JP6753787B2 - Imaging device - Google Patents

Description

The present invention relates to an imaging device.

In order to reduce the burden of camera operation by a photographer, an invention of an auto iris control system that automatically controls the iris of a lens so that the brightness level becomes constant has been disclosed (for example, Patent Document 1).
Conventionally, detection is performed based on a specific screen area, such as center-weighted metering that detects the detection area for keeping the brightness level constant at the center of the screen and split metering that divides the screen into multiple blocks. .. In recent years, an invention of an auto iris control system for selecting a person or pet in a subject with a touch panel or the like and controlling the iris so that the brightness level of the object becomes constant has been disclosed (for example, Patent Document 3). ).

On the other hand, the television camera also has a function of correcting a specific hue for each pixel of 6 colors (see Patent Document 2). As an application, it detects the specific hue of a color that is easy for the viewer to pay attention to, such as the blue of a tennis court or the green of a soccer ground, such as a sports broadcast, and determines the brightness of a specific hue of a color that is easy for the viewer to pay attention to. An invention that makes it constant is disclosed (for example, Patent Document 4).

However, in sports broadcasting, even if the brightness of a specific hue of a color that is easy for the viewer to pay attention to, such as the blue of a tennis court or the green of a soccer ground where sunlight and lighting are dominant, is constant, the angle of view and the blue sky Since the brightness level of the dark part of the subject such as the audience seats under the roof fluctuates due to changes in clouds, etc., the operator keeps moving the pedestal (master black) level in the relay vehicle throughout the broadcast.

Japanese Unexamined Patent Publication No. 8-181907 Japanese Unexamined Patent Publication No. 9-247701 Japanese Unexamined Patent Publication No. 2009-01069 Patent Registration No. 5921761

An object of the present invention is to prevent the brightness level of a dark subject from fluctuating as compared with a tennis court or a field having a specific hue such as an attic or an under-roof spectator seat in a sports broadcast or the like.

The image pickup apparatus of the present invention is an image pickup apparatus having a brightness level control means for controlling exposure such as a lens iris or an amplification degree or an electronic shutter so that the brightness level of the video signal becomes constant, and is within a predetermined range of the video signal. Luminance level detecting means for detecting the brightness level of a predetermined color tone, dark area peripheral brightness level detecting means for detecting the brightness level around a dark part of a predetermined color tone whose brightness level is lower than the detected brightness level in a predetermined range, and pedestal. It has a pedestal level adjusting means for adjusting the level, and the pedestal level adjusting means is characterized in that the pedestal level adjusting means adjusts to keep the peripheral luminance level constant according to the luminance level detected by the luminance level detecting means.
That is, the present invention is an imaging device that automatically controls the exposure of a lens iris or amplification degree or electronic shutter so that the brightness level of a video signal becomes constant, and is darker than a tennis court or ground or track or field. Alternatively, a means for detecting fluctuations in the dark area brightness level (in the first range) of a subject with a hue (hue and saturation) in the first range (hue and saturation) such as the audience seats in the sun, and a pedestal (master black) level. It has a means to change it, and even if the angle of view changes, even if the sunlight (natural light) such as blue sky or white clouds or sunset changes, or even if the light other than the main lighting changes The video signal so that the brightness level (of the first range) of a subject with a first specific range (hue and saturation) of hue, such as a darker roof or a shaded audience seat, is constant. The pedestal (master black) level is changed by the opposite of the change in the brightness level (in the first range) of the subject with the hue (hue and saturation) in the first range (hue and saturation) such as the roof of the roof or the audience seat in the shade. It is an image pickup apparatus characterized in that

