JPWO2016076396A1 - Imaging apparatus and imaging method - Google Patents

Abstract

An object of the present invention is to provide an imaging apparatus having lens magnification chromatic aberration that can be accurately corrected with a simple configuration. 16: 9 test chart with black border around the effective screen in an imaging device with a horizontal aspect ratio. Imaging signal at the border between the right and left effective screens and the black border, or the white and gray or black and gray border on the left and right of the grayscale chart Adjust the left-right balance of wide-angle chromatic aberration with the image pickup signal, and adjust the left-right balance of telephoto magnification chromatic aberration with the black image pickup signal on both sides of white in the center of the grayscale chart, or adjust the white balance at the center of the grayscale chart. The left / right balance of the chromatic aberration of super telephoto magnification is adjusted by the imaging signal.

Description

  The present invention relates to an imaging apparatus and an imaging method.

In general, a lens of an imaging device (television camera) that captures a color video signal has a refractive index that varies depending on the frequency of light, and a shift occurs in a position where an image is formed between light having a long wavelength and light having a short wavelength. Blur occurs in the video shot through the camera. In a color image composed of three primary colors of red (R, Red), green (G, Green), and blue (B, Blue), red having a longer wavelength and blue having a shorter wavelength are different from each other in a direction different from green. Therefore, for example, red or blue blurring occurs at the boundary between black and white. The amount of blur is proportional to the N (N is an integer) power of the distance from the center on the screen, and varies depending on lens parameters such as zoom, focus, and iris.
In general, the allowable chromatic aberration of a lens is about one pixel (one scanning line), so the ratio of the allowable chromatic aberration of the lens is the ratio of one pixel (one scanning line) to the image height, that is, the reciprocal of the number of effective scanning lines. It will be about.

As shown in FIG. 3 which is a schematic diagram of a change in the example of the chromatic aberration of magnification due to zooming of the zoom lens, the lateral chromatic aberration due to zoom changes individually in a nonlinear manner.
An image height circle is a circle centered on the center of the screen and having a diameter of the screen height (image height). In SDTV (Standard Definition TeleVision), the allowable chromatic aberration of a lens with an effective scanning line of about 486 to 576 is about 0.2% of pixels with respect to the image height, and HDTV (High Definition TeleVision) is effective scanning line. The allowable chromatic aberration of a lens with about 720 to 1080 is about 0.1%. In UHDTV (Ultra High Definition TeleVision), the allowable chromatic aberration of a lens with an effective scanning line of about 2160 is 0. If it is about 05% and about 4320, the allowable chromatic aberration of the lens is about 0.025%. In addition, expensive fluorite, low dispersion glass, and high refractive index glass may be used in combination to suppress chromatic aberration, and the zoom lens is generally larger and more expensive than the photographing apparatus main body.

  Therefore, the amount of deviation of the imaging position of red and blue light relative to green due to this chromatic aberration of magnification is obtained in advance for each pixel, and the deviation is corrected for the red and blue primary color signals of the photographed color video signal. Thus, a technique for correcting blurring of a video signal due to lateral chromatic aberration is disclosed (see Patent Document 1). In addition, a technique is disclosed in which a luminance signal and a color difference signal are converted into primary color signals of red, green, and blue, and distortion due to lens distortion and blur due to lateral chromatic aberration are corrected (see Patent Document 2).

  The inventions described in Patent Document 1 and Patent Document 2 can be realized when lens parameters such as zoom, focus, and iris are constant. On the other hand, when shooting a video signal (moving image) of a television program or the like with a camera, generally, it is often performed by changing lens parameters in various ways. In this case, in the inventions described in Patent Document 1 and Patent Document 2, if data indicating the amount of deviation of the imaging position corresponding to the change of the lens parameter is prepared in advance, it is difficult to acquire this data. In addition, a huge amount of data needs to be stored, which is not realistic.

  In order to solve this problem, for example, the invention described in Patent Document 3 has been proposed. The invention described in Patent Document 3 eliminates blurring of a color image due to chromatic aberration of magnification based on the lens parameter even when the lens parameter is changed to various values.

  However, the invention described in Patent Document 3 does not indicate an appropriate standard for the number of correction data stored in the storage unit. For this reason, the invention described in Patent Document 3 requires a large-capacity storage unit when the number of correction data is too large. On the other hand, the invention described in Patent Document 3 makes it difficult to select appropriate correction data if the number of correction data is too small, and the correction amount calculated using the correction data is significantly different from the actual shift amount of the video. Therefore, the correction cannot be performed accurately.

  In order to solve this problem, in order to provide a magnification chromatic aberration / image distortion correction device capable of accurate correction with a simpler configuration, the magnification chromatic aberration / image distortion correction device includes a correction data generation unit, correction data Correction data storage means for storing the correction data, a plurality of correction data are input, the number of correction data stored is calculated based on the storage capacity of the correction data storage means or a predetermined evaluation value, and the input correction data is stored Correction data thinning means to be written into the correction data storage means after thinning below, signal input means, lens parameter input means, correction data storage means, correction data selection means, correction amount calculation means, aberration correction means, A technique including a signal storage unit and a signal output unit is disclosed (see Patent Document 4).

