JP2002010276A - Imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a good image having fewer pseudo signals, uniform quality and higher resolution by a simpler signal processing than before when photographing monochromatic pictures, while maintaining a high speed frame rate by addition reading. SOLUTION: An imaging apparatus which photographs both monochromatic and colored images using a color imaging device uses an imaging device of multiple Bayer's arrangement such that a block consists of the same color four pixel (2×2) and arrangement of the blocks are regarded as Bayer's arrangement as a unit. When executing pixel addition, the device executes the same color addition reading during color photographing, and difference color addition reading during monochrome photographing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image pickup apparatus using a color image pickup element, and more particularly, to an image pickup apparatus for performing both color and monochrome image pickup.

[0002]

2. Description of the Related Art Conventionally, a single-plate type color image pickup apparatus using a Bayer array as a color array has been widely used. The Bayer array handled here is a periodic array in which two 2 × 2 pixels are arranged as a unit array. Two of the four pixels in the unit array have the same color, and two pixels of the same color are arranged diagonally. is there. FIG. 6 shows an example of a typical RGB Bayer arrangement.

[0003] A component color signal (R, G, B or Y, R-
Y, BY) are generated in various signal processing systems.
An example is shown below.

In the following, the coordinates of the original pixel point and the point of interest (generated pixel point) are (i, j), and index functions eG, eR, and eB are introduced for each of R, G, and B for simplicity. I will. . As shown in the left end and the upper end of FIG. 6, since the lattice phase is shifted by a half pitch between the original pixel point and the generated pixel point, even in the case of the coordinates of the same numerical value, the spatial position is different by that much. The index function eG is a function for extracting only a G component from a certain signal processing area, and is “1” for a G pixel area and “0” for another color pixel area. Becomes For example, R00, G0 in FIG.
When the index function eG is applied to four pixels of 1, G10, and B11, "0", "1", "1", and "0" are obtained. The same applies to eR and eB.

[0005] The high-frequency luminance signal HY (i, j) is shifted by one pixel at a time so as to include a shared pixel.
Pixel unit ｛(R00, G01, G10, B11), (G01, R02, B11, G12), (R0
2, G03, G12, B13), (G03, R04, B13, G14), (R04, G05, G14, B1
5),... Are generated using only the G included therein.

HY (i, j) = Σ [2 × 2 (i, j)] eG × P (i ′, j ′) / 2 where the symbol Σ [2 × 2 (i, j)] is P (i ′, j ′) means the summation (with pixel coordinates as variables) of a 2 × 2 (original pixel) 4-pixel area adjacent to the point of interest (i, j)
Indicates the signal output value of the original pixel at the coordinates (i ', j'). Therefore, the high-frequency luminance signal HY (i, j) {= HY (0,0)} corresponding to (i, j) = (0,0) in FIG.
It is generated from the sum of the image signals of G01 and G10 in the four adjacent pixels R00, G01, G10, B11. Similarly, HY (0, 1) is generated from the sum of the G01 and G12 image signals, and HY (0, 2) is generated from the sum of the G12 and G03 image signals.

[0007] Each high-frequency luminance signal HY determined in this manner.
Regarding (i, j), the high-frequency luminance signals HY (i-1, j), HY (i, j-1), HY of the adjacent coordinates are respectively provided.
A difference signal from (i, j + 1), HY (i + 1, j) is obtained, and this is set as a luminance edge signal AP (aperture signal).