Further, the image pickup apparatus of the present invention is an image pickup apparatus having a luminance level control means for controlling an exposure such as a lens iris or an amplification degree or an electronic shutter so that the luminance level of the image signal becomes constant, and the image signal is the first. A high-luminance level fluctuation detecting means for detecting a high-luminance level fluctuation of a predetermined color tone in a predetermined range of 1, and a brightness around a dark portion of a predetermined color tone having a low luminance level as compared with a high-luminance level in a second predetermined range of a video signal. It has a dark area peripheral brightness level fluctuation detecting means for detecting level fluctuations and a pedestal level adjusting means for adjusting the pedestal level, and the pedestal level adjusting means has fluctuations in the high brightness level fluctuation detecting means and the dark area peripheral brightness level fluctuation detecting means. When interlocked, it is characterized by making adjustments to keep the brightness level around the dark area constant.
That is, the present invention relates to a second image signal (blue sky, clouds, sunset, etc.) in an imaging device that automatically controls exposure such as a lens iris or an amplification degree or an electronic shutter so that the brightness level of the image signal becomes constant. Means for detecting (average) fluctuations in the (second range) highlight luminance level of a subject with a range of tones (in hue and saturation) and a darker roof compared to a tennis court or ground or track or field, etc. Alternatively, a means for detecting fluctuations in the dark area brightness level (in the first range) of a subject with a color tone (in hue and saturation) in the first range such as the audience seats in the sun, and a pedestal (master black) level. Fluctuations in the (second range) highlight luminance level average of the subject (in the hue and saturation) in the second range (such as blue sky or clouds or sunset) of the video signal having means to fluctuate When the fluctuation of the dark area brightness level (in the first range) of the subject of the color tone (hue and saturation) in the first range (such as the audience seat of the sun shade) is linked, the dark area brightness level It is an imaging device characterized in that the pedestal (master black) level is changed so that the average becomes constant.

Further, the imaging device of the present invention further includes a luminance level average detecting means for detecting the average of the luminance levels of a predetermined hue in a third predetermined range of the video signal, and the luminance level controlling means is from the luminance level average detecting means. It is preferable to control the output brightness level to be constant. Alternatively, it has a peak detecting means for detecting an RGB level peak of a predetermined hue in a third predetermined range of a video signal, and the peak level controlling means controls the peak level output from the peak detecting means to be constant. Is also good.
That is, the present invention provides a means for detecting the average luminance level of a third specific hue region that the viewer can easily pay attention to, such as the blue color of a tennis court or the green color of a soccer field, in the image pickup apparatus (shaded audience seat). It has a means for detecting the average brightness level of a third specific hue region that is easy for the viewer to pay attention to (or the back of a roof, etc.), and keeps the average brightness level of the third specific hue region constant. It is an image pickup apparatus characterized in that the exposure of a lens iris or an amplification degree or an electronic shutter is automatically controlled so as to be. Alternatively, the image pickup apparatus detects an RGB level peak of a predetermined hue in a third predetermined range of a video signal in a third specific hue region that is easy for the viewer to pay attention to, such as blue of a tennis court or green of a soccer field. An image pickup apparatus having a peak detecting means for automatically controlling exposure of a lens iris, an amplification degree, an electronic shutter, or the like so that the peak level of the RGB level of the third specific hue region becomes constant. Is.

Further, it is preferable that the image pickup apparatus of the present invention further includes a setting menu and an image display unit for displaying a predetermined hue region within a predetermined hue, and the image display unit can select a predetermined hue region within the predetermined hue.
That is, the present invention has an image display unit for displaying a setting menu such as a viewfinder or a monitor display and an arbitrary hue region within the specific hue in the image pickup apparatus, and the specific hue is displayed on the image display unit. It is an image pickup apparatus characterized in that an arbitrary hue region within a hue is selected.

According to the present invention, it is possible to prevent the brightness level of a dark part of a subject such as a shaded audience seat or the back of a roof from fluctuating due to a change in the brightness of a bright sky such as a blue sky, white clouds or a sunset.

It is a block diagram which shows one Example of the image pickup apparatus of this invention. It is a block diagram which shows another Example of the image pickup apparatus of this invention. It is a schematic diagram which shows the magnitude relation of R / G / B and the corresponding hue range. It is a block diagram which shows the structure of the color tone correction part which is one Example of this invention. It is explanatory drawing of the hue region in the color tone correction of one Example of this invention. It is a conceptual diagram of the hue region of one Example of this invention. It is explanatory drawing of the calculation principle of the primary color component, the complementary color component and the saturation component of one Example of this invention. It is explanatory drawing of the bright sky and dark peripheral part determination correction of one Example of this invention. It is a correction characteristic diagram of one Example of this invention. It is a flowchart of pedestal level correction of one Example of this invention. It is explanatory drawing of the hue region in one Example of this invention and the conventional color tone correction. It is a conceptual diagram of one Example of this invention and the conventional hue region. It is explanatory drawing of one Example of this invention and the calculation principle of the conventional primary color component and complementary color component. It is one Example of this invention and the conventional hue correction characteristic figure. It is a schematic diagram which shows one Example of this invention and the operation of the conventional 6-color independent color tone correction. It is a flowchart which shows one Example of this invention and the operation of the conventional independent color tone correction.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1A is a block diagram showing an embodiment of the image pickup apparatus of the present invention, and includes a sky and dark peripheral portion determination correction section in a pre-gamma matrix using a prism and three image pickup elements.
In FIG. 1A, the image pickup apparatus includes a television camera 30, a lens 31, and an image display unit 40 such as a monitor display or a viewfinder.