Specifically, Patent Document 4 describes the value of a lens parameter of a camera that captures a video signal, the amount of image formation position shift due to chromatic aberration of magnification for each pixel of the image, and the amount of distortion of the image. A magnification chromatic aberration / image distortion correction apparatus that corrects at least one of color shift caused by the chromatic aberration of magnification and distortion of the video image using correction data that correlates at least one of the aberration amounts, and is a primary color. Correction data storage means for storing the correction data of the first primary color, the second primary color, and the third primary color, and a plurality of the correction data are input, and based on the storage capacity of the correction data storage means or a predetermined evaluation value The number of correction data stored is calculated, and the correction data between the correction data to be written to the correction data storage means after the input correction data is thinned below the stored number Subtracting means, signal input means for inputting the first primary color signal, the second primary color signal and the third primary color signal indicating the brightness of the first primary color, the second primary color and the third primary color for each pixel, and this signal Lens parameter input means for inputting photographing lens parameters corresponding to the pixels of the first primary color signal, the second primary color signal, and the third primary color signal inputted from the input means, which are lens parameters when photographing the video. And correction data selection means for selecting correction data of two lens parameters sandwiching the value of the photographing lens parameter stored in the correction data storage means on the basis of the photographing lens parameter input from the lens parameter input means And the magnification in the photographing lens parameter based on the correction data selected by the correction data selection means Based on a correction amount calculation means for interpolating and calculating a correction amount for correcting at least one of color misregistration due to aberration and distortion of the image, the first correction amount is calculated based on the correction amount calculated by the correction amount calculation means. Correction means for correcting the pixel values indicating the brightness of each pixel of the primary color signal, the second primary color signal, and the third primary color signal, and the first primary color signal, the second primary color signal, and the pixel values corrected by the correction means, And a chromatic aberration magnification / image distortion correction apparatus comprising: a signal output unit configured to output a third primary color signal.
That is, the invention described in Patent Document 4 that generates correction data, thins it below the stored number, stores it, inputs lens parameters, selects correction data, calculates a correction amount, and corrects the aberration of the signal. The structure and operation are still complicated and not suitable for miniaturization.

Further, in the imaging apparatus and method, the amount of chromatic aberration according to the distance from the reference position in the color image based on the color image signal output from the photoelectric conversion means is detected, and the amount according to the detected distance from the reference position is detected. A technique is disclosed in which predetermined signal processing for correcting chromatic aberration is performed on a color video signal based on the amount of aberration (see Patent Document 5).
However, the invention described in Patent Document 5 corrects chromatic aberration approximated by a cubic curve of distance for each focus position for each individual. That is, since the lens parameters such as zoom, extender, and iris are not taken into account, the accuracy of correcting the chromatic aberration of the zoom lens as shown in FIG. 3 in the schematic diagram of the change in the chromatic aberration of magnification due to the zoom of the zoom lens is still high enough. It is not possible to use a zoom lens with low cost and large chromatic aberration.

  Therefore, in the prior art, a zoom lens in which the optical axis adjustment of each lens constituting the zoom lens, which is called a ball push at a low price, is incomplete, cannot be used.

  In addition, the Institute of Image Information and Television Engineers (abbreviated as ITE, formerly known as The Institute of Television Engineers) has a black border around the white sides in the center. The effective dimensions of a 16: 9 type reflective chart such as a 16: 9 type gray scale chart with black are M: 192 x 108 mm, M: 320 x 180 mm, L: 512 x 288 mm, 16: 9 Dai Nippon Printing Co., Ltd. has an effective dimension of 512 × 288 mm for the reflective chart of the type.

JP-A-6-292207 JP 2000-3437 A JP 2006-135805 A JP 2011-182071 A JP 2000-299874 A

  The present invention eliminates the need for complicated settings, and has a simple configuration, called spherical push, with sufficiently high accuracy of chromatic aberration of magnification of a zoom lens in which the optical axis adjustment of each lens constituting the zoom lens is incomplete. An object of the present invention is to provide an imaging apparatus and an imaging method for correcting a color video signal that can be corrected.

  An imaging apparatus of the present invention is an imaging apparatus that outputs a color video signal having a lens that outputs magnification chromatic aberration characteristic information and an imaging element, and the present lens extender from a plurality of lens magnification chromatic aberration characteristics acquired from the lens, A means for calculating a correction formula for magnification chromatic aberration at each position of zoom, focus and iris, calculating a correction amount of magnification chromatic aberration in each area of the horizontal component of the screen obtained by dividing the video signal, and a predetermined test chart Means to detect the imaging signal at the border between the effective screen and black border or the white and gray or black and gray border at the left and right of the grayscale chart, and the left-right balance of the wide-angle magnification chromatic aberration with the detected border imaging signal Means for adjusting, means for detecting an imaging signal at the border between black on both sides of the white at the center of the gray scale chart and gray on the background; Means for adjusting the left-right balance of the chromatic aberration of telephoto with the image signal of the border, and means for detecting the image signal of the black boundary between the two ends of white at the center of the gray scale chart or the background gray, and imaging of the detected border And means for adjusting the left / right balance of the chromatic aberration of super-telephoto with a signal, and at least one of the means for adjusting.

  The image pickup apparatus of the present invention is the above-described image pickup apparatus, and adjusts the left / right balance of the lateral chromatic aberration, and is approximately half of the screen width corresponding to the photographing range at the closest distance between the telephoto end and the wide angle end of the zoom lens. Means for superimposing a marker on a viewfinder image or monitor image at a position; means for detecting an imaging signal at the boundary of the imaging signal of the marker portion; and means for adjusting the left-right balance of magnification chromatic aberration with the imaging signal at the detected boundary It is characterized by that.

  The image pickup apparatus of the present invention is the above-described image pickup apparatus, and the image pickup apparatus includes an image pickup unit, a transmission path, and a control unit, and the red image pickup signal and the blue image pickup signal are alternately displayed after the magnification chromatic aberration is corrected by the image pickup unit. In this case, the thinned green imaging signal is transmitted to the control unit using the transmission line without being thinned, and the red imaging signal and the blue imaging signal which are alternately thinned and transmitted in the control unit by the green imaging signal transmitted without being thinned. It is characterized by comprising means for interpolating, means for generating a video signal from a green image pickup signal transmitted without thinning out the interpolated red image pickup signal and blue image pickup signal, and means for outputting the generated image signal.

  The image pickup apparatus of the present invention is an image pickup apparatus that outputs a color video signal having a lens that outputs magnification chromatic aberration characteristic information and an image pickup element, and is based on a plurality of lens magnification chromatic aberration characteristics acquired from the lens. Means for calculating a correction equation for magnification chromatic aberration at each position of the extender, zoom, focus and iris, calculating a correction amount of magnification chromatic aberration in each region of the horizontal component of the screen obtained by dividing the video signal, and the image pickup device being an image pickup unit; And a transmission path and a control section, and after the chromatic aberration of magnification is corrected by the imaging section, the red imaging signal and the blue imaging signal are alternately thinned out, and the green imaging signal is transmitted to the control section using the transmission path without being thinned out. And the controller interpolates the red imaging signal and the blue imaging signal alternately transmitted by the thinning with the green imaging signal transmitted without the thinning, and the interpolation. And having means for generating a video signal by a green imaging signal transmitted without thinning out the color image signal and the blue image sensing signal, and means for outputting an image signal generated.