[0008] For the low-frequency primary color signals LR, LG, and LB, a region larger than the high-frequency luminance signal HY, for example, a point of interest (i,
j) the average value of 4 × 4 = 16 pixels around, that is, for G, the average value of the pixel signals of 8 pixels included in 16 pixels,
R and B are calculated using the average value of the pixel signals of the corresponding four pixels included in the 16 pixels. Using the same notation as above, LR (i, j) = Σ [4 × 4 (i, j)] eR × P (i ′, j ′) / 4... R LG (i, j) = Σ [ 4 × 4 (i, j)] eG × P (i ′, j ′) / 8… G LB (i, j) = Σ [4 × 4 (i, j)] eB × P (i ′, j ′ ) / 4... B The low-frequency luminance signal LY is obtained by performing a matrix operation of 0.3R + 0.59G + 0.11B on the low-frequency primary color signals LR, LG, and LB, so that LY (i, j) = 0.3LR (i, j) + 0.59LG (i, j) + 0.11LB (i, j).

A wideband luminance signal Y and a color difference signal R-
Y (BY) is Y (i, j) = LY (i, j) + k × AP (i, j) RY (i, j) = LR (i, j) -LY (i, j) BY (i, j) = LB (i, j) -LY (i, j). k is a predetermined count. When the expression is represented by R, G, and B signals, R (i, j) = LR (i, j) + k × AP (i, j): G (i, j) = LG (i, j) + k × AP (i, j): B (i, j) = LB (i, j) + k × AP (i, j)) This equation is completely equivalent to the equation. Here, k in the equation is a coefficient for adjusting the edge high frequency characteristics.

That is, a low-frequency color signal is obtained by the equation,
A low-frequency luminance signal is obtained by the equation. A luminance signal of a wide band can be obtained by adding the luminance edge signal (high-frequency luminance signal) obtained by the expression to the expression. , And a high-frequency signal (and thus an achromatic color) is superimposed on the RGB signal, so that false color at the edge portion is hardly generated. (For example, if a (broadband) luminance signal is calculated as it is from the information of only the Bayer unit 4 pixels without performing such band-by-band processing and a simple matrix operation is performed, a false color is remarkably generated at the edge portion, which is inconvenient. In addition, since the high-frequency luminance signal is obtained only from G according to the formula, the jagged luminance signal due to the color edge portion is suppressed.

In other words, if the equation is rewritten, HY (i, j) = G (i, j + 1) + G (i + 1, j) to G (i, j) when i + j is an even number + G (i + 1, j + 1) to i + j are odd numbers, and the information of the original pixel is spread to four adjacent generation points, but the contribution to one generation point is １ ／. Since the information is averaged with the information of the adjacent original pixel point of the same color G, the jaggedness is not noticeable due to the smoothing effect.

Supplementing this point, obtaining the high-frequency luminance signal only from G means discarding the information of RB, which causes a decrease in SN. When the addition is performed, the luminance signal is strongly jagged due to the color edge portion, which is not preferable. That is,
If instead of the formula HY (i, j) = Σ [2 × 2 (i, j)] × P (i ', j')… ', if this is written down, HY (i, j) = R (i, j) + G (i, j + 1) + G (i + 1, j) + B (i + 1, j + 1)-When both i and j are even numbers, G (i, j) + R (i, j + 1) + B (i + 1, j) + G (i + 1, j + 1) When i is an even number and j is an odd number, G (i, j) + B (i, j + 1) + R (i + 1, j) + G (i + 1, j + 1)-When i is odd and j is even B (i, j) + G (i, j + 1) + G (i + 1, j) + R (i + 1, j + 1)-i and j are both odd numbers, and the original pixel information of R or B is
Contribution 1 spreads. That is, R or B has exactly the same information with respect to each of the four adjacent generation points. Therefore, for example, a red edge portion not including G and B information, a blue edge portion not including R and G information, and a red and blue edge portion have substantially the same state as the pixel density reduced to に. Therefore, the above-mentioned indentation occurs. In particular, since this occurs locally, it was even more noticeable than a uniform reduction in resolution of the entire image.

[0013] Under such circumstances, the processing using only the above G is used even if the SN is reduced. With the above-described processing, it is possible to generate a high-resolution image having the same number of pixels (pixel density) as the number of pixels of the image sensor (pixel density for the subject).

