JP2001245308A - Image pickup device for quickly picking up still color picture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image pickup device for quickly picking up a still color picture, which can quickly obtain a color still picture with high resolution. SOLUTION: In the image pickup device for quickly picking up a still color picture of this invention, which shifts pixels by moving a solid-state image pickup device provided with color filter elements of Bayer arrangement, the photoelectric conversion elements arranged in matrix are arranged vertically and horizontally at an arrangement interval of 1/N (N is an odd number), the solid-state image pickup device is moved up to (N-1) times vertically and horizontally at an arrangement interval of M/N (M is an even number) with respect to the arrangement interval of the photoelectric conversion elements to shift the pixels with respect to horizontally/vertically moving positions in the matrix, detected image signals are composited, and color interpolation is applied to the composite image signal to obtain an image signal having a 3-color signal from each horizontally/vertically arranged position of the matrix.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color still image rapid imaging apparatus for quickly obtaining a high-resolution color still image.

[0002]

2. Description of the Related Art A conventional color still image pickup apparatus detects an image signal with a solid-state image pickup device and forms an image. The solid-state image pickup device includes a large number of pixels arranged in a two-dimensional matrix. And a color filter is fixed on the front surface thereof.

FIG. 10 is a partial front view of a conventionally used color filter 2. R indicates a red color filter element, G indicates a green color filter element, B
Denotes a blue color filter element, which is a color filter element of three primary colors of light.

A red color filter element R, a green color filter element G, and a blue color filter element B are arranged in a mosaic pattern, and this arrangement is called a Bayer arrangement. Are located. In this arrangement, a row in which red color filter elements R and green color filter elements G are alternately arranged horizontally and a row in which green color filter elements G and red color filter elements R are alternately arranged horizontally are vertically arranged. , And the green color filter elements G are arranged in a checkered pattern.

[0005] A large number of photoelectric conversion elements 3 arranged in a matrix on the solid-state imaging device 1 are installed at positions opposing red color filter elements R, green color filter elements G, and blue color filter elements B of the color filters 2, respectively. ing. Therefore, each photoelectric conversion element 3
Since any one of the red color filter element R, the green color filter element G, and the blue color filter element B is disposed on the front surface, the signal that can be extracted is any one of red, green, and blue color signals. Therefore, although it is called pixel shift, the solid-state imaging device 1 is indicated by an arrow S1.
As shown in the figure, it moves horizontally by the arrangement interval P, then moves downward by the arrangement interval P, further moves by the arrangement interval P in the horizontal direction, and a total of four positions including the position before the movement and each moved position , An image signal is detected, and three color signals are obtained for each arrangement position of the photoelectric conversion elements 3 to form a color still image.

Further, in order to form a color still image with a higher resolution by the solid-state imaging device 1, it is possible to perform pixel shifting so that the solid-state imaging device 1 is moved at a half interval.

FIG. 11 is a partial front view of a conventionally used color filter 2 when the solid-state imaging device 1 is moved at an arrangement interval of 1 / 2P. The solid-state imaging device 1 is fixed to the back surface of the color filter 2, and the solid-state imaging device 1 includes a large number of photoelectric conversion elements 3 arranged in a matrix, and a red color filter element R and a green color filter element G of the color filter 2, respectively. , And blue color filter element B.

[0008] As shown by arrow S2, the solid-state imaging device 1 is moved three times in the horizontal direction at a 1/2 arrangement interval of 1 / 2P.
Then, it is moved downward by 1/2 array interval 1 / 2P and
It moves three times in the horizontal direction at an array interval of 1 / 2P, and then moves downward by half an array interval of 1 / 2P, and moves three times horizontally at an array interval of 1 / 2P. , And further down 1 /
Move by 2P array interval 1 / 2P and move to 1/2 array interval 1 /
It moves three times in the horizontal direction in 2P, detects image signals at a total of 16 positions including the position before the movement and each moved position,
A color still image can be formed by obtaining three color signals at an arrangement interval of 1 / 2P of 1/2. further,
In order to form a still higher-resolution color still image with the solid-state imaging device 1, a pixel shift that moves the solid-state imaging device 1 at an array interval of で き る may be performed.

