output from the difference calculation unit 111 in other frames is the level of the difference signal “0” unless the state (signal level) of the subject signal (imaging signal) changes significantly. , A small positive signal level close to “0” or a small negative signal level close to “0”. Therefore, the imaging signal specific state detection device 200 can easily detect the pattern in the difference signal. As a result, in the imaging signal specific state detection device 200, it is easy to find a white belt-like disturbance frame.
As described above, in the imaging signal specific state detection device 200 according to the present embodiment, the frame in which the flag signal is generated ((n + 4 in FIGS. 6 to 8) is detected by detecting the flag signal in various white belt-like interference patterns. Flash photography (external light) in the previous frame (corresponding to the (n + 3) frame in FIGS. 6 to 8) and the previous frame (corresponding to the (n + 2) frame in FIGS. 6 to 8)) It is possible to easily identify the occurrence of white band interference caused by a flash.

In the above description, three typical patterns (three patterns shown in FIGS. 6 to 8) are output as flag signal output examples. However, the pattern between them (intermediate pattern) also has a large difference signal. If characteristics such as a plus signal and a large minus signal are used as determination criteria, the imaging signal specifying state detection device 200 of the present embodiment is similar to the case of the three patterns described above, and similarly, the external signal flashes by a flag signal. Needless to say, it is possible to appropriately detect frames affected by the above.
Further, in the imaging signal specific state detection device 200 of the present embodiment, in the case of the pattern as shown in FIG. 8, it is possible to detect even a pattern that is difficult to detect in the first embodiment. It is possible to identify a frame in which band-like interference has occurred.
In addition, since the imaging signal specific state detection device 100 can appropriately know the frame position where the white belt-like interference occurs, the correction signal unit 6 performs, for example, as shown in FIG. As shown in the figure, a process for removing white-band interference and replacing it with another frame signal, or during flash shooting (when shooting in an environment with an external flash) similar to the case of an imaging device using a CCD type imaging device It goes without saying that various correction processes such as a process of converting into a signal can be easily executed.

[Other Embodiments]
In the imaging signal specific state detection device described in the above embodiment, each block may be individually made into one chip by a semiconductor device such as an LSI, or may be made into one chip so as to include a part or all of the blocks. Also good.
Note that the name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.
Further, the method of circuit integration is not limited to LSI, and implementation with a dedicated circuit or a general-purpose processor is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used.

Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. Biotechnology can be applied as a possibility.
Moreover, each process of the said embodiment may be implement | achieved by hardware, and may be implement | achieved by software. Further, it may be realized by mixed processing of software and hardware. Needless to say, when the imaging signal specific state detection device according to the above-described embodiment is realized by hardware, it is necessary to perform timing adjustment for performing each process. In the above embodiment, for convenience of explanation, details of timing adjustment of various signals generated in actual hardware design are omitted.
The specific configuration of the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the scope of the invention.

  An imaging signal specific state detection device, an imaging signal specific state detection method, a program, and an integrated circuit according to the present invention are used in an imaging device using a CMOS type imaging device that has recently been used in a video camera. The frame signal in which white band-like interference that occurs when a flash or the like is thrown can be detected with high accuracy, and an imaging device for a video camera using a CMOS image sensor, or an editing device that handles an imaging signal, It can be widely applied to storage devices and the like.

DESCRIPTION OF SYMBOLS 100, 200 Image pick-up signal specific state detection apparatus 1 Imaging part 2 1st average brightness level calculation part 3 1st memory | storage part 4 2nd average brightness level calculation part 5,11 Determination part 10 2nd memory | storage part 51 Comparison determination part 52,112 Flag signal generator 112 Difference calculator

Claims (11)