On the other hand, with the recent increase in the number of pixels of the image sensor, it is not always appropriate to record the same number of pixels as the image sensor when recording an image. In this regard, a technique for improving the sensitivity and the frame rate by setting a recording mode in which pixel addition is performed in particular is known. In particular, even when a color image sensor is used, the reading method is devised to add pixels of the same color. The present applicant has also applied for a technique of performing additive color imaging by performing the following (Japanese Patent Application No. 2000-1739).
No. 47). That is, at least for color imaging, the above-described conventional signal processing is used as it is even when pixel addition is performed.

[0015]

However, the above-mentioned prior art is based on the premise that the overall image quality at the time of color imaging is optimized. Alternatively, in addition to the pseudo signal (jagged color edge portion), the resolution was considerably low. That is,
Considering the distribution on the original image sensor of the two Gs to be added in the equation at the time when the same color four-pixel addition is performed, this spreads to a 4 × 4 = 16 pixel area.
This is by no means inferior to an image sensor having 1/4 pixels (pixel density) because it corresponds to a 2 × 2 pixel area of the image sensor, but is still improved in a high pixel image sensor. It can be regarded as an image quality deterioration factor in the sense that there is room for the above.

Accordingly, when performing black-and-white shooting (the subject is a general color subject not limited to black and white, but the purpose of use as an image is a black-and-white photograph), the luminance signal Y (i, i,
If only j) is recorded (or output to the outside), the prima facie purpose can be achieved, but it is necessary to perform signal processing relating to color information which is originally useless, and there is a problem that only a signal including the image quality deterioration is obtained. there were.

As for color photography, as described in the prior application of the present applicant, it is necessary to employ a special reading method with some contrivance in order to realize the addition of pixels of the same color. Specifically, in the above-mentioned prior art, the usable image pickup device is limited to the interlace scanning type, and it is necessary to use a mechanical shutter together. Alternatively, a technique of rearranging the order of pixels when reading out pixel signals as described in Japanese Patent Application Laid-Open No. H10-322601 may be used, but a special drive system must be prepared even in this case. In addition, there is a problem that the exposure end timing is slightly different for each pixel (line).

The present invention has been made in consideration of the above circumstances, and has as its object to maintain a high frame rate by addition reading and at least at the time of monochrome photographing, to attain a simpler signal than in the past. It is an object of the present invention to provide an image pickup apparatus capable of obtaining a good image without deterioration in image quality through processing. It is still another object of the present invention to provide an image pickup apparatus that does not require special signal reading for color image pickup.

[0019]

(Structure) In order to solve the above-mentioned problem, the present invention employs the following structure.

That is, the present invention provides a color image pickup device for picking up an image of a subject, driving means for driving the image pickup device to read out an image pickup signal, and processing the image pickup signal to produce a color image signal or a monochrome image signal of a predetermined format. An image pickup apparatus comprising: an image signal generation unit that can be selectively generated; and a mode control unit that selectively designates an image generated by the image signal generation unit to a color mode of color or a monochrome mode of monochrome. The driving unit is configured to perform a first readout drive when the mode specified by the mode control unit is the color mode, and a second readout drive different from the first readout drive when the mode specified by the mode control unit is the monochrome mode. Is performed.

Here, preferred embodiments of the present invention include the following.

(1) The first readout drive is a same-color addition readout drive for reading out while adding the charges of the same color pixels in the image sensor, and the second readout drive is for adding the charges of different color pixels in the image sensor. Different color addition read driving for reading.

(2) The color image sensor is 2 × 2 pixels.
And a color array of the image sensor is a multiple Bayer array in which four pixels in the block have the same color and the block array is a Bayer array. In addition, in the addition readout drive in the second readout drive, in addition to the charge transfer from the vertical transfer path to the horizontal transfer path of the image sensor, charge transfer for two pixels (two transfer units) is performed in each horizontal blanking period. In the first readout drive, the drive means adds pixel signal charges of the same color for two pixels, and in the second readout drive, adds pixel signal charges of different colors for two pixels. Thus, the configuration is such that the addition phase in the first and second read driving is inverted.