The television camera 30 includes a prism (color separation optical system) unit 32, an image sensor unit 33R, 33G, 33B, a video signal processing unit 35 with a sky / dark peripheral region determination correction function, and a parallel-serial conversion unit (P / S). It is composed of 37 and a CPU (Central Processing Unit) 39.
The video signal processing unit 35 with a sky / dark peripheral portion determination correction function is composed of a sky / dark peripheral portion determination correction unit 38 and a matrix conversion unit (MATRIX) 36.
The sky and dark peripheral area determination correction unit 38 is composed of addition units 12, 13, 14, a gamma correction unit 381, and a color tone correction unit 382.
The image sensor units 33R, 33G, and 33B are CCD (Charge Coupled Device) (charge-coupled device) + AFE (analog front-end processor) or CMOS (Complementary Metal Oxide Semiconductor) image sensor.

In FIG. 1A, the incident light from the subject is imaged by the lens unit 31, and the imaged incident light is decomposed into red light, green light, and blue light by the prism (color separation optical system) unit 32.
The image sensor unit 33R photoelectrically converts red light into an R (Red) signal. The image sensor unit 33G photoelectrically converts green light into a G (Green) signal. The image sensor unit 33B photoelectrically converts a blue light B (Blue) signal.

The photoelectrically converted R / G / B signals are correlated internally when the image sensor units 33R, 33G, and 33B are CCDs, and internally when the image sensor units 33R, 33G, and 33B are CMOS image sensors. It performs heavy sampling, gain correction, and analog-to-digital conversion, and is sent to the video signal processing unit 35 with a sky and dark peripheral area judgment correction function to perform various video signal processing such as color tone correction, contour correction, gamma correction, and knee correction. Will be done.

FIG. 1B is a block diagram showing another embodiment of the image pickup apparatus of the present invention, and includes a sky and dark peripheral portion determination correction section in a post-gamma matrix using an image pickup device with an on-chip color filter.
In FIG. 1B, the image pickup apparatus includes a television camera 300, a lens 31, a monitor display, or a viewfinder 40.

The television camera 300 includes a prism (color separation optical system) unit 32, an image sensor unit 34, a video signal processing unit 350 with a sky / dark peripheral area determination correction function, a parallel-serial conversion unit (P / S) 37, and a CPU 39. It is configured.
The video signal processing unit 350 with a sky / dark peripheral portion determination correction function is composed of a sky / dark peripheral portion determination correction unit 380 and a matrix conversion unit (MATRIX) 36.
The sky and dark peripheral portion determination correction unit 380 is composed of addition units 12, 13, 14, a gamma correction unit 381, a color tone correction unit 382, and a color separation unit 383.
The image sensor unit 34 is a CCD image sensor with an on-chip color filter and a CMOS image sensor with an AFE or an AFE with an on-chip color filter.

In FIG. 1B, the incident light from the subject is imaged by the lens unit 31, and the imaged incident light is photoelectrically converted into, for example, an RGGB signal by the image sensor unit 34.
The photoelectrically converted RGGB signal is subjected to correlation double sampling, gain correction, and analog-to-digital conversion internally when the image sensor unit 34 is a CCD and internally when the image sensor unit 34 is a CMOS image sensor. Output to the color separator 383.
The color separation unit 383 color-separates the RGGB signal into an R signal, a G signal, and a B signal, and outputs the RGGB signal to the gamma correction unit 381. The gamma correction unit 381 performs gamma correction on the R signal, G signal, and B signal, and outputs the gamma correction to the color tone correction unit 382 and the like. The color tone correction unit 382 performs various video signal processing such as color tone correction, contour correction, and knee correction.