FIG. 12 is a partial front view of a conventionally used color filter 2 when the solid-state imaging device 1 is moved at an arrangement interval of 1 / 3P of 1/3. The solid-state imaging device 1 is fixed to the back surface of the color filter 2, and the solid-state imaging device 1 includes a large number of photoelectric conversion elements 3 arranged in a matrix, and a red color filter element R and a green color filter element G of the color filter 2, respectively. , And blue color filter element B.

The solid-state imaging device 1 is moved five times in the horizontal direction at a 1/3 array interval of 1/3 as shown by an arrow S3.
Then, it moves downward by 1/3 array interval of 1 / 3P and
3 times in the horizontal direction at an interval of 1 / 3P, and
The horizontal movement 5 times at an arrangement interval of 1 / 3P is further repeated 4 times, and a total of 36 image signals of the position before the movement and each moved position are detected. It is also possible to obtain color signals of three colors at an arrangement interval of 1 / 3P to form a color still image.

[0011]

However, the conventional color still image pickup apparatus has the following problems.

As described above, the conventional color still image pickup apparatus can form a color still image with increased resolution by performing pixel shift, and in particular, it can reduce the resolution to 1/3.
Although a high-resolution color still image can be formed by pixel shifting at an array interval of, the time-consuming pixel shifting must be performed 35 times to detect image signals at a total of 36 locations. However, there is a problem that it takes a lot of time to form a color still image.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and an object of the present invention is to provide a color still image rapid imaging apparatus capable of rapidly obtaining a high-resolution color still image.

[0014]

According to the present invention, there is provided a color still image rapid imaging apparatus according to the present invention, wherein photoelectric conversion elements are arranged in a matrix at predetermined arrangement intervals, and red and blue are arranged in a Bayer array on the front surface of each of the photoelectric conversion elements. A solid-state imaging device in which three green color filter elements are provided so as to correspond to each other; and a movement driving unit that moves the solid-state imaging device and shifts pixels, and is provided in advance with respect to the arrangement interval of the photoelectric conversion elements. A matrix-like vertical / horizontal arrangement position is determined at a 1 / N arrangement interval based on the determined odd number N, and a vertical / horizontal arrangement at an M / N arrangement interval based on a predetermined even number M and the N with respect to the arrangement interval of the photoelectric conversion elements. The solid-state imaging device is moved up to N-1 times to perform a pixel shift to a vertical and horizontal movement position in a matrix, and it is detected before the pixel is shifted and when the pixel is shifted. A plurality of image signals to obtain an image signal having a color signal of any one of red, blue, and green at each of the vertical and horizontal arrangement positions of the matrix, and performing color interpolation from the synthesized image signal to perform the matrix formation. Image signals having three color signals for each of the vertical and horizontal array positions.

Further, the odd number N is 3 and the even number M is 2, and the solid-state imaging device is moved up to twice at an arrangement interval of 2/3 with respect to the arrangement interval of the photoelectric conversion elements, so as to move vertically and horizontally in a matrix. Pixel shift is performed at the position.

In the color interpolation, color interpolation of the green signal is performed by averaging four green signals at upper, lower, left and right positions adjacent to the interpolation position, and two color signals at upper and lower positions adjacent to the interpolation position are averaged. The red signal is averaged by averaging two red signals at the left and right positions adjacent to the interpolation position, or by averaging four red signals at oblique upper, lower, left and right positions of the interpolation position. The color interpolation of the blue signal is performed in the same manner as the color interpolation of the red signal.