(3) In the multiple Bayer array, the block array is RG
A double RGB Bayer array that is a B Bayer array.

According to another aspect of the present invention, there is provided a color image pickup device for picking up an image of a subject, driving means for driving the image pickup device to read out an image pickup signal, and an image pickup device having a pixel density smaller than that of the image pickup device. A pixel density matching unit that generates unit pixel information of a pixel density corresponding to the pixel density of the generated image, and a color image signal or a monochrome image signal of a predetermined format can be selectively generated based on an output of the pixel density matching unit An image signal generation unit, and a mode control unit that selectively designates an image generated by the image signal generation unit to a color mode that is a color or a monochrome mode that is a monochrome. When the mode specified by the mode control unit is the color mode, the density matching unit adds pixel signal information of the same color. The image signal generation unit generates unit pixel information for generating the color image signal, and when the mode specified by the mode control unit is a monochrome mode, adds pixel signal information of all colors to generate an image. The pixel generating unit generates unit pixel information for generating the monochrome image signal in the signal generating unit.

(Function) According to the present invention, read driving suitable for each of color imaging and monochrome imaging is performed, and a unit pixel is generated by adding the same color for color and adding a different color for monochrome. There is no need for pixel point generation or color processing.

In particular, when the multiple Bayer array is used, the SN is improved by including RB information in the signal for monochrome photographing while securing a high frame rate, and each original pixel corresponds to only one generated pixel. Therefore, no pseudo signal (jagged color edge portion) is generated. In other words, it is possible to perform addition of pixels optimal for improving the image quality of a monochrome image without considering color generation. Therefore, it is possible to maintain a high frame rate by adding and reading, perform simple signal processing compared to the related art, and A good monochrome image without image quality degradation can be obtained. Further, in color photography, since four pixels of the same color that are adjacent to each other are added, a special driving method (rearrangement of pixel charges) and the like are not required, and the trouble caused by this is not caused.

Therefore, optimal signal processing for generating a monochrome image having a pixel density of 1/4 from a signal obtained by a color image pickup device having 4 million pixels, 6 million pixels or more multi-pixels can be realized. It is possible to improve the quality of a recorded image with a small number of signal processing.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to the illustrated embodiments.

FIG. 1 is a block diagram showing a circuit configuration of a digital camera according to an embodiment of the present invention.

In the figure, reference numeral 101 denotes a lens system including various lenses; 102, a lens driving mechanism for driving the lens system 101; 103, an exposure control mechanism for controlling the aperture of the lens system 101; A filter system for cutting; 105, a CCD color image sensor; 106, a CCD driver for driving the image sensor 105;
7, a pre-processing circuit including a gain control amplifier, an A / D converter, etc., 108, a digital processing circuit for performing color signal generation processing, matrix conversion processing, and other various digital processing, 109, a card interface, 110, a CF And the like, and 111 denotes an LCD image display system.

In the figure, reference numeral 112 denotes a system controller (CPU) for overall control of each unit, 113 denotes an operation switch system composed of various switches, and 114 denotes an operation display for displaying an operation state, a mode state, and the like. System, 115 is a lens driver for controlling the lens driving mechanism 102, 116 is a strobe as a light emitting means, 117 is an exposure control driver for controlling the exposure control mechanism 103 and the strobe 116, and 118 is various kinds of setting information and the like. 1 shows a non-volatile memory (EEPROM) for performing the operation.

In the digital camera of the present embodiment,
The system controller 112 performs all control in an integrated manner, and in particular, the exposure control mechanism 103 and the CCD driver 1
06, the exposure (charge accumulation) and signal readout are performed by controlling the driving of the CCD image pickup device 105, and the readout is performed by the digital process circuit 108 via the preprocess circuit 107.
After performing various signal processing, the data is recorded on the memory card 110 via the card interface 109. The CCD image sensor 105 is, for example, an interline progressive scan type having a vertical overflow drain structure.