The imaging devices of FIGS. 1A and 1B control the exposure of the lens iris, the amplification degree, the electronic shutter, or the like so that the brightness level of the output video signal becomes constant.
Details will be described later, but in FIGS. 1A and 1B, hue determination of bright sky (blue sky, white clouds, sunset) and dark peripheral parts (shaded spectators' seats and the backside of the roof), peak level detection of bright sky, and dark peripheral parts Bottom level detection and pedestal (master black) level correction level calculation and correction.

After various video signal processing is performed in the signal processing units 35 and 350 with the sky and dark peripheral area judgment correction function, the output of the video signal of BT.709 is Y = 0.2126R + 0.7152G + 0.0722B.
Pb = 0.5389 (BY)
Pr = 0.6350 (RY)
R / G / B is converted into a luminance signal (Y) and a color difference signal (Pb / Pr) according to the calculation formula of. Then, it is converted into a serial video signal by the parallel-serial conversion unit (P / S) 37 and output to the outside.

In addition, the output of the video signal in ITU / BT.2020 with a wider color gamut than the primary color point of BT.709 Y = 0.2627R + 0.6780G + 0.0593B
Pb = 0.5315 (BY)
Pr = 0.6782 (RY)
There is also a video signal output of.
Furthermore, there is also an output of a video signal of the primary colors of red, green and blue.

The CPU (Central Processing Unit) 39 controls each part of the television camera 30. Further, the image display unit 40 of the viewfinder or the monitor display displays a setting menu of the image pickup apparatus or an arbitrary hue saturation region within the specific hue.

FIG. 3 is a block diagram showing a configuration of a color tone correction unit according to an embodiment of the present invention.
The color tone correction unit 382 is a block diagram showing the configuration of the sky and dark peripheral area determination and the dark peripheral area correction calculation unit according to the embodiment of the present invention, and is a block diagram showing a bright sky (blue sky, white clouds, sunset) and a dark peripheral area (shade). Hue determination of the audience seats and the back side of the roof) Shows the detailed configuration that realizes the peak level detection of the bright sky, the bottom level detection of the dark peripheral part, and the correction level calculation of the pedestal (master black) level. The color tone correction unit of FIG. 3 includes a configuration of color tone correction independent for each hue as in the conventional case.

FIG. 2 shows the magnitude relationship of R / G / B and the corresponding hue range. Here, the hue is displayed in 6 divisions, but if the magnitude relationship of each signal level of R / G / B is further subdivided, 12 colors are independent, 16 colors are independent, 18 colors are independent, 24 colors are independent, etc. It is also possible to redifferentiate the hue more.

The CPU 39 outputs information in an arbitrary hue range set by the user to the sky and dark peripheral area determination correction units 38 and 380 in the video signal processing units 35 and 350 with the sky and dark peripheral area determination correction function.
The sky and dark peripheral area determination correction units 38 and 380 in the video signal processing units 35 and 350 with the sky and dark peripheral area determination correction function output area information matching the hue range set by the user to the CPU 39.

Based on the area information, the CPU 39 gates the luminance signal from the matrix conversion unit (MATRIX) 36 in the video signal processing unit 35 with the sky / dark peripheral area determination correction function, and is in an arbitrary hue range set by the user. The iris of the lens 31 or the amplification degree of the image sensor units 33R, 33G, 33B or the exposure of the electronic shutter or the like is controlled so that the luminance signal level of the area becomes an arbitrary level set by the user. If the set hue range area deviates from the subject, exposure control such as iris, amplification degree, or electronic shutter is stopped (preserves the previous state) until the hue range area reenters the subject. ).

The image display unit 40 superimposes the menu screen on the image of the subject. The user sets the hue range and the luminance signal level while looking at the menu screen.
In addition, in order to confirm whether the hue range set by the user matches the color of the target subject, the area of the portion that matches the set hue range is superimposed on the subject image of the image display unit 40. Markers may be displayed.