In the color interpolation, color interpolation of the green signal is performed by averaging four green signals at upper, lower, left and right positions adjacent to the interpolation position, and the green signal at the interpolation position is adjacent to the interpolation position. The ratio between the green signal at the position and the red signal at the position adjacent to the interpolation position is multiplied by the color interpolation of the red signal at the interpolation position, and the color interpolation of the blue signal is performed in the same manner as the color interpolation of the red signal. And

In the color interpolation, the difference D1 between the two green signals above and below the interpolation position and the difference D1 between the two green signals above and below the interpolation position are calculated.
The difference D2 between the green signals is calculated, and when there is a difference between the difference D1 and the difference D2 that is equal to or greater than a preset value, the two green signals having the smaller difference are averaged to perform color interpolation of the green signals. When there is no difference between the difference D1 and the difference D2 that is equal to or greater than a preset value,
The difference D3 between the red signal at the interpolation position and the red signal R vertically adjacent thereto and the difference D4 between the red signal at the interpolation position and the red signal horizontally adjacent thereto are calculated, and the difference D3 is calculated as the difference D4
When the difference is smaller, the green signals above and below the interpolation position corresponding to the vertical difference D3 are averaged to perform color interpolation of the green signal. When the difference D4 is equal to or smaller than the difference D3, the interpolation corresponding to the horizontal difference D4 is performed. The green signals on the left and right of the position are averaged, and color interpolation of the green signals is performed.

Further, the pixel shift is performed by reciprocating horizontally or vertically.

Embodiments of the present invention will be described below.

FIG. 1 is a block diagram for explaining the overall structure of a color still image rapid imaging apparatus 10 according to the present invention. A color still image rapid imaging device 10 includes a solid-state imaging device 11 that detects a color image signal, and a movement driving unit 2 that moves the solid-state imaging device 11 vertically and horizontally at predetermined intervals.
2, a memory unit 25 for storing a color image signal, and an image synthesizing unit 2 for synthesizing the image signals stored in the memory unit 25
6, a color interpolation unit 27 that performs color interpolation of the image signal synthesized by the image synthesis unit 26, a control unit 20 that controls the solid-state imaging device 11, the memory unit 25, the image synthesis unit 26, and the color interpolation unit 27. It has.

The solid-state imaging device 11 has a large number of photoelectric conversion elements 13 (see FIG. 2) arranged in a matrix and has a color filter 12 (see FIG. 2) fixed on the front surface. The color filter 12 includes a Bayer-arranged red color filter element R, a green color filter element G,
Each of the blue color filter elements B is a photoelectric conversion element 13
Are provided so as to correspond to each. In addition, the solid-state imaging device 11 is read by a reading pulse signal generated by the pulse generation unit 21 in response to a reading instruction from the control unit 20 and outputs an image signal.
In response to a pixel shift movement instruction from 0, the pulse generator 21
The movement is performed at a predetermined interval by the movement drive unit 22 by the movement pulse signal generated in step (1).

The memory section 25 is amplified by the amplifier 23 and
The image signal that has been A / D-converted by the D-converter 24 is stored in the memory 1 for each of the moving positions before and after the pixel shift of the solid-state imaging device 11 according to an instruction from the controller 20.
M, 2M... 9M.

The image synthesizing unit 26 synthesizes the image signals stored in the memories 1M, 1M,... 9M according to an instruction from the control unit 20, and the color interpolation unit 27 synthesizes the image signals according to the instruction from the control unit 20. Color interpolation is performed based on the image signal.

With the above arrangement, an image signal having three color signals can be obtained at an arrangement interval of 1/3 smaller than the arrangement interval of the photoelectric conversion elements 13. The details will be described below.

FIG. 2 is a partial plan view of the color filter 12 fixed to the front surface of the solid-state imaging device 11. The color filter 12 is the same as the color filter 2 shown in FIG. 10, and the color filter elements of the red color filter element R, the green color filter element G, and the blue color filter element B are arranged in a Bayer arrangement vertically and horizontally at every arrangement interval P. They are arranged in a mosaic.