FIG. 2 is a plan view showing the element structure of the CCD image pickup device 105. Photodiodes 201 are arranged in a matrix as light receiving elements.
A plurality of vertical CCDs 202 are arranged in the column direction between them,
One horizontal CCD in the row direction at the end of the vertical CCD 202
203 are arranged. And the photodiode 2
The signal charge stored in the first CCD 01 is read out to the vertical CCD 202 by the charge transfer pulse TG, and is transferred inside the vertical CCD 202 downward in the drawing. The signal charges transferred from the vertical CCD 202 are transferred to the horizontal CCD 203,
D203 is transferred leftward on the paper, and finally output via the readout amplifier 204.

FIG. 3 is a plan view showing a filter arrangement in the image sensor used in the present embodiment. A square pixel of 2 × 2 pixels of the pixel 301 is defined as a unit block 302, and four pixels in the unit block 302 have the same color. Each block 302 has a so-called Bayer arrangement in which Gs are arranged in a checkered pattern, and R and G are arranged in the remaining portions. Such an arrangement is hereinafter referred to as a multiple Bayer arrangement.

The image pickup device 105 used in the present embodiment
Is a progressive scanning type as described above, and has a pixel density twice as high as that of a conventional element to be compared on the assumption that four pixels (two horizontal pixels and two vertical pixels) are added. And As the imaging mode, a color imaging mode and a monochrome imaging mode can be manually selected. In addition, there is no non-addition mode, and always two-line addition drive (outputs V clocks in two transfer units during the H blanking period)
An image of 1/4 pixel number of the image sensor is recorded. Therefore,
The frame rate is improved to twice that of the standard (non-addition) driving. The horizontal addition is performed outside the element as described later.

Next, the operation of this embodiment will be described separately for a color photographing mode and a monochrome photographing mode.

(Color Mode) A unit pixel having a pixel density of 1/4 (the position is indicated by a black circle) is generated by a four-pixel addition process as shown in FIG. The generated unit pixel is
An RGB Bayer arrangement is used.

As a specific method of realizing the addition, the vertical addition performs a two-line addition drive. The drive pattern is as shown in FIG. 5A, and a V transfer clock for two pixels (two rows) is output in each horizontal blanking period. The clock phase output at that time is such that transfer pulses corresponding to the even-numbered pixel (row) and the next odd-numbered pixel (row) are output continuously (within the same H blanking). In the horizontal transfer path, electric charges of the upper and lower same-color two pixels are added.

For horizontal addition, adjacent pixels are added by digital operation after reading out a signal from the image sensor.
In this case, the addition is performed so that the pixel data of the even-numbered column and the pixel data of the next odd-numbered column are added.
Therefore, also in this case, the same color is added, and the four pixels of the same color as shown in FIG.

A conventional Bayer process (〜) is performed on the signal after addition, that is, Bayer unit pixel data of 画素 pixel number, and the obtained component color image signal is subjected to a recording process including compression, if necessary. And record it on the medium.

As described above, in this embodiment, a color image completely equivalent to a conventional Bayer color image pickup device (with a small number of pixels) can be obtained. The frame rate is not reduced by the addition driving, and the addition is simple and there is no change in pixel order.

(Monochrome Mode) A unit pixel having a pixel density of 1/4 (the position is indicated by a black circle) is generated by a 4-pixel addition process as shown in FIG. 4B. Here, FIG.
The difference is that the boundary of the block (solid line in the figure) is shifted by one pixel in the horizontal and vertical directions. In the generated unit pixels, all the pixels have the same information of R + 2G + B, and thus have an arrangement equivalent to a monochrome image sensor having uniform spectral characteristics.

