JPS6189790A - Solid color image pick-up device - Google Patents

Abstract

PURPOSE:To execute registration correcting processing to respective chrominance components and to execute the high quality color image pick-up by executing substitute of the data based upon the said corrected data while corrected data formed previously are read from a memory means when the image-pick-up is actually operated. CONSTITUTION:When the image pick-up is actually operated, a control part 10 reads respective color registration corrected data Dcr, and Dcb from the corrected data memory 15 and 16, supplies through decoders 17 and 18 to regis tration correcting processing part 6 respectively and controls an action. Respec tive data delayed by delay circuits DLya, DLyb, DLxa, DLxb, DLxc, DLcd, DLcd, DLxe, and DLxf are selected by respective selector switches SWa and SWb controlled in accordance with control data (a) and (b) supplied from the control part 10, and the data, in which substitute processing is executed in the horizontal direction of the picture, are obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a charge coupled device (CCII) as an imager for photographing a subject.
The present invention relates to a solid-state color imaging device using a solid-state image sensor such as a device, and particularly to one in which an error in superimposition (so-called registration) of images of each color occurring in an imaging optical system or the like is corrected by electrical signal processing.

[Conventional techniques] Generally, television cameras for color shooting separate the subject image into three-color optical images of red, green, blue, and take pictures.
A color image is reproduced by overlapping images of each color. Therefore, each color's i! Since the overlay error of the i-image appears as color blurring in the reproduced color image, it is necessary to make it extremely small.

Conventionally, color television cameras using image pickup tubes
In order to eliminate errors in overlapping images, so-called registration adjustment is performed by mechanical position adjustment of each imaging surface and electrical adjustment of the deflection system. In addition, in a solid-state color television camera that uses a CCD* solid-state image sensor, the I
Since it is not possible to adjust the ll image area, mechanical registration adjustment has been performed with high precision. Furthermore, as a method for electrically checking the register storage of a solid-state color television camera, a technique for controlling the frequency of the driving pulse of a solid-state image sensor is disclosed in, for example, Japanese Patent Laid-Open No. 58-59690. has been done.

[Problems to be Solved by the Invention] In general, in a color imaging device, there is an overlay error, that is, a registration error, of images of each color due to the ratio aberration of the imaging optical system. Assuming that the overlay error due to the chromatic magnification aberration is zero at the center of the screen, the amount of error tends to increase as the distance from the center of the screen increases. Therefore, simply eliminating the overlay error at the center of the screen through mechanical registration adjustment will not result in -1-
There is a problem in that it is impossible to eliminate overlay errors caused by color magnification aberration.

In addition, in a solid-state color imaging device, if the frequency of the drive pulse of the solid-state image sensor is controlled to adjust the registration by 1T, the time axis of the imaging output read from the solid-state image sensor will fluctuate. There is a problem in that the signal t1 processing becomes difficult.

Therefore, one aspect of the present invention is to solve the problems of the conventional technology as described above.
Electrical signal processing of the imaging output from a solid-state image sensor enables high-level registration adjustment for overlay errors caused by aberrations.
The object of the present invention is to provide a solid-state color imaging device with a novel configuration that is capable of performing high-quality color imaging and is foldable.

[Means for Solving the Problem] In order to solve the problem described in L, Unexamined 11 is about each color signal obtained by capturing an image using color-separated imaging light of each color using a solid-state image sensor. ,) J#P becomes l
Detecting the difference between the color signal and other color signals, 1. A woman in one pixel of an image based on the color signal of memory! storage means for storing correction data formed by a neighborhood process of selecting a pixel of an image according to a color signal serving as a storage reference, in which a color signal serving as a reference reference is obtained that is closest to a corresponding color signal; a signal processing means for performing registration correction processing by selectively delaying the color signal stored in the upper memory and the color signal stored in the lower memory based on the correction data read from the storage means; It is characterized by a wait configuration.

[Function] The solid-state color imaging device according to the present invention selectively delays color signals based on the correction data while reading out the correction data formed in advance by neighborhood processing from the storage means during actual imaging operation. Registration correction processing is performed on each color signal by an electrical signal processing means that performs replacement processing.

[Embodiment] Hereinafter, an embodiment of the solid-state color imaging device according to the present invention will be described in detail with reference to the drawings.