As described above, according to the present invention, by controlling the lens iris so that the luminance signal level in an arbitrary hue range set by the user becomes constant, the brightness of the blue of the tennis court, the green of the soccer ground, etc. Can be automatically constant.

Next, the operation of the present invention will be described with reference to FIGS. 3 to 8.
In the color tone correction unit 382 of FIG. 3, the RGB arithmetic comparison unit 1 calculates and compares the magnitude of the color difference signal RG, and the GB arithmetic comparer 2 calculates and compares the magnitude of the color difference signal GB. , BR calculation comparer 3 performs calculation and magnitude comparison of the color difference signal BR, and outputs each calculation comparison result to the hue region determination unit (primary colors R, G, B, complementary colors Ye, Cy, Mg) 4 and chromaticity. Output to the degree component / primary color component / complementary color component determination unit 5.

The hue region determination unit (primary colors R, G, B, complementary colors Ye, Cy, Mg) 4 determines the hue region shown in FIG.
FIG. 5 is a conceptual diagram of a hue region, which is divided into six hue regions by using a straight line extending from the center point in each color direction as a reference line.

Further, the hue region determination unit 4 compares the signal levels of the R signal, the G signal, and the B signal, and determines the maximum level, the intermediate level, and the minimum level as shown in FIG. Then, in the process of this comparison determination, the level difference between the maximum level and the intermediate level is obtained and used as the primary color component amount, and further, the level difference between the intermediate level and the minimum level is obtained and used as the complementary color component amount. Here, the maximum level color corresponds to the primary color, and the minimum level component corresponds to the white component. Then, the complementary color can be determined from the information of the maximum level color and the minimum level color, and as a result, the primary color component and the complementary color component can be determined as shown in FIG.

In one example of FIG. 6, since the maximum level is R and the intermediate level is G, the primary color component is R and the complementary color component is Ye (yellow), which is an intermediate hue between R and G. The primary color component amount is RG, the complementary color component amount is GB, and the minimum level B amount is the white component amount. Therefore, in the case of FIG. 8, the result shown is the second from the bottom of FIG.
The determination result of the hue region by the hue region determination unit 4 is supplied to the constant selection unit 6, a specific gain constant is selected according to the determination result, and the saturation component is supplied to the multiplication units 7 and 8. The correction is performed by multiplying the amount of the primary color component and the amount of the complementary color component calculated by the / primary color component / complementary color component determination unit 5, respectively. Therefore, a specific gain constant corresponding to each hue region from the region 1 to the region 6 is set in the constant selection unit 6 in advance.

The primary color component amount and the complement color component amount obtained by multiplying the gain constants by the multiplication units 7 and 8 are sent to the data selection addition unit 11 for performing addition / subtraction selection and connection selection for the video signals R, G, and B. Then, it is supplied directly, on the other hand, via the complement parts (-1 times multiplication part) 9 and 10, respectively. Then, after the addition destination is selected by the data selection addition circuit 11, the data is supplied to the addition units 12, 13 and 14, and is added to the video signal R, the video signal G, and the video signal B.

Therefore, when the color tone of the video signal R is corrected, for example, in the case of correction in the saturation direction, the primary color component amount RG is multiplied by a specific constant Kr and then added to the video signal R. At this time, if the ratio by the constant Kr is in the range of -1 to 1 times, the level difference between the intermediate level and the minimum level (complementary color component amount) and the minimum level amount (white component amount) can be increased even by this correction. It does not change.

Further, when correcting the saturation direction of the signal Ye, the complementary color component amount GB is multiplied by a specific constant Ky and then added to R and G, respectively. Also at this time, if the ratio by the constant Ky is in the range of -1 to 1 times, even with this correction, the level difference between the maximum level and the intermediate level (primary color component amount) and the minimum level amount (white component amount) Does not change.

Therefore, in this case, by manipulating the constants Kr and Ky, it is possible to independently correct the saturation directions of the primary color R and the complementary color Ye while maintaining the white balance. In the above 6-color independent color tone correction method, the chromaticity direction can be corrected independently, and even when the input video signal is in a different hue, the independent correction can be performed in the same manner. Is omitted.