A large number of photoelectric conversion elements 13 arranged in a matrix on the solid-state image pickup device 11 fixed to the back surface of the color filter 12 include respective red color filter elements R, green color filter elements G, and blue color filter elements B. The color signal that is provided at a position opposing the color filter element and can be extracted from the photoelectric conversion element 13 is a data signal of any of red, green, and blue.

.. In the horizontal direction X and 1, 3, 3... In the vertical direction Y.
The matrix-like vertical / horizontal arrangement position at / 3P is a detection position of a color signal detected by the photoelectric conversion element 13 of the solid-state imaging device 11 when the pixel is shifted. An image signal is formed by a large number of color signals detected from the photoelectric conversion elements 13.

The solid-state imaging device 11 includes a moving drive unit 22
(See FIG. 1), the pixel is shifted to a matrix-like vertical and horizontal movement position at an arrangement interval of 2 / 3P and pixels are shifted. Although the solid-state imaging device 11 moves as a whole,
For example, the red color filter element R at the coordinate position A1 of (X1, Y1) has the coordinate position A2 of (X3, Y1) and (X
5, Y1) twice to the coordinate position A3, to the lower (X5, Y3) coordinate position A4, and then to (X
(3, Y3) to the coordinate position A5 and (X1, Y3) coordinate position A6 twice in the horizontal direction, and further below (X1, Y3).
After moving to the coordinate position A7 of 5), it moves twice to the coordinate position A8 of (X3, Y5) and the coordinate position A9 of (X5, Y5). Therefore, image signals are detected at a total of nine positions, that is, the first coordinate position before the movement and the coordinate position when the pixel is shifted, and stored in the memory unit 25 (see FIG. 1). The pixel shift movement in which the reciprocating movement in the horizontal direction (also in the vertical direction) in FIG. 2 is repeated can be performed with a minimum movement distance.

FIG. 3 shows a partial plan view of the color filter 12 fixed to the front surface of the solid-state imaging device 11 (see FIG. 2). FIG. 3A shows a partial plan view of the color filter 12 before moving. Fig. (A2), Fig. (A3) ... Fig. (A
9) is a partial plan view of the color filter 12 at a position where the pixel is shifted in the direction described with reference to FIG.

The color filter 1 before movement shown in FIG.
2 is the vertical and horizontal arrangement interval P from the coordinate position of (X1, Y1).
Each of the red color filter element R, the green color filter element G, and the blue color filter element B is disposed for each of the color filter elements R, the green color filter element G, and the blue color filter element B. Any one of red, green, and blue color signals is detected from the photoelectric conversion element, becomes an image signal from the solid-state imaging device 11, and is stored in the memory 1M of the memory unit 25 (see FIG. 1).

The color filter 12 in FIG.
The pixel shift is performed horizontally at an array interval of 2 / 3P of 2/3. The red color filter element R, the green color filter element G and the green color filter element G are arranged at every array interval P from the coordinate position of (X3, Y1) vertically and horizontally. Any one of the blue color filter elements B is disposed, and a color signal is detected and read from the photoelectric conversion elements fixed on the back surface of the red color filter element R, the green color filter element G, and the blue color filter element B. The conversion is performed to become an image signal from the solid-state imaging device 11 and stored in the memory 2M of the memory unit 25. A red color filter element R shown in a dotted circle,
Green color filter element G, blue color filter element B
Indicates a situation where a color signal has already been detected. The read conversion is performed, for example, from the coordinate position (X1, Y1) to (X3, Y1).
The color signal of the red color filter element R moved to the coordinate position of 1) is converted into a red signal of the coordinate position of (X3, Y1).

Similarly, as described with reference to FIG. 2, FIG. 3 (A3), FIG. 3 (A4), FIG. 3 (A5), and FIG.
6), pixel shifts are performed at the matrix-like vertical and horizontal movement positions shown in FIGS. 3 (A7), 3 (A8), and 3 (A9), and color signals are detected at the respective movement positions to become image signals and become memory signals. Stored in the memories 3M to 9M of the unit 25, respectively.