  An imaging method of the imaging apparatus of the present invention is an imaging method of an imaging apparatus that outputs a color video signal having a lens that outputs a plurality of magnification chromatic aberration characteristic information and an imaging element, and has a black border around the effective screen. A step of detecting an imaging signal at the border between the effective screens at the left and right ends of a certain 16: 9 test chart and a black border or an imaging signal at the border between white and gray or black and gray at the left and right of the gray scale chart, and an imaging signal at the detected border To adjust the left-right balance of wide-angle chromatic aberration at wide angle, to detect an image signal at the border between black on both sides of the white at the center of the gray scale chart and the gray at the background, and to detect the telephoto with the image signal at the detected border Adjusting the left / right balance of the lateral chromatic aberration of the image, and detecting the image signal at the boundary between the black at both ends of the center white of the gray scale chart or the background gray And adjusting the left and right balance of the super-telephoto magnification chromatic aberration in the imaging signal of the detected boundary, and having at least one adjustment step magnification chromatic aberration correction.

  The imaging method of the imaging apparatus according to the present invention is the imaging method of the imaging apparatus described above, and corresponds to the imaging range at the closest distance between the telephoto end and the wide-angle end of the zoom lens that adjusts the left / right balance of the chromatic aberration of magnification. The step of superimposing the marker on the viewfinder image or the monitor image at a position approximately half of the screen width, the step of detecting the imaging signal at the boundary of the imaging signal of the marker portion, and the left-right balance of the lateral chromatic aberration with the imaging signal of the detected boundary It is characterized by adjusting.

  According to the present invention, it is possible to correct the lateral chromatic aberration of a zoom lens called a spherical push with a simple configuration without the need for complicated settings.

1 is a block diagram illustrating a configuration of an imaging apparatus that corrects lateral chromatic aberration according to an embodiment of the present invention. FIG. It is a schematic diagram for demonstrating the area | region division | segmentation method of the screen with a magnification chromatic aberration of one Example of this invention. It is a schematic diagram of a magnification chromatic aberration characteristic example of an image height circle by zooming of a zoom lens. It is a schematic diagram of the optical axis adjustment of the left and right balance lens before and after correcting the chromatic aberration of magnification of the zoom lens. FIG. 6 is a schematic diagram of an example of imperfect adjustment of the optical axis of a zoom lens before and after correcting chromatic aberration of magnification and right and left balance lenses. It is a schematic diagram of the left-right balance adjustment of the example before and after the magnification chromatic aberration correction of the zoom lens of one Example of this invention, and the left-right balance lens optical axis adjustment incomplete example. It is a schematic diagram of the detection position of the magnification chromatic aberration by the zoom of a 16: 9 gray scale chart and a wide-angle zoom lens. 4 is a flowchart for correcting lateral chromatic aberration when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens according to the embodiment of the present invention. It is a flowchart which correct | amends the magnification chromatic aberration at the time of image-capturing a 16: 9 gray scale chart with the shortest object distance of the zoom lens of other one Example of this invention. It is a flowchart which shows the simple operation | movement of the gray scale auto setup of other one Example of this invention. It is a schematic diagram of the interpolation by G1G2 after RB thinning-out transmission of the imaging device comprised by the imaging part, the transmission path, and the control part. It is a schematic diagram of the video signal of interpolation using all the pixels of the RBG1G2 Bayer array four-plate image pickup device and the RBG1G2 Bayer array single-plate color body image pickup device. It is a block diagram which shows the structure of the image shift circuit which correct | amends the magnification chromatic aberration of other one Example of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
A configuration of an image pickup apparatus that corrects lateral chromatic aberration according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a block diagram showing the configuration of an image pickup apparatus that corrects lateral chromatic aberration according to an embodiment of the present invention.
In FIG. 1, an imaging device 119 such as a television camera includes an imaging unit 100, a transmission path 117, and a control unit 118.
Note that the image capturing unit 100 and the control unit 118 may be integrated without the transmission path 117.
In addition, the image pickup apparatus in FIG. 1 has a color separation optical system that generates RBG1G2 (Rch, Bch, G1ch, and G2ch) as an image pickup signal and a four-plate type image pickup apparatus that includes four image pickup elements or a Bayer array on-chip color array that includes RBG1G2. Although it is a single plate color image pickup device having an image pickup device with a filter, a three-plate type image pickup device including a color separation optical system that generates RGB (Rch, Gch, Bch) as an image pickup signal and three image pickup devices may be used.

The imaging unit 100 includes an imaging unit 108, a video signal processing unit 120, a CPU (Central Processing Unit) 121, and a VF (View Finder) unit 134.
The photographing unit 108 includes an optical system, an image sensor, and the like not shown.
The CPU 121 includes a lens data acquisition unit 102, a lens magnification chromatic aberration characteristic formula acquisition unit 103, a correction formula storage unit 104, a lens position data acquisition unit 105, each region correction amount calculation unit 106, and a correction amount output unit 107. A magnification chromatic aberration correction signal is generated and output from the lens information and lens data obtained from the above.
The video signal processing unit 120 includes an area correction amount storage unit 109, a vertical address 110, vertical correction amount switching units 111R and 111B, horizontal correction amount switching units 112R and 112B, vertical image shift units 113R and 113B, and a horizontal image shift unit 114R. , 114B, a horizontal address 116, a detection position marker generation unit 131, a synthesis unit 132, and a VF signal output unit 133.
The imaging unit 108 outputs Ri, Bi, G1i, and G2i image signals generated by photoelectrically converting incident light imaged by the lens 101 to the video signal processing unit 120.
The control unit 118 includes a video signal output unit including an interpolation function.