The embodiment shown in the block diagram of FIG.
This is applied to a CD digital television camera, in which the imaging light from the subject passes from the imaging lens 1 to the color separation prism 2.
Three CCD image sensors 3R, 3G, and 3B that are guided and irradiated through the camera constitute an imaging unit 3 that takes T&I images of the subject.

In this embodiment, from the image lens l to the color separation prism 2 -1- the CCD image sensor 3
1-Imaging light guided to R, 3G, and 3B is.

1. By color separation prism 2! It is decomposed into primary color components, i.e., red light R1, green light G, and blue light B.
The image is formed on each imaging surface J- of the CD image sensors 3R, 3G, and 3B.

The imaging unit 3 captures optical images of the three primary color lights R, G, and H using the CCD image sensors 1-2 and 3R, respectively.

Photographing is performed at 3G and 3B, and Mihara's signals, that is, red signal Er, green signal Eg, and blue signal Eb are output as the photographic output. Then, the knee 1 obtained by the J-2 imaging section 3
! The 11 color signals Er, Eg, and Eb are sent to analog/digital 9 (A
/D) is supplied to the converter 5. 1- The A/D converter 5 converts the three primary color signals Er, Eg, and Eb into three A/D converters.
The data is digitized by D converters 5R15G and 5B to form each color data Dr, Dg, and Db. Each color data Dr, Dg obtained by this A/D converter 5.

Db is supplied to the process processing section 7 via the registration correction processing section 6, and the three process processing circuits 7R, 7G, and 7B of this process processing section 7 perform processes such as gamma correction and clamp processing. After the processing is performed, the data is converted into, for example, NTSC color image data Dout by a color encoder 8 and output from an output terminal 9.

Each color data Dr supplied from the A/D converter 5,
The registration correction processing unit 6 that performs registration correction processing on D g and D b uses the green signal Eg obtained by the CCD image sensor 3G for photographing a green optical image of the imaging unit 3 as a reference, and performs registration correction processing on the other images. red traffic light Er
The registration correction process is performed on the blue signal Eb and the blue signal Eb, and the A/D converter 5 digitizes 1-k=primary color signals Er, Eg, Eb into each color data Dr.
, I) g, Db, a delay circuit 6G that delays green data Dg by a predetermined interval, and two correction circuits 6R that perform correction processing on red data Dr and blue data Db.
- Consists of 6B.

In the registration correction processing section 6 of this embodiment, ■: recording color data D8 is set to ili! The above Wi to make Lf
! The circuit 6G has a pixel pitch P1. of the CCD image sensor which will be described later. il equivalent to P irises! The configuration is as shown in FIG. 2, in which delay circuits 6gy and 63m each having a length of extension are connected in series. ”-1ll of recorded color data Dg
i! By extending the phase advance time axis processing to n (enabled), red data Qr and n color data Db
The two correction circuits 6R and 6B that perform correction processing on the
The configuration is as shown in the figure. That is, the pixel pitch P of the CCD image sensor! Two 'M delay circuits DLya and DLyb having a 'M delay amount corresponding to
Six delay circuits D Lxa, D Lxb, D each having a delay amount corresponding to the pixel pitch PI of the D image sensor.
Lxc, D Led.

DLxe, DLxf, a 2-circuit 2-contact selector switch SWa that is controlled according to control data a given by the control unit IO as described later, and a 3-circuit 2-contact selector switch that is controlled according to control data b. switch SWb;
Two decoders DCa and DCb that determine the magnitudes of α and β indicated by control data c and d, and a two-circuit, two-contact selector switch SWc that is controlled according to the output of the first decoder DCa. , selector switches SWu and SWma of each circuit 2#1 point controlled according to the output of the second decoder DCb, and each of the above-mentioned selector switches SWu.
, an adder ADD that adds the outputs selected by the SW master.
It is composed of.

The A/D converter 5 also outputs the three primary color signals Er and E.
Each color data Dr, D obtained by digitizing g, Eb
g and Db are also supplied to a control unit IO for controlling the operation of the registration correction processing unit 6.