FIGS. 3 (A3), 3 (A4) and 3 (A)
5), FIG. 3 (A7), and FIG. 3 (A8) show the color filter 1
2 is omitted, the color filter 12 in FIG. 3 (A6) is obtained when pixels are vertically shifted at an arrangement interval of 2 / 3P of 2/3, and is shown in FIG. 3 (A9). The color filter 12 in the final movement is obtained when the pixel is shifted twice vertically and horizontally twice at an arrangement interval of 2 / 3P of 2/3.
Any one of the red color filter element R, the green color filter element G, and the blue color filter element B is arranged at every arrangement interval P vertically and horizontally from the coordinate position of (2, Y2), and is fixed to the back surface of the color filter element. A color signal is detected from each of the detected photoelectric conversion elements, but since the color signal has already been detected at the coordinate position of the color filter element shown in the dotted circle, the arrangement interval of 1 / 3P
A color signal of any one of red, green, and blue arranged in a Bayer array is detected.

Therefore, as described above, the image synthesizing section 26
(See FIG. 1) combines the image signals stored in the memories 1M, 2M,... 9M, and outputs one of the red, blue, and green colors at every 1 / 3P array position of 1/3 matrixwise and horizontally. An image signal of one color per position having a color signal can be obtained.

FIG. 4 shows the arrangement interval of 1 / 3P in the vertical and horizontal directions.
FIG. 3 shows a situation in which color interpolation is performed from an image signal having one color signal at one position for each position, and an image signal having three color signals at one position is obtained for every 1 / 3P of the arrangement interval vertically and horizontally. . This color interpolation can be performed by the color interpolation unit 27 shown in FIG.

As shown in FIG. 4A, an image signal having one color signal at one position in each of the vertical and horizontal arrangement intervals of 1 / 3P has 1, 2, 3... , And the coordinates of the positions 1, 2, 3,... In the vertical direction Y can be shown in a matrix pattern (image signal pattern).

FIG. 4B shows a 1 / 3P arrangement interval of 1/3.
.. In the horizontal direction X and 1, 2, 3 in the vertical direction Y.
3 is a pattern (green signal pattern) of the green signal G at the coordinates of the position 3... Since the green signals G are arranged in a checkered pattern, they are adjacent when performing color interpolation of the green signal G. For example, at the coordinate position (X5, Y3), color interpolation of the green signal G can be performed as indicated by an arrow.

FIG. 4C shows a 1 / 3P arrangement interval of 1/3.
.. In the horizontal direction X and 1, 2, 3 in the vertical direction Y.
3 is a pattern (red signal pattern) of the red signal R at the coordinates of the position 3... Since the red signals R are arranged in a matrix, they are adjacent when performing color interpolation of the red signal R. Left, up, down, or obliquely up, down, left, and right red signals R, for example,
The coordinates of (X2, Y1), (X1, Y2), and (X2, Y2) can be subjected to color interpolation of the red signal R as indicated by arrows.

FIG. 4D shows a 1 / 3P arrangement interval of 1/3.
.. In the horizontal direction X and 1, 2, 3 in the vertical direction Y.
The blue signal B is patterned (blue signal pattern) at the coordinates of the position 3... Since the blue signals B are arranged in a matrix, the same operation as the color interpolation of the red signal R is performed. For example, (X3, Y2),
At the coordinate positions (X2, Y3) and (X3, Y3), color interpolation of the blue signal B can be performed as indicated by arrows.

FIG. 5 shows a first embodiment for performing color interpolation of the red signal R and the green signal G.

FIG. 5A shows a situation in which the green signal G is color-interpolated into the green signal pattern obtained by the pixel shift, and the signal values of a total of four adjacent green signals G are averaged. Can be done.