The imaging apparatus 100 acquires lens data from the lens 101 by the lens data acquisition unit 102. The lens data includes lens magnification chromatic aberration characteristic data and lens extender, zoom, focus, and iris position data.
Lens magnification chromatic aberration characteristic expression data is acquired by the lens magnification chromatic aberration characteristic expression acquisition unit 103 when the camera is started or when the lens is connected, and the correction chromatic aberration characteristic expression is stored as a correction expression based on an expression in which the magnification chromatic aberration characteristic expression is moved with respect to the axis of the distance from the lens center. Store in the unit 104.

The correction formula is a correction formula of the first or higher correction amount using the distance from the center of the lens as a parameter, and there are correction formulas for RG color difference and BG color difference, respectively.
The correction formula is associated with the iris position, focus position, zoom position, and extender state at each division point. The number of division points and the number of extender states differ depending on the lens.
Therefore, the lens data acquisition unit 102 is equal to or higher than the number of times obtained by multiplying the number of iris position division points, the number of focus position division points, the number of zoom position division points, the number of extender states, and the two color differences RG and BG. Get the correction formula. The correction formula storage unit 104 stores the correction formula.
The lens position data acquisition unit 105 acquires the current iris position, focus position, zoom position, and extender lens position by real-time processing because the lens position during camera operation changes according to the scene in the program. .

The current lens position acquired by the lens position data acquisition unit 105 is a continuous value position. However, since the correction formula stored in the correction formula storage unit is a correction formula at each division point of the discrete lens positions, the correction formula cannot be applied as it is.
Each area correction amount calculation unit 106 selects and reads out the correction formula stored in the correction formula storage unit 104 from the extender state of the current lens position. Then, each region correction amount calculation unit 106 calculates an RG correction formula and a BG correction formula for the current lens position by linear interpolation from correction formulas at division points near the iris position, focus position, and zoom position. To do. Since the correction formula is of the first order or higher, linear interpolation is performed for each coefficient.

Next, a region dividing method for obtaining the RG aberration correction amount and the RG aberration correction amount at the center address of each region of the video signal from the correction formula selected by each region correction amount calculation unit 106 will be described with reference to FIG. Will be described.
FIG. 2 is a schematic diagram for explaining a region dividing method for a screen having lateral chromatic aberration according to an embodiment of the present invention.
FIG. 2 shows that the screen is divided into 128 pixels in both the horizontal and vertical directions from the center of the screen, and each region has a correction amount.

Each region correction amount calculation unit 106 separates the correction amount into a vertical direction correction amount, a horizontal direction correction amount, and respective components from the aberration correction amount at the center address of each region and the center address of each region. This is performed for each region.
The correction amount output unit 107 outputs the calculated vertical direction correction amount and horizontal direction correction amount of each region.
Each region correction amount storage unit 109 of the video signal processing unit 120 stores the vertical direction correction amount and the horizontal direction correction amount of each region.

The video signal processing unit 120 receives Ri, Bi, G1i, and G2i image signals output from the imaging unit 108.
The vertical correction amount switching unit 111R selects the vertical direction correction amount output from each region correction amount storage unit 109 based on the address value output from the vertical address 110, and outputs it to the vertical image shift unit 113R.
The horizontal correction amount switching unit 112R selects the horizontal direction correction amount output from each area correction amount storage unit 109 based on the address value output from the horizontal address 116, and outputs the horizontal correction amount to the horizontal image shift unit 114R.
The vertical image shift unit 113R shifts the Ri image signal in the vertical direction based on the vertical direction correction amount output from the vertical correction amount switching unit 111R, and outputs it to the horizontal image shift unit 114R.
The horizontal image shift unit 114R shifts the vertically shifted Ri image signal in the horizontal direction based on the horizontal correction amount output from the horizontal correction amount switching unit 112R, and the horizontally shifted Rm image signal is the video signal output unit 115. Output to.

The vertical correction amount switching unit 111B selects the vertical direction correction amount output from each region correction amount storage unit 109 based on the address value output from the vertical address 110, and outputs it to the vertical image shift unit 113B.
The horizontal correction amount switching unit 112B selects the horizontal direction correction amount output from each region correction amount storage unit 109 based on the address value output from the horizontal address 116, and outputs it to the horizontal image shift unit 114B.
The vertical image shift unit 113B shifts the Bi image signal in the vertical direction based on the vertical direction correction amount output from the vertical correction amount switching unit 111B and outputs the Bi image signal to the horizontal image shift unit 114B.
The horizontal image shift unit 114B shifts the vertically shifted Bi image signal in the horizontal direction based on the horizontal correction amount output from the vertical correction amount switching unit 112B, and the horizontally shifted Bm image signal is the video signal output unit 115. Output to.
The image delay units 122 and 123 delay the G1i and G2i image signals so as to be in phase with the Ri and Bi image signals to be image shifted.

The lens data acquisition unit 102 also outputs the lens data acquired from the lens 101 to the detection position marker generation unit 131.
The detection position marker generation unit 131 generates a detection position marker at the wide-angle end corresponding to the type of lens detected based on the lens data output from the lens data acquisition unit 102 and outputs the detection position marker to the synthesis unit 122. The synthesizing unit 132 synthesizes the G1m image signal and the detection position marker, and outputs them to the VF signal output unit 133. The VF signal output unit 133 outputs a G1m image signal obtained by combining the detection position markers to the VF unit 134.
Note that the image signal to be combined with the detection position marker is not limited to the G1m image signal, and may be, for example, a Y signal generated from the Rm, Bm, G1m, and G2m image signals.

  The video signal output unit 115 of the control unit 118 performs processing such as gamma correction and detail on the Rm, Bm, G1m, and G2m image signals, and outputs the result as a video signal output.

In television cameras, even the extender state changes during operation, so each lens position is acquired in real-time processing, and high-precision chromatic aberration of magnification is obtained by using a correction formula for the chromatic aberration characteristic equation for each lens position. It is important to correct the video signal for correction.
Especially when using a zoom lens with an extender with low cost and large chromatic aberration for surveillance applications, each lens position is acquired in real-time processing, and a correction formula for the magnification chromatic aberration characteristic formula for each lens position is used. It is very important to perform video signal correction with high-accuracy magnification chromatic aberration correction suitable for miniaturization.