FIG. 10 is an explanatory diagram of an embodiment of the present invention and a hue region in a conventional color tone correction, FIG. 11 is a conceptual diagram of an embodiment of the present invention and a conventional hue region, and FIG. 12 is a diagram of the present invention. It is explanatory drawing of the calculation principle of an Example and a conventional primary color component and a complementary color component, FIG. 13 is an Example of this invention and a conventional hue correction characteristic diagram, and FIG. 14 is an Example of this invention and the conventional It is a schematic diagram which shows the operation of 6-color independent hue correction, and FIG. 15 is the flowchart which shows the operation of one Example of this invention and the conventional independent hue correction.
Since FIGS. 10 to 15 are the same as those of Japanese Patent Application Laid-Open No. 9-247701 of Patent Document 2, detailed description thereof will be omitted.

Next, the detailed operation of the image pickup apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1A, 1B, 3, 7, 7, 9, and 15.
FIG. 7 is a schematic view of a bright sky and a dark peripheral portion detection correction according to an embodiment of the present invention.
As an embodiment of the present invention, FIGS. 1A and 1B have functions of peak level detection of a bright sky, bottom level detection of a dark peripheral portion, and correction level calculation correction of a pedestal (master black) level.
Further, FIG. 15 is a flowchart showing an embodiment of the present invention and a conventional operation of independent color tone correction, and a hue is determined as shown in FIG.

FIG. 3 is a block diagram showing a configuration of a color tone correction unit according to an embodiment of the present invention. For example, a bright sky (blue sky, white clouds, sunset) and a dark peripheral portion (shade spectator seats and the back side of a roof). A detailed configuration that realizes hue determination, peak level detection in a bright sky, bottom level detection in a dark peripheral area, and correction level calculation correction for a pedestal (master black) level is shown. The color tone correction unit of FIG. 3 includes a configuration of color tone correction independent for each hue as in the conventional case.

In FIG. 3, the peak level detection of the bright sky, the bottom level detection of the dark peripheral portion, and the correction level calculation of the pedestal (master black) level are performed by the gate unit 41, the excessive signal deletion unit 42, the peak detection unit 43, and the gate unit 15. This is performed by the under signal deletion unit 18 and the bottom detection unit 19.
The peak level of the bright sky and the bottom level of the dark peripheral portion are sent to the CPU 39 of FIG. 1A or FIG. 1B, and the pedestal (master black) correction level is sent from the CPU 39 to the data selection addition unit 11.
The pedestal correction level may be sent to a pedestal (master black) correction unit (not shown) to correct the pedestal (master black) level.

In FIG. 3, the difference from the conventional color temperature detection is that the hue region determination signal is input to the gate portions of 41 and 15, and the level is detected (calculated) from the RGB signal of the determined hue.
For the RGB signals of the determined bright sky (blue sky, white clouds, sunset), the excessive signal deletion unit 42 deletes the excessive signal, and the peak detection unit 43 detects the peak level.
For the RGB signal in the determined peripheral portion (the audience seat in the shade or the back side of the roof), the under-signal deletion unit 18 deletes the under-signal, and the bottom detection unit 19 detects (calculates) the bottom level.
The peak level may be detected by the peak detection unit 43 from the RGB signal of the determined hue, and the CPU 39 may control the iris of the lens 31 or the amplification degree of the image sensor units 33R, 33G, 33B or the exposure of the electronic shutter or the like.

FIG. 7 is a schematic diagram of a bright sky and a dark peripheral area detection correction according to an embodiment of the present invention, in which (a) is a reference state of a G video signal, and the brightness of a tennis court is constant with auto iris or amplification degree or It controls the exposure of electronic shutters and the like. (b) is the G video signal: When the bright sky becomes a little darker and the dark surroundings become darker, the pedestal (master black) level is corrected. (c) This is a G video signal, and when the bright sky becomes bright and the dark surroundings become a little bright, the pedestal (master black) level is corrected. (d) is a G video signal, and when the bright sky becomes brighter and the dark surroundings become darker, the pedestal (master black) level is not corrected. (e) is a G video signal, and when the bright sky becomes a little dark and the dark surroundings become a little bright, the pedestal (master black) level is not corrected.