FIGS. 5 (B1), 5 (B2) and 5 (B)
3) shows a situation in which the red signal R is color-interpolated into a red signal pattern having a 2/3 array spacing of 2/3 in a matrix obtained by the pixel shifting, and in FIG. The signal values of the two red signals R can be averaged, and in FIG. 5B2, the signal values of the upper and lower two red signals R can be averaged, and the signal values of FIG.
In this case, it is possible to average the signal values of a total of four red signals R obliquely up, down, left, and right. Since the blue signal B is arranged in a matrix like the red signal R, the blue signal B
Can be performed in the same manner as for the red signal R.

Also, as a second embodiment, the color interpolation of the green signal G is performed by averaging four green signals G at upper, lower, left and right positions adjacent to the interpolation position of the green signal G to be interpolated. The color interpolation of the signal R is performed by the ratio of the green signal G at the interpolation position of the red signal R to be interpolated to the green signal G at the position adjacent to the interpolation position. Can be performed. Also in this case, since the blue signal B is arranged in a matrix like the red signal R, the color interpolation of the blue signal B is performed by the red signal R
Can be performed in the same manner as described above.

FIGS. 6, 7, and 8 show a third embodiment for performing color interpolation of the green signal G, the red signal R, and the blue signal B.

FIG. 6 shows a flow when the green signal G is color-interpolated into the green signal pattern obtained by the pixel shift. In the color interpolation of the green signal G at the interpolation position Ha, first, the difference (absolute value) D2 between the two green signals G, G above and below the interpolation position Ha, and the two green signals left and right at the interpolation position Ha G, the difference (absolute value) D2 of G, and the difference D
1 is compared with the difference D2. If the difference between the difference D1 and the difference D2 is greater than or equal to a predetermined value, the difference D
A G average value for averaging the two green signals G having the smaller difference between 1 and the difference D2 is calculated, and the G average value is color-interpolated to the interpolation position Ha.

When the comparison result of the difference D1 and the difference D2 is small and smaller than a preset value, the difference between the red signal R at the interpolation position Ha and the red signal R adjacent to the interpolation position Ha in the vertical direction is obtained. (Absolute value) D3 and the difference (absolute value) D4 between the red signal R at the interpolation position Ha and the red signal R adjacent to the interpolation position Ha in the horizontal direction are calculated, and the difference D3 and the difference D4 are compared. When the difference D3 is smaller than the difference D4, the G average value of the green signals G, G above and below the interpolation position Ha corresponding to the vertical difference D3 is calculated, and the G average value is color-interpolated to the interpolation position Ha. . When the difference D4 is equal to or smaller than the difference D3, the interpolation position H corresponding to the difference D4 in the left-right direction is used.
The G average value of the left and right green signals G, G is calculated, and the G average value is color-interpolated to the interpolation position Ha.

FIG. 7 shows a flow for color interpolation of the red signal R. A flow for color interpolation at the center interpolation position Hc of a red signal pattern having an arrangement interval of 2 / 3P in a matrix obtained by the pixel shift. Is shown.

For example, the center interpolation position H of (X2, Y2)
c, the color interpolation of the red signal R is performed first at the center interpolation position Hc.
Of the green signal G of (X3, Y1) of the green signal pattern shown in FIG.
) To calculate a value obtained by multiplying the red signal R at a position (X3, Y1) obliquely above the center interpolation position Hc of the red signal pattern shown in FIG. 7
Color interpolation is performed at the interpolation position Hc of (X2, Y2) shown in (C). The same operation can be performed for the other center interpolation positions Hc as shown in FIG. 7C.
The color interpolation of the red signal R can be performed.

FIG. 8 shows a flow for color interpolation of the red signal R. The vertical interpolation position Hv and the left and right interpolation position Hh of the red signal pattern having the arrangement interval of 2 / 3P in a matrix obtained by the pixel shift are shown. The flow at the time of performing color interpolation of the signal R is shown.