The control unit 1O described in F is provided with three image memories 11, 12, and 13 for storing each color data Dr, Dg, and Db supplied from the A/D conversion unit 5. The above image memory 11
．． In 12.13, the three primary color signals -jEr, Eg, and Eb obtained by photographing a predetermined test chart) TC by the Ltn image unit 3 during the registration adjustment operation are 1-A/A/
Each color data Dr, Dg, digitized by the D converter 5
Db is stored.

Further, the L number control unit 10 controls the 1-th image memory 11° 12
．． Based on each color data Dr, Dg, and Db stored in 13, other red data D is calculated based on the recorded color data Dg.
Registration correction processing is written as 1- in r and blue data Db) L-- Registration correction data Dcr for each color to be performed in each complement 1 circuit SR, 6B of the color compensation + E processing unit 6; A central processing unit (cpU) 14 that calculates Dcb by interpolation processing, and each color registration sleeve 1 data D c calculated by this CPU 14
It is provided with correction data memories 15 and 16 that respectively store r, D and cb.

Then, during the actual photographing operation, the control unit 1O controls 1-
Each supplementary 1 data memory 15.16 to each color register) L
/- Read out the shading correction data Dcr, DCb and supply them to the registration correction processing section 6 mentioned above through the decoders 17 and 18, respectively, to control the operation of the registration correction processing section 6. It has become.

The operations of the F: reporter correction data memories 15 and 16 and the decoders 17 and 18 are controlled by a memory controller 19.

Here, the cash register storage in this example.

Regarding the basic principles of color correction processing, we will explain the registration error of two optical images by red light R and green light G, and the concept of its correction.

FIGS. 4A and 4B show overlay errors of images of each color, that is, registration, caused by the aberration of the imaging optical system. ! The 1:1 difference and its correction process are shown in a one-dimensional model.

In this -dimensional model, as shown in FIG. It is assumed that there is a registration error of Δ between the image point Pr (hereinafter academically referred to as the R image point) formed by the red light RdL (referred to as the G image point).

In addition, a solid-state image sensor such as a CCD that creates a tactile pixel structure performs spatial mapping of the subject's bones at each pixel pitch P as shown in 41<H, and It is assumed that the true G image point Pg corresponds to the sample point P2 on the imaging surface SC of the solid-state image sensor.

And 1. If sample I1 of the red light R component' at sample point P is R(P■), ``-7 imaging plane 5C)-,
Test 4IiliR'''(Pa-Δ) in the R image fj, p 1, i.e. (P■-Δ) is.

R"(P■-Δ)ζα, R(P■-+)+(1-〇)・
R(Pa) (where α=Δ/P) can be obtained by linear interpolation. Therefore,
Registration Mi Positive 91> FF if,
h G ftl, 1. < p If g is the standard, then 1-
The estimated value R'''(P--Δ) at the R image point Pr is expressed as 'M
This can be done by replacing it as /j.

That is, the signal R'(
P■) can be given by the formula R'(P■)±1(''(P■-Δ) = α・R(P■-+)+(1-α)・R(P■) can.

Furthermore, the concept of registration correction using the one-dimensional model described above can be extended to a -dimensional model, for example, as shown in FIG. 5, and in this two-dimensional model,
Registration sleeve correct 3! Signal R' after LFll (■
, n), R'(m, n) = a, β・R(m, a) ◆ (
1-a)-β・R(m,n)+a-(1-β)-R(m
, n)◆(1-a)(+-β)·R(*,n) (where α is Δx/Pi, β=Δy/Pte).

Here, if the registration error due to the debt ratio aberration of the imaging optical system is zero at the center of one screen, the error amount Δ tends to increase as the distance from the center of one screen increases, and Δ(r, θ)=Δ(r)·exp(jθ).

Therefore, the calculation for performing 11-line interpolation is α = Δ
wealth/P wealth = Δ(y), cos θ/Pgβ
= Δe/P1 = Δ(r)-sin θ
/Pt, R'(m++, nu) = h, R(m, n)+
i-R(s, n+(-1)')+J-R(at
(-1)'', n) + k-R(m+(-1)
', n+(-1)') However, h -(1-1α
1)-(1-+β1)i = (+-lα1) j=+α1. It is given by the formula: (1-1β1) k=+01·1β1. In this calculation formula, coefficient a,
b means that the sample point P (■, n) used for interpolation calculation is selected as shown in FIG. 6 according to the signs of α and β.