FIG. 9 is a flowchart of pedestal level correction according to an embodiment of the present invention.
In FIG. 9, the CPU 9 starts the correction process from “start” and calculates the level of the bright sky and the level of the dark periphery in FIG. 7 of the schematic diagram of “bright sky and dark peripheral area detection correction” according to the embodiment of the present invention. (S91), if the judgment of "the level of the bright sky is constant or rises" (S92) is YES, the judgment of "the level of the dark surroundings rises" (S93) is made, and if NO, the judgment of "the level of the dark surroundings is high". Go to the determination (S95) of "going up or constant".

If the judgment (S93) of "the level around the dark area rises" is YES, the CPU 9 executes "raise the pedestal (master black) level" (S94), and if NO, "does not correct the pedestal (master black) level". Execute (S96).
If the determination (S95) of "the level around the dark area rises or is constant" is YES, the CPU 9 executes "do not correct the pedestal (master black) level" (S96), and if NO, sets the "pedestal (master black) level". "Lower" is corrected (S97).
The CPU 9 then ends the correction process with "end".

That is, the common concept of the embodiments of the present invention is a tennis court or ground or track or field in an imaging device that automatically controls exposure such as lens iris or amplification degree or electronic shutter so that the brightness level of the video signal becomes constant. A means for detecting fluctuations in the dark area brightness level (in the first range) of a subject with a color tone (in hue and saturation) in the first range (hue and saturation), such as an audience seat under the roof or a darker roof than the above, and a pedestal. (Master black) It has a means to change the level, and even if the angle of view changes, even if the blue sky or clouds or light other than the main lighting such as sunset (natural light) changes, the tennis court or ground of the video signal. Or, the brightness level (of the first range) of a subject with a color tone (of hue and saturation) of the first specific range such as an audience seat under the roof or a darker roof than a truck or a field is fixed. As described above, the pedestal (of the first range) is the opposite of the change in the brightness level (of the first range) of the subject of the first range (hue and saturation) such as the spectator seat under the roof or the roof of the video signal. Master black) This is an imaging device characterized by varying the level.

Further, the specific hue highlight and the specific hue dark portion of the embodiment of the present invention are limited to the image pickup device that automatically controls the exposure of the lens iris or the amplification degree or the electronic shutter so that the brightness level of the video signal becomes constant. As a means of detecting (average) fluctuations in the (second range) highlight luminance level of a subject with a second range (hue and saturation) of hue (such as blue sky or clouds or sunset) of a video signal. Dark area brightness level (of the first range) of a subject with a first range (hue and saturation) such as a spectator seat under the roof or a darker roof than a tennis court or ground or track or field, etc. It has a means to detect fluctuations and a means to change the pedestal (master black) level, and is a subject of a second range (hue and saturation) of the video signal (blue sky or clouds or sunset, etc.). Fluctuations in the average brightness level of highlights (in the second range) and dark areas (in the first range) of the subject in the first range (of hue and saturation) of the first range (such as the audience seats under the roof). The imaging device is characterized in that the pedestal (master black) level is changed so that the average of the dark area brightness levels becomes constant when the fluctuation of the brightness level is linked.

Further, in the above image pickup apparatus, a means for detecting the average luminance level of a third specific hue region that is easy for the viewer to pay attention to, such as the blue color of the tennis court or the green color of the soccer field, and a means (such as a chair in the audience seat under the roof). The lens iris has a means for detecting the average brightness level of the third specific hue region that is easy for the viewer to pay attention to, and keeps the average brightness level of the third specific hue region constant. Alternatively, it is an imaging device characterized in that the degree of amplification or the exposure of an electronic shutter or the like is automatically controlled. Alternatively, the image pickup apparatus detects an RGB level peak of a predetermined hue in a third predetermined range of a video signal in a third specific hue region that is easy for the viewer to pay attention to, such as blue of a tennis court or green of a soccer field. An image pickup apparatus having a peak detecting means for automatically controlling exposure of a lens iris, an amplification degree, an electronic shutter, or the like so that the peak level of the RGB level of the third specific hue region becomes constant. Is.

Further, the image pickup apparatus has an image display unit for displaying a setting menu such as a viewfinder or a monitor display and an arbitrary hue region within the specific hue, and the image display unit has an image display unit within the specific hue. It is an image pickup apparatus characterized in that an arbitrary hue region is selected.