  The image pickup apparatus according to the embodiment of the present invention does not require complicated settings, and the zoom lens chromatic aberration, which varies depending on the lens parameters of the extender, zoom, focus, and iris, can be set with a simple configuration. Even if the chromatic aberration of magnification due to the zoom of the zoom lens as shown in FIG. 3 of the schematic diagram of the change of the chromatic aberration characteristic changes nonlinearly individually, the correction value interpolated from the correction equation by linear interpolation can be easily corrected with sufficient accuracy. Can be performed.

Example 1
Furthermore, the present invention is a flowchart for correcting chromatic aberration of magnification when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens of one embodiment of the present invention (lens information can be detected by serial I / O or the like). 6A in the case of adjusting the left / right balance of lateral chromatic aberration at the wide-angle end and the telephoto end of the zoom lens) and a 16: 9 gray scale chart with the shortest subject distance of the zoom lens of another embodiment of the present invention. Flowchart for correcting chromatic aberration of magnification when taking an image (Lens information cannot be detected by serial I / O, etc., and the left / right balance of chromatic aberration of magnification is manually adjusted between the focal length near the wide-angle end and the focal length near the telephoto end of the zoom lens. As shown in FIG. 6B.
Magnification chromatic aberration at each position of current lens extender, zoom, focus, and iris from multiple lens magnification chromatic aberration characteristics obtained from a lens that outputs magnification chromatic aberration characteristic information and an image sensor and outputs a color video signal And a means for calculating the correction amount of the lateral chromatic aberration of each area of the horizontal component of the screen obtained by dividing the video signal (there is a serial I / O, and a high-definition that performs gray scale setup when the lens is replaced (16: 9, 3: 2, etc.) of horizontal aspect ratio,
Even with a standard zoom lens capable of close-up photography, such as the closest subject distance of 0.56 m at the wide-angle end focal length of 7.6 mm and the closest subject range of 655 mm x 368 mm, the closest subject distance of 0.3 m at the wide-angle end focal length of 4.5 mm Even with a wide-angle zoom lens capable of close-up photography, such as 655 mm x 368 mm, even with a telephoto end focal length of 413 mm, the shortest subject distance of 2.2 m, and with a telephoto zoom lens such as the closest shooting range of 12.3 mm x 682 mm, the shortest with a telephoto end focal length of 164 mm 16: 9 (Dai Nippon Printing Co., Ltd.) with a black border around the effective screen (grayscale chart, registration chart, etc.) even with a standard zoom lens with a subject distance of 0.9 m and a closest shooting range of 982 mm x 552 mm Murakami Color Research Laboratory's 512mm x 288mm reflection type) Effective chart on both left and right test charts and black Means for detecting the imaging signal at the border, means for adjusting the left-right balance of the wide-angle magnification chromatic aberration with the detected border imaging signal, means for detecting the imaging signals at both ends of the center white of the rascale chart, and Means for adjusting the left-right balance of the chromatic aberration of super telephoto with the image signal of the detected border; and means for adjusting at least one of:
It is an imaging device which has.

In other words, FIG. 6A is a flowchart for correcting the chromatic aberration of magnification when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens of one embodiment of the present invention, and the lens information is serial I / O or the like. This is a case where the left / right balance of lateral chromatic aberration is adjusted between the wide-angle end and the telephoto end of the zoom lens.
FIG. 6B is a flowchart for correcting the chromatic aberration of magnification when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens according to another embodiment of the present invention, and the lens information is obtained by serial I / O or the like. This is a case where the left-right balance of lateral chromatic aberration is manually adjusted by the focal length near the wide-angle end and the focal length near the telephoto end of the zoom lens.

In addition, although the accuracy is reduced, for the sake of simplicity, even under the above conditions, means for detecting an imaging signal at the boundary between the left and right white and gray or the black and the background gray of the grayscale chart and the imaging signal at the detected boundary And means for adjusting the left-right balance of the wide-angle magnification chromatic aberration.
In the case of using a zoom lens having a wider angle, means for detecting an imaging signal at the boundary between black at both ends of the white at the center of the gray scale chart or gray at the background and the magnification chromatic aberration of the telephoto by the imaging signal at the detected boundary. It is an imaging device having means for adjusting the left-right balance.

Next, the operation of the imaging apparatus according to an embodiment of the present invention will be described with reference to FIG. 6A.
FIG. 6A is a flowchart for correcting lateral chromatic aberration when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens of one embodiment of the present invention.
This description of the operation is a case where lens information can be detected by serial I / O or the like, and the lateral balance of lateral chromatic aberration is adjusted at the wide-angle end and the telephoto end of the zoom lens.
In FIG. 6A, the imaging device 119 starts processing at start S60.
In the process of S61, the lens data acquisition unit 102 detects the lens type.
In the process of S62, the detection position marker generating unit 131 generates a detection position marker at the wide angle end corresponding to the detected lens type, and the combining unit 132 combines the detection position marker and the G1m image signal to generate a VF signal output unit 133. Is output to the VF unit 134 or a monitor (not shown), and the detection position marker synthesized by the VF unit 134 or the monitor with the G1m image signal is displayed.

In the process of S63, the imaging device 119 captures a 16: 9 grayscale chart in the vicinity of the closest distance of the lens so that the detection position marker at the wide-angle end is aligned with the left and right ends of the effective screen.
In the process of S64, the imaging device 119 determines whether or not the boundary between gray and black is captured at the detection position of the 16: 9 grayscale chart, and the boundary between gray and black is captured ( If YES, the process proceeds to S65, and if the border between gray and black is not captured (NO), the process returns to S62.
In the processing of S65, the magnification chromatic aberration correction is adjusted so that the imaging device 119 makes the phase of the red signal and the phase of the blue signal equal to the phase of the green signal after the magnification chromatic aberration correction at the boundary between gray and black.
In the process of S66, the adjustment amount of the magnification chromatic aberration correction adjusted by the imaging device 119 is set as the offset amount at the wide angle end, the central focal length is set as the offset amount “0”, and the intermediate focal length is linearly interpolated.