Note that the L control unit 10 has -1; the coefficients a, b, and
The CPU 14 outputs i, j, and k for each sample point using the CPU 14 for each color, and stores them in the storage (as correction data Dcr and Dab) and the reporter correction data memory 15 and 16, respectively. During the actual photographing operation, the coefficients a, b, and i.

j, 1-Registry storage seal correction data Dcr for each color from the reporter correction data memory 15.16;

If the Dcb is read out and supplied to the registration correction processing section 6 through each decoder 17, 18, and the registration correction processing section 6 is activated, the registration storage becomes extremely easy to use.

However, a large-scale arithmetic processing circuit is required to perform linear interpolation as described in 1-2 in the 1-2 two-dimensional model. Therefore, in this embodiment, substitution, ie, zero-order interpolation is adopted instead of 'F# line interpolation, and l-
The coefficients a, b, α, and β are supplied to the registration correction processing section 6. In this embodiment, the control section 10 indicates that the coefficient α is indicated by 1-bit data C, and that β is indicated by 2B/) data d.

In this embodiment, in the registration correction processing section 6 mentioned above, 1-Registration'M&! Circuit DL Tsuδ
, DL Teb, DL Tomi, DL Tomisu, DLxc
, DLcd.

Each data delayed by DLxe and DLzf is selected by each selector switch SWa and SWb controlled according to control data a and b supplied from the control unit IO, and this data is selected by the output of the first decoder DCa. "-" is selected by a selector switch SWc controlled in accordance with 1-bit data C indicating α, thereby obtaining data subjected to replacement processing in the horizontal direction of the image. Furthermore, in this embodiment, the decoder DCb with l-quantity 2 produces
Obtain decoded outputs U and V of 2-bit data d indicating
According to the decoded outputs U and V, the adder ADD adds the outputs selected by operating the selector switches SWu and SW, thereby performing interpolation processing in the vertical direction of the image. It is designed to display the data that has been obtained.

In the embodiment having the above-mentioned configuration, each selector switch SWa of the correction processing unit 6 is adjusted according to the coefficients a, b, c, and d given by the control unit IO.
, SWb, SWc, SWu, and SWv are operated to perform data replacement processing.
Each CCD image sensor 3R, 3G of the imaging unit 3,
For the imaging output obtained with 3B, high-quality color imaging can be performed by reliably performing 1/storage adjustment using electrical signal processing during the actual imaging operation.

[Effect of the invention P1 In the solid-state color imaging device according to the present invention, data replacement processing is performed based on the correction data while reading the correction data formed in advance from the storage means during actual imaging operation. Registration correction processing is applied to each color signal.

Electrical signal processing of the imaging output obtained by the solid-state image sensor enables reliable registration and high-quality color imaging, which satisfactorily achieves the intended purpose. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of a solid-state color imaging device according to the present invention, and FIG. Similarly, FIG. 3 is a block diagram showing the configuration of the correction circuit of the registration correction processing section 1-. FIGS. 4A and 4B are schematic diagrams showing, in a one-dimensional model, the concept of overlay errors of images of each color caused by the ratio aberration of the imaging optical system and their correction processing. FIG. 5 is a schematic diagram when the concept of the registration error correction process described above is extended to a two-dimensional model. FIG. 5 is a schematic diagram showing the principle of operation of the registration scene error correction process in the above embodiment using the above two-dimensional model. ! -9・Imaging lens 3...Imaging unit 3R, 3G, 3B-Fist・CCD image sensor 6・Fist-
Registration correction processing section 6R, 6B... Correction circuit 6G... Delay circuit 7... Process processing section 7R, 7G, 7B... Process processing circuit 8... Φ color encoder 9, Φ, output terminal

Claims (1)

[Claims] For each color signal obtained by capturing an image using color-separated imaging light of each color with a solid-state image sensor, the difference between one color signal serving as a reference and the other color signals is detected, and the difference between the above-mentioned other color signals is detected. Store correction data formed by neighborhood processing to select a pixel of the image according to the reference color signal, which obtains the reference color signal closest to the color signal corresponding to one pixel of the image according to the color signal. It is characterized by comprising a storage means, and a signal processing means that performs a registration correction process by a replacement process of selectively delaying the other color signal based on the correction data read from the storage means. solid-state color imaging device.