As a specific method of realizing the addition, the vertical addition performs a two-line addition drive. The drive pattern is as shown in FIG. 5B, and a V transfer clock for two pixels (two rows) is output in each horizontal blanking period. The clock phase output at that time is such that transfer pulses corresponding to the odd-numbered pixel (row) and the next even-numbered pixel (row) are output continuously (within the same H blanking). In the horizontal transfer path, electric charges of upper and lower two pixels of different colors are added.

That is, the phase of the clock output or the addition is inverted with respect to the color.

For horizontal addition, adjacent pixels are added by digital operation after a signal is read from the image sensor.
The addition in this case is performed so as to add the pixel data of the odd-numbered column and the pixel data of the next even-numbered column.
Also in this case, the phase of the addition is inverted with respect to the color time, so that different colors (R + G and G + B have a common portion of G but are not the same) are added, and together with the vertical addition at the time of the previous reading, As described above, four pixels of all colors (R + 2G + B) are added as shown in FIG.

The obtained luminance image signal is used as a monochrome image signal (however, it is a matter of course that general signal processing such as gamma, Knee, and setup is appropriately performed as necessary). A recording process including compression is performed and recorded on a medium.

As described above, in the present embodiment, a monochrome image substantially equivalent to the monochrome image sensor having the same pixel density as the pixel density of the generated image (completely equivalent in terms of resolution) can be obtained. Therefore, the following effects can be obtained as compared with the monochrome (that is, the luminance signal in the color mode) in the conventional imaging apparatus.

(1) The resolution becomes extremely high.

(2) The signal processing is simple and there is no waste.

(3) Image uniformity is high. (Because each of the R and B pixels corresponds to only one generated pixel, no jaggedness occurs at the color edge.) (4) The frame rate is not reduced by the addition driving, the addition is simple, and the pixel order is changed. There is no particular problem because there is no such thing. In addition, in any of the color and monochrome image signal processing before recording processing, any conventionally known arbitrary signal processing such as gradation processing (γ, knee, setup) or color balance processing can be applied. It is.

The present invention is not limited to the above embodiment. The color arrangement of the image pickup device is not limited to the multi-bayer and may be any arrangement. For example, if a driving method is devised such as using a pixel order permutation driving technique, or if processing is performed only by digital operation after normal reading instead of addition reading, by using an image pickup device with a high pixel density in a conventional Bayer array, It is possible to realize the same color addition for color and all color addition for monochrome. Also in this case, if the monochrome unit pixel is generated by simply adding the four adjacent pixels, at least the effect of improving the image quality in monochrome and the effect of simplifying the processing can be obtained. In such a general case, an arbitrary number of additions can be used as long as the color arrangement and the pixel density of the image to be generated allow, as well as the four-pixel addition.

In the embodiment, the progressive C
Although the CD imaging device is used, not only the CCD but also various solid-state imaging devices can be used. Further, the present invention is not necessarily limited to a digital camera, but can be applied to a movie camera. In addition, various modifications can be made without departing from the scope of the present invention.

[0054]

As described above in detail, according to the present invention, different read-out driving (for example, same-color addition reading in color shooting, different-color addition reading in monochrome shooting) is performed in color shooting and monochrome shooting. Thus, at least at the time of monochrome photographing, it is possible to obtain an image pickup apparatus which eliminates waste of signal processing and has improved image quality as compared with the related art. Further, it is possible to obtain an image pickup apparatus that does not require special signal readout for color photographing. Further, these can be realized while maintaining a high frame rate by addition reading.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a circuit configuration of a digital camera according to an embodiment of the present invention.

FIG. 2 is a plan view showing the element structure of a CCD image sensor.

FIG. 3 is a plan view showing a filter array in the CCD image sensor.

FIG. 4 is a schematic diagram showing a color arrangement of a CCD image sensor and generation of unit pixels by addition.

FIG. 5 is a timing chart showing a pulse phase of addition driving.