In the processing of S67, the detection position marker generating unit 131 generates a detection position marker at the wide-angle end corresponding to the detected lens type, and the combining unit 132 combines the detection position marker and the G1m image signal to generate a VF signal output unit 133. Is output to the VF unit 134 or a monitor (not shown), and the detection position marker synthesized by the VF unit 134 or the monitor with the G1m image signal is displayed.
In the process of S68, the imaging device 119 images the 16: 9 gray scale chart in the vicinity of the close distance of the lens so that the detection position marker at the wide angle end is aligned with the left and right ends of the effective screen.
In the process of S69, the imaging device 119 determines whether or not the boundary between gray and black is captured at the detection position of the 16: 9 grayscale chart, and the boundary between gray and black is captured ( If YES, the process proceeds to S70, and if the boundary between gray and black is not captured (NO), the process returns to S67.
In the processing of S70, the imaging device 119 adjusts the magnification chromatic aberration correction so that the phase of the red signal and the phase of the blue signal are equal to the phase of the green signal after the magnification chromatic aberration correction at the boundary between gray and black.
In the process of S71, the adjustment amount of the magnification chromatic aberration correction adjusted by the imaging device 119 is set as the offset amount at the telephoto end, the central focal length is set as the offset amount “0”, and the intermediate focal length is linearly interpolated.
The imaging device 119 ends the process in S72.

Next, the operation of the imaging apparatus according to another embodiment of the present invention will be described with reference to FIG. 6B.
FIG. 6B is a flowchart for correcting the chromatic aberration of magnification when a 16: 9 gray scale chart is imaged at the shortest subject distance of the zoom lens according to another embodiment of the present invention.
The flowchart of FIG. 6B shows a case where the lens information cannot be detected by serial I / O or the like, and the left / right balance of the lateral chromatic aberration is manually adjusted by the focal length near the wide-angle end and the focal length near the telephoto end of the zoom lens. is there.
In FIG. 6B, the imaging device 119 starts processing at start S60.
In the process of S81, the imaging device 119 acquires the lens type selected by the operation unit (not shown).
In the process of S82, the imaging device 119 generates a detection position marker at the wide-angle end corresponding to the selected lens type from the detection position marker generation unit 131, and the combining unit 132 combines the detection position marker with the G1m image signal. The detection position marker output from the VF signal output unit 133 to the VF unit 134 or a monitor (not shown) and combined with the G1m image signal by the VF unit 134 or the monitor is displayed.

In the process of S63, the imaging device 119 captures a 16: 9 grayscale chart in the vicinity of the closest distance of the lens so that the detection position marker at the wide-angle end is aligned with the left and right ends of the effective screen.
In the process of S64, the imaging device 119 determines whether or not the boundary between gray and black is captured at the detection position of the 16: 9 grayscale chart, and the boundary between gray and black is captured ( If YES, the process proceeds to S65. If the boundary between gray and black is not captured (NO), the process returns to S82.
In the processing of S65, the magnification chromatic aberration correction is adjusted so that the imaging device 119 makes the phase of the red signal and the phase of the blue signal equal to the phase of the green signal after the magnification chromatic aberration correction at the boundary between gray and black.
In the process of S66, the adjustment amount of the magnification chromatic aberration correction adjusted by the imaging device 119 is set as the offset amount at the wide angle end, the central focal length is set as the offset amount “0”, and the intermediate focal length is linearly interpolated.

In the process of S83, the detection position marker corresponding to the lens type selected by the imaging device 119 is generated from the detection position marker generation unit 131, and the combining unit 132 combines the detection position marker and the G1m image signal. The detection position marker output from the VF signal output unit 133 to the VF unit 134 or a monitor (not shown) and combined with the G1m image signal by the VF unit 134 or the monitor is displayed.
In the process of S68, the imaging device 119 images the 16: 9 gray scale chart in the vicinity of the close distance of the lens so that the detection position marker at the wide angle end is aligned with the left and right ends of the effective screen.
In the process of S69, the imaging device 119 determines whether or not the boundary between gray and black is captured at the detection position of the 16: 9 grayscale chart, and the boundary between gray and black is captured ( If YES, the process proceeds to S70, and if the boundary between gray and black is not captured (NO), the process returns to S83.
In the processing of S70, the imaging device 119 adjusts the magnification chromatic aberration correction so that the phase of the red signal and the phase of the blue signal are equal to the phase of the green signal after the magnification chromatic aberration correction at the boundary between gray and black.
In the process of S71, the adjustment amount of the magnification chromatic aberration correction adjusted by the imaging device 119 is set as the offset amount at the telephoto end, the central focal length is set as the offset amount “0”, and the intermediate focal length is linearly interpolated.
The imaging device 119 ends the process in S72.

Next, the operation of the imaging apparatus according to another embodiment of the present invention will be described with reference to FIG. 6C.
FIG. 6C is a flowchart showing a simple operation of gray scale auto setup according to another embodiment of the present invention.
Further, the accuracy is improved when the operations of FIGS. 6A and 6B are performed after adjusting the modulation shading, gamma, knee, and flare shown in the flowchart of FIG. 6C.

In FIG. 6C, the imaging device 119 starts the process at start S60.
In the process of S91, the imaging device 119 turns on forced auto iris and real-time auto white.
In the process of S92, the imaging device 119 displays the white and black detection position markers of the gray scale chart on the VF unit 134 or the monitor.
In the process of S93, the imaging device 119 performs standard imaging of the grayscale chart.
In the process of S94, it is determined whether the imaging device 119 is picked up at the detection position and the white level is 90% or more and the black level is 10% or less, and the white level is 90% or more and the black level is 10% or less. When the image is captured (YES), the process proceeds to S95. When the white level is 90% or more and the black level is not captured to 10% or less (NO), the process returns to S92.
In the process of S95, the imaging device 119 adjusts modulation shading, gamma, knee, and flare.
The imaging device 119 ends the process in S72.