The imaging device according to the embodiment of the present invention can prevent the brightness level of a dark part of a subject such as a shaded audience seat or the back of a roof from fluctuating due to a change in the brightness of a bright sky such as a blue sky, white clouds, or a sunset. it can.

As a result, in sports broadcasts such as outdoor tennis broadcasts, outdoor baseball broadcasts, rugby broadcasts, and soccer broadcasts, the imaging device of the present invention can be used to output a stable video signal by the assist function for constant dark areas. .. In addition, stable video signals can be output even in surveillance applications such as High Dynamic Range.

Although one embodiment of the present invention has been described in detail above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

By detecting the interlocking of the high brightness fluctuation of a specific hue and the brightness fluctuation of a dark part of a specific hue, a subject dark part such as a shaded audience seat or the back of a roof due to a change in the brightness of a bright sky such as a blue sky, white clouds or sunset. It can be applied to applications that prevent fluctuations in the brightness level of.

1,2,3: Arithmetic / comparer, 4: Hue region determination unit, 5: Saturation component amount / primary color component amount / complementary color component amount determination unit, 6: Constant selection unit, 7,8: Multiplication unit, 9, 10: Complementary part (-1x multiplication part), 11: Data selection addition part, 12, 13, 14: Addition part, 16: Multiplication part, 30,300: Television camera, 31: Lens, 32: Prism (color) (Decomposition optical system), 33R, 33G, 33: Image pickup element section, 34: Image pickup element section, 35, 350: Sky and dark peripheral area determination correction function video signal processing section, 36: Matrix conversion section (MATRIX), 37: Parallel-serial conversion unit, 38,380: Sky and dark peripheral area judgment correction unit, 381: Gamma correction unit, 382: Hue correction unit, 383: Color separation unit, 39: CPU, 40: Image display unit, 41: Gate Unit, 42: Excess signal deletion unit, 43: Peak detection unit, 15: Gate unit, 18: Under signal deletion unit, 19: Bottom detection unit.

Claims (4)

In an imaging apparatus having a brightness level control means for controlling the exposure of a lens iris or an amplification degree or an electronic shutter so that the brightness level of a video signal becomes constant.
A luminance level detecting means for detecting a luminance level of a predetermined color tone in a predetermined range of the video signal, and a dark portion for detecting a luminance level around a dark portion of a predetermined color tone whose luminance level is lower than the detected luminance level in the predetermined range. It has a peripheral brightness level detecting means and a pedestal level adjusting means for adjusting the pedestal level.
The pedestal level adjusting means is an image pickup apparatus characterized in that the pedestal level adjusting means adjusts the brightness level around the dark portion to be constant according to the brightness level detected by the brightness level detecting means. In an imaging apparatus having a brightness level control means for controlling the exposure of a lens iris or an amplification degree or an electronic shutter so that the brightness level of a video signal becomes constant.
The brightness level is lower than that of the high-luminance level fluctuation detecting means for detecting the high-luminance level fluctuation of a predetermined color tone in the first predetermined range of the video signal and the high-luminance level in the second predetermined range of the video signal. It has a dark area peripheral brightness level fluctuation detecting means for detecting a brightness level fluctuation around a dark part of a predetermined color tone, and a pedestal level adjusting means for adjusting a pedestal level.
The pedestal level adjusting means is an imaging apparatus characterized in that when the fluctuations of the high brightness level fluctuation detecting means and the dark peripheral peripheral brightness level fluctuation detecting means are interlocked, the pedestal level adjusting means adjusts to keep the dark peripheral peripheral brightness level constant. .. In the imaging device according to claim 1 or 2.
Further, it has a luminance level average detecting means for detecting the average of the luminance levels of a predetermined hue in a third predetermined range of the video signal.
The luminance level control means controls the luminance level output from the luminance level average detecting means to be constant, or a peak that detects an RGB level peak of a predetermined hue in a third predetermined range of the video signal. An imaging device having a detecting means and one of controlling the peak level of the RGB level of the third specific hue region to be constant. In the imaging apparatus according to claim 1 to 3,
Further, it has an image display unit for displaying a setting menu and a predetermined hue area within a predetermined hue.
The image display unit is an image pickup apparatus characterized in that a predetermined hue region within the predetermined hue can be selected.

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