An imaging unit that converts light from the subject into an electrical signal and acquires it as an imaging signal;
A first average luminance level calculation unit for obtaining a first average luminance level that is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage unit capable of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit, two frames are obtained. A second average luminance level calculation unit for calculating an average luminance level for two frames that is an average luminance level of
A determination unit that determines a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for two frames calculated by the second average luminance level calculation unit;
An imaging signal specific state detection device comprising: The determination unit
A comparison determination unit that compares the average luminance level of the two frames with a first threshold value and outputs information indicating a comparison result;
Based on the information indicating the comparison result output from the comparison determination unit, when it is determined that the average luminance level for the two frames exceeds the first threshold, the current frame that is the processing target frame A flag signal generating unit for generating a flag signal indicating that the current frame is affected by an external flash in a frame one frame before,
Having
The imaging signal specific state detection apparatus according to claim 1. An imaging unit that converts light from the subject into an electrical signal and acquires it as an imaging signal;
A first average luminance level calculation unit for obtaining a first average luminance level that is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage unit capable of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit, two frames are obtained. A second average luminance level calculation unit for calculating an average luminance level for two frames that is an average luminance level of
The average luminance level for the second frame calculated by the second average luminance level calculation unit is stored, and the average luminance level for two frames stored after being delayed by a predetermined time is output as an average luminance level for two delayed frames. A second storage unit capable of
The average luminance level for two frames calculated by the second average luminance level calculating unit, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage unit, And a determination unit that determines a specific state of the imaging signal acquired by the imaging unit, based on
An imaging signal specific state detection device comprising: The determination unit
A difference calculation unit for obtaining a difference signal by subtracting the average luminance level for two delayed frames from the average luminance level for two frames;
The average luminance level for the two frames is set to L, the average luminance level for the two delayed frames is set to DL, the difference signal acquired by the difference calculation unit is set to Diff, and the current frame as the processing target frame is the Nth frame ( N is an integer)
(1) In the (N-2) th frame, which is a frame two frames before the Nth frame,
L-DL> th (th is a number satisfying th ≧ 0)
And satisfy
(2) In the (N−1) th frame, which is a frame one frame before the Nth frame,
L-DL> th (th is a number satisfying th ≧ 0)
And satisfy
(3) In the Nth frame,
L-DL <-th (th is a number satisfying th ≧ 0)
When satisfying, in the (N-1) th frame and the (N-2) th frame, a flag signal generating unit that generates a flag signal indicating that it is affected by an external flash,
Having
The imaging signal specific state detection apparatus according to claim 3.   An imaging device provided with the imaging signal specific state detection device according to claim 1. An imaging signal specific state detection method used in an imaging signal specific state detection apparatus including an imaging unit that converts light from a subject into an electrical signal and acquires the signal as an imaging signal,
A first average luminance level calculating step for obtaining a first average luminance level which is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage step of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame by the first storing step, two frames are obtained. A second average luminance level calculating step of calculating an average luminance level for two frames, which is an average luminance level of
A determination step of determining a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for the two frames calculated in the second average luminance level calculating step;
An imaging signal specific state detection method comprising: A program for causing a computer to execute an imaging signal specific state detection method used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and acquires the image as an imaging signal.
A first average luminance level calculating step for obtaining a first average luminance level which is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage step of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame by the first storing step, two frames are obtained. A second average luminance level calculating step of calculating an average luminance level for two frames, which is an average luminance level of
A determination step of determining a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for the two frames calculated in the second average luminance level calculating step;
A program for causing a computer to execute an imaging signal specific state detection method. An integrated circuit used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and obtains it as an imaging signal,
A first average luminance level calculation unit for obtaining a first average luminance level that is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage unit capable of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit, two frames are obtained. A second average luminance level calculation unit for calculating an average luminance level for two frames that is an average luminance level of
A determination unit that determines a specific state of the imaging signal acquired by the imaging unit based on the average luminance level for two frames calculated by the second average luminance level calculation unit;
An integrated circuit comprising: An imaging signal specific state detection method used in an imaging signal specific state detection apparatus including an imaging unit that converts light from a subject into an electrical signal and acquires the signal as an imaging signal,
A first average luminance level calculating step for obtaining a first average luminance level which is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage step of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame by the first storing step, two frames are obtained. A second average luminance level calculating step of calculating an average luminance level for two frames, which is an average luminance level of
The average luminance level for the second frame calculated in the second average luminance level calculating step is stored, and the average luminance level for two frames stored after being delayed by a predetermined time is output as an average luminance level for two delayed frames. A second storage step capable of:
The average luminance level for two frames calculated in the second average luminance level calculating step, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage step. And a determination step of determining a specific state of the imaging signal acquired by the imaging unit, based on
An imaging signal specific state detection method comprising: A program for causing a computer to execute an imaging signal specific state detection method used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and acquires the image as an imaging signal.
A first average luminance level calculating step for obtaining a first average luminance level which is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage step of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame by the first storing step, two frames are obtained. A second average luminance level calculating step of calculating an average luminance level for two frames, which is an average luminance level of
The average luminance level for the second frame calculated in the second average luminance level calculating step is stored, and the average luminance level for two frames stored after being delayed by a predetermined time is output as an average luminance level for two delayed frames. A second storage step capable of:
The average luminance level for two frames calculated in the second average luminance level calculating step, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage step. And a determination step of determining a specific state of the imaging signal acquired by the imaging unit, based on
A program for causing a computer to execute an imaging signal specific state detection method. An integrated circuit used in an imaging signal specific state detection device including an imaging unit that converts light from a subject into an electrical signal and obtains it as an imaging signal,
A first average luminance level calculation unit for obtaining a first average luminance level that is an average luminance level of a captured image for one frame formed by the imaging signal acquired by the imaging unit;
A first storage unit capable of storing the first average luminance level and outputting the first luminance level stored after being delayed for a predetermined time as a delayed first average luminance level;
By performing an averaging process on the first average luminance level and the delayed first average luminance level output after being delayed by a time corresponding to one frame from the first storage unit, two frames are obtained. A second average luminance level calculation unit for calculating an average luminance level for two frames that is an average luminance level of
The average luminance level for the second frame calculated by the second average luminance level calculation unit is stored, and the average luminance level for two frames stored after being delayed by a predetermined time is output as an average luminance level for two delayed frames. A second storage unit capable of
The average luminance level for two frames calculated by the second average luminance level calculating unit, and the average luminance level for two delayed frames output after being delayed by a time corresponding to one frame from the second storage unit, And a determination unit that determines a specific state of the imaging signal acquired by the imaging unit, based on
An integrated circuit comprising:

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