  The imaging apparatus according to the embodiment of the present invention is not only a schematic diagram of the zoom lens of FIG. 4A before and after correcting the chromatic aberration of magnification and a right-and-left balance lens optical axis adjustment (ball push) complete example (correction amount appropriate for both left and right), 4B before and after magnification chromatic aberration correction and left and right balance lens optical axis adjustment (ball pressing) incomplete example (left is insufficient correction amount, right is excessive correction amount) left and right balance of magnification chromatic aberration correction FIG. 4C is a schematic diagram of the left and right balance adjustment of the zoom lens of the zoom lens according to the embodiment of the present invention shown in FIG. In both cases, the lateral chromatic aberration correction is appropriate for both left and right.

(Example 2)
Next, an imaging device configured with an imaging unit, a transmission path, and a control unit will be described.
FIG. 7 is a schematic diagram of interpolation by G1G2 after RB decimation transmission, and a schematic diagram of video signals for interpolation using all pixels of a four-plate imaging device with an RBG1G2 Bayer array and a single-plate color body imaging device with an RBG1G2 Bayer array. As shown in FIG. 8, in the image pickup apparatus according to the first embodiment, the image pickup apparatus includes an image pickup unit, a transmission path, and a control unit, and the red image pickup signal and the blue image pickup signal are corrected after the magnification chromatic aberration is corrected by the image pickup unit. And means for transmitting the image signal of the thinned green image to the control unit using the transmission path as it is without being thinned, and the red image signal and the blue image signal that are alternately thinned and transmitted by the control unit, Means for interpolating with the green imaging signal transmitted as it is without thinning, the Y and band of the luminance signal with the interpolated red imaging signal and blue imaging signal, and the green imaging signal transmitted as it is without thinning out Means for generating a video signal of PB and PR of a color difference signal of half Y, and means for outputting a video signal of PB and PR of a color difference signal Y of the generated luminance signal and half of the band Y. It is an imaging device characterized by having.
Even if a PB and PR video signal of a color difference signal with a half band Y is output, if chromatic aberration of magnification of two pixels or more corresponding to a frequency lower than the half Y band remains, it is noticeable. Therefore, in Example 2, after the magnification chromatic aberration is corrected by the imaging unit, the red imaging signal and the blue imaging signal are alternately thinned and transmitted, and the chromatic aberration of magnification of two pixels or more corresponding to a frequency lower than the half band of Y is transmitted. Do not generate.

Moreover, the imaging apparatus which is embodiment of this invention is comprised by the imaging part of FIG. 7, the transmission line, and the control part.
The image pickup device may be interpolated after the thinning transmission to obtain a color difference signal having a half band of the luminance signal as shown in the schematic diagram of the interpolation by G1G2 after the RB thinning transmission, or the four-plate imaging device of the RBG1G2 Bayer array in FIG. As shown in the schematic diagram of the interpolated video signal using all pixels with the RBG1G2 Bayer array single-plate color body imaging device, interpolation may be performed using all the pixels to obtain a color difference signal in the same band as the luminance signal.

(Example 3)
FIG. 9 is a block diagram showing a configuration of an image shift circuit for correcting lateral chromatic aberration according to another embodiment of the present invention.
1 is different from the image shift circuit in the block diagram showing the configuration of the imaging apparatus for correcting the chromatic aberration of magnification according to the embodiment of the present invention. FIG. 1 shifts the image vertically and horizontally, whereas FIG. Just shift the image. If the amount of lateral chromatic aberration is small on a horizontally long screen such as 16: 9, the image may be shifted horizontally as shown in FIG.

  In FIG. 9, 121 is a CPU unit, 124 is a screen position control unit including a horizontal pixel counter, 40 to 47 are adders, D0 to D7 are pixel delay units, and P10 to 18 are positive multipliers. It is. Reference numerals 122 and 123 denote image delay units, which delay the G1G2 image so that the phase of the image shifts to the RB image.

  The image pickup apparatus according to the embodiment of the present invention can correct the chromatic aberration of magnification of the zoom lens called “ball push” with high accuracy with a simple configuration without requiring complicated settings.

  Although the present invention has been described in detail above, it is needless to say that the present invention is not limited to the imaging apparatus described here, and can be widely applied to imaging apparatuses other than those described above.

  This application claims the benefit of priority based on Japanese Patent Application No. 2014-231459 filed on Nov. 14, 2014, the entire disclosure of which is incorporated herein by reference.

The present invention is applied to correction of chromatic aberration of magnification in a photographing apparatus that shoots a color video signal, and in particular, correction of video signal of high-precision magnification chromatic aberration correction suitable for miniaturization when using a zoom lens with an extender that is low in price and has large chromatic aberration. it can. In particular, because of the low price, it is possible to correct the chromatic aberration of magnification of a zoom lens, which is called spherical push, and the optical axis of each lens constituting the zoom lens is inadequately adjusted with sufficiently high accuracy. This makes it possible to correct fine color video signals.
Here, SDTV has a lens chromatic aberration of about 0.2% that is allowed with 486 to 576 effective scanning lines, and HDTV has a lens chromatic aberration that is allowed with about 720 to 1080 effective scanning lines. Is about 0.1%. In UHDTV, if the number of effective scanning lines is about 2160, the allowable chromatic aberration of the lens is about 0.05%, and if about 4320, the allowable chromatic aberration of the lens is 0.025%. Degree. In addition, the zoom lens is generally larger and more expensive than the photographing apparatus main body.
Therefore, in the present invention, when an SDTV zoom lens is used in an HDTV photographing apparatus, a chromatic aberration zoom lens for HDTV is used in a UHDTV photographing apparatus, or a zoom lens having about 2160 effective scanning lines is provided. The present invention can be applied to video signal correction of high-accuracy chromatic aberration correction suitable for downsizing in a wide range of applications such as when used in a photographing apparatus of a degree.

Also, the color shift at the upper and lower ends of the screen is usually not as noticeable as the center of the screen. However, if information such as earthquake bulletins, election bulletins, heavy rain flood warnings, etc. is inserted into the L-shape of the screen during monitoring or broadcasting, the upper and lower sides of the captured image moved inside the receiver with the L-shaped information The color shift at the edge becomes noticeable. Furthermore, for monitoring and broadcasting, the chromatic aberration of the lens becomes the largest. In addition to using the telephoto end frequently, an extender in which the chromatic aberration of the lens changes greatly during operation is turned on and off.
Therefore, the present invention can be applied to high-accuracy chromatic aberration correction video signal correction suitable for miniaturization in a wide range of applications such as when an HDTV or UHDTV photographing apparatus is used for monitoring or broadcasting.