FIG. 6 is a schematic diagram showing a Bayer array and a high-frequency luminance signal HY generation point in a conventional image sensor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 101 ... Lens system 102 ... Lens drive mechanism 103 ... Exposure control mechanism 104 ... Filter system 105 ... CCD color image sensor 106 ... CCD driver 107 ... Pre-process part 108 ... Digital process part 109 ... Card interface 110 ... Memory card 111 ... LCD image Display system 112 ... System controller (CPU) 113 ... Operation switch system 114 ... Operation display system 115 ... Lens driver 116 ... Strobe 117 ... Exposure control driver 118 ... Non-volatile memory (EEPROM) 201 ... Photodiode 202 ... Vertical CCD 203 ... Horizontal CCD 204: readout amplifier 301: pixel 302: unit block

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H04N 5/335 H01L 27/14 DF term (Reference) 2H054 AA01 4M118 AA10 AB01 BA10 BA13 CA03 DA01 FA06 FA13 GC01 GC08 5C024 AX01 CX03 CX11 DX01 GY04 GZ24 GZ29 JX36 5C065 AA01 BB22 BB48 CC01 DD01 DD02 DD07 GG49

Claims (5)

[Claims] 1. A color image pickup device for picking up an image of a subject, driving means for driving the image pickup device to read out an image signal, and selectively processing a color image signal or a monochrome image signal of a predetermined format by processing the image signal. An image pickup apparatus comprising: an image signal generating unit capable of generating; and a mode control unit that selectively designates one of a color mode in which an image generated by the image signal generating unit is in color and a monochrome mode in which the image is monochrome. The driving unit performs a first read driving when the mode specified by the mode control unit is a color mode.
An imaging apparatus configured to perform a second readout drive different from the first readout drive in the monochrome mode. 2. The first read-out drive is a same-color addition read-out drive in which the charges of the same-color pixels in the image sensor are read out while being added. The second read-out drive adds the charges of different-color pixels in the image sensor. 2. The imaging apparatus according to claim 1, wherein the apparatus is of a different color addition reading drive for reading while reading. 3. The image pickup device according to claim 1, wherein the color image pickup device has a length of 2 × 2 pixels.
A block array having four square pixels as a unit block, and the color array of the image sensor is a multiple Bayer array in which four pixels in the block are the same color and the block array is a Bayer array. In the addition readout drive in the first and second readout drives, when transferring charges from the vertical transfer path to the horizontal transfer path of the image sensor, charge transfer for two pixels (two transfer units) is performed in each horizontal blanking period. In the first read-out drive, the driving means adds two pixel signal charges of the same color for two pixels, and in the second read-out drive, two pixel signal charges of different colors are added. 3. The imaging apparatus according to claim 2, wherein an addition phase in the first and second read driving is inverted so that the minute addition is performed. 4. The imaging apparatus according to claim 3, wherein said multiple Bayer array is a multiple RGB Bayer array in which said block array is an RGB Bayer array. 5. A color image pickup device for picking up an image of a subject, driving means for driving the image pickup device to read out an image pickup signal, and a method for generating a generated image when a pixel density of a generated image is smaller than a pixel density of the image pickup device. A pixel density matching means for generating unit pixel information of a pixel density corresponding to the pixel density of the image density, and an image signal capable of selectively generating a color image signal or a monochrome image signal of a predetermined format based on an output of the pixel density matching means An image pickup apparatus comprising: a generation unit; and a mode control unit that selectively designates an image generated by the image signal generation unit to be a color mode that is a color mode or a monochrome mode that is a monochrome mode. When the mode specified by the mode control means is a color mode, the image signal generation is performed by adding pixel signal information of the same color. Generating unit pixel information for generating the color image signal in the generating unit, and when the mode specified by the mode control unit is a monochrome mode, adding the pixel signal information of all colors to the image signal generating unit. An imaging apparatus for generating unit pixel information for generating the monochrome image signal according to (1).