DESCRIPTION OF SYMBOLS 100: Imaging part, 101: Lens, 102: Lens data acquisition part, 103: Lens magnification chromatic aberration characteristic formula acquisition part, 104: Correction formula storage part, 105: Lens position data acquisition part, 106: Each area | region correction amount calculation part, 107: correction amount output unit, 108: photographing unit, 109: area correction amount storage unit, 110: vertical address, 111R, 111B: vertical correction amount switching unit, 112R, 112B: horizontal correction amount switching unit, 113R, 113B: Vertical image shift unit, 114R, 114B: horizontal image shift unit, 115: video signal output unit, 116: horizontal address, 117: transmission path, 118: control unit, 119: imaging device, 120: video signal processing unit, 121: CPU, 122, 123: Image delay unit, 124: Screen position control unit, 131: Detection position marker generation unit, 132: Composition unit, 133 VF signal output unit, 134: VF unit, 40 to 47: adder, D0 to D7: pixel delay unit, P10～18: positive multiplier.

Claims (6)

In an imaging apparatus that outputs a color video signal having a lens and an imaging device that output chromatic aberration characteristic information of magnification,
A correction formula for magnification chromatic aberration at each position of the extender, zoom, focus, and iris of the current lens is obtained from a plurality of lens magnification chromatic aberration characteristics acquired from the lens, and the horizontal direction component of the screen is obtained by dividing the video signal into regions. Means for calculating a correction amount of lateral chromatic aberration;
Means for detecting an imaging signal at the border between the effective screens at the left and right ends of the predetermined test chart and the black border, or an imaging signal at the border between white and gray or black and gray on the left and right of the grayscale chart;
Means for adjusting the left-right balance of wide-angle chromatic aberration at the detected border imaging signal;
Means for detecting the imaging signal at the border between black on both sides of the white in the center of the gray scale chart and gray of the background, and means for adjusting the left-right balance of the lateral chromatic aberration of the telephoto by the imaging signal at the detected border;
Means for detecting an imaging signal at the boundary between black at both ends of white at the center of the gray scale chart or gray at the background, and means for adjusting the left-right balance of the chromatic aberration of super telephoto by the imaging signal at the detected boundary ,
An image pickup apparatus comprising at least one of the means for adjusting. The imaging device according to claim 1,
Means for adjusting the left / right balance of the chromatic aberration of magnification, and a means for superimposing a marker on the viewfinder image or the monitor image at a position approximately half from the screen width corresponding to the photographing range at the closest telephoto end and wide angle end of the zoom lens;
Means for detecting an imaging signal at the boundary of the imaging signal of the marker portion;
An image pickup apparatus comprising: means for adjusting a left / right balance of the lateral chromatic aberration using the image pickup signal at the detected boundary. In the imaging device according to claim 1 or 2,
The imaging device includes an imaging unit, a transmission path, and a control unit,
Means for transmitting the red imaging signal and the blue imaging signal alternately after the magnification chromatic aberration correction in the imaging unit to the control unit using the transmission path without thinning out the green imaging signal;
Means for interpolating the red imaging signal and the blue imaging signal alternately thinned and transmitted with the green imaging signal transmitted without the thinning in the control unit;
Means for generating a video signal from the interpolated red imaging signal and blue imaging signal and the green imaging signal transmitted without being thinned;
Means for outputting the generated video signal;
An imaging device comprising: In an imaging apparatus that outputs a color video signal having a lens and an imaging device that output chromatic aberration characteristic information of magnification,
A correction formula for magnification chromatic aberration at each position of the extender, zoom, focus, and iris of the current lens is obtained from a plurality of lens magnification chromatic aberration characteristics acquired from the lens, and the horizontal direction component of the screen is obtained by dividing the video signal into regions. Means for calculating a correction amount of lateral chromatic aberration;
The imaging device includes an imaging unit, a transmission path, and a control unit,
Means for transmitting the red imaging signal and the blue imaging signal alternately after the magnification chromatic aberration correction in the imaging unit to the control unit using the transmission path without thinning out the green imaging signal;
Means for interpolating the red imaging signal and the blue imaging signal alternately thinned and transmitted with the green imaging signal transmitted without the thinning in the control unit;
Means for generating a video signal from the interpolated red imaging signal and blue imaging signal and the green imaging signal transmitted without being thinned;
Means for outputting the generated video signal;
An imaging device comprising: In an imaging method of an imaging apparatus that has a lens that outputs a plurality of magnification chromatic aberration characteristic information and an imaging element and outputs a color video signal,
16: 9 test chart with black border around the effective screen The detection signal is detected by detecting an imaging signal at the border between the right and left effective screens and the black border, or a white and gray or black and gray border at the left and right of the gray scale chart. Adjusting the left-right balance of the wide-angle magnification chromatic aberration with the imaging signal at the border,
Detecting an imaging signal at the border between black on both sides of the white in the center of the grayscale chart and gray in the background;
Adjusting the left-right balance of telephoto lateral chromatic aberration with the image signal of the detected border;
Detecting an imaging signal at a boundary between black at both ends of white at the center of the gray scale chart or gray at the background;
Adjusting the left-right balance of super-telescopic chromatic aberration with the image signal of the detected border;
An imaging method for an imaging apparatus, comprising an adjustment step for correcting at least one magnification chromatic aberration. In the imaging method of the imaging device according to claim 5,
Adjusting the left / right balance of the chromatic aberration of magnification, superimposing a marker on the viewfinder image and the monitor image at a position approximately half of the screen width corresponding to the shooting range at the closest telephoto end and wide angle end of the zoom lens;
Detecting an imaging signal at the boundary of the imaging signal of the marker portion;
An image pickup method for an image pickup apparatus, wherein the left / right balance of the chromatic aberration of magnification is adjusted by an image pickup signal at the detected boundary.