For example, the left and right interpolation position H of (X2, Y1)
h, the color interpolation of the red signal R is first performed by using the green signal G of (X2, Y1) in the green signal pattern shown in FIG.
The ratio Ph (/) of the green signal G of (X3, Y1) is calculated, and the red signal R at the horizontal position (X3, Y1) of the left-right interpolation position Hh of the red signal pattern shown in FIG.
Is multiplied by the ratio Ph, and the value is color-interpolated to the left and right interpolation position Hh of (X2, Y1) shown in FIG. The same can be applied to the other left and right interpolation positions Hh.

Similarly, color interpolation can be performed for the upper and lower interpolation positions Hv, and the color interpolation of the red signal R is performed for all the upper and lower interpolation positions Hv and the left and right interpolation positions Hh as shown in FIG. Can be. Therefore, the color interpolation of the red signal R can be performed at all the interpolation positions of the red signal R by the flows shown in FIGS. Since the blue signal B is arranged in a matrix like the red signal R, the color interpolation can be performed in the same manner as the red signal R.

FIG. 9 shows a flow of a fourth embodiment in which color interpolation of the green signal G is performed in the same manner as in the third embodiment, and color interpolation of the red signal R and the blue signal B is performed.

When color interpolation is performed at the center interpolation position Hd of a red signal pattern having an arrangement interval of 2 / 3P in a matrix obtained by the pixel shift, for example, (X2, Y2)
When the color interpolation of the red signal R is performed at the center interpolation position Hd, first, (X) of the green signal pattern shown in FIG.
The ratio Pd (green signal G / G average value) of the G average value of the green signal G at (1, Y3) and the green signal G at (X3, Y1) and the green signal G at (X2, Y2) is The red signal R at the position (X1, Y3) obliquely below the center interpolation position Hd and the red signal at the position obliquely above the center interpolation position Hd (X3, Y1) of the red signal pattern shown in FIG. A value obtained by multiplying the R average value with R by the ratio Pd is calculated, and the value is color-interpolated to the (X2, Y2) interpolation position Hc shown in FIG. 7C. The same can be performed for the other center interpolation positions Hd, and the color interpolation of the red signal R can be performed for all the center interpolation positions Hd as shown in FIG. 9C.

When the color interpolation of the red signal R is performed at the upper and lower interpolation positions Hvd and the left and right interpolation positions Hhd of the red signal R pattern, similarly to the color interpolation of the center interpolation position Hd,
This can be performed based on the ratio between the G average value of the green signals G above and below or left and right of the interpolation position and the green signal G at the interpolation position. Since the blue signal B is arranged in a matrix like the red signal R, the color interpolation can be performed in the same manner as the red signal R.

As described above, the color still image rapid imaging apparatus 10 obtains an image signal having three color signals at every 1/3 arrangement interval in a matrix, which is finer than the arrangement interval of the photoelectric conversion elements. Can be. 1/3 of conventional
In pixel shifting, pixel shifting must be performed 35 times in order to obtain image signals of three colors vertically and horizontally at every ３ arrangement interval, and image signals must be detected at a total of 36 places before and after movement. Requires a lot of time to detect a still image, and a very long time to detect a still image. However, the color still image rapid imaging apparatus 10 performs eight pixel shifts and performs a total of nine image signal shifts before and after movement. , And color interpolation is performed, so that pixel shift and color interpolation can be performed in a short time, and a color still image can be detected quickly.

In the above embodiment, the pixel is shifted vertically and horizontally twice at an arrangement interval of 2/3 to obtain image signals of one position and three colors at each arrangement interval of 1/3 both vertically and horizontally.
It is also possible to shift the pixel three times or more and obtain an image signal by overlapping.

In the above embodiment, the detection positions of the matrix-like color signals are determined vertically and horizontally at an arrangement interval of 1/3.
Pixels are shifted vertically and horizontally at matrix arrangement positions at an arrangement interval of / 3. However, matrix arrangement is performed at a 1 / N arrangement interval by a predetermined odd number N with respect to the arrangement interval of photoelectric conversion elements. The position is determined, and M is determined by the predetermined even number M and the N with respect to the arrangement interval of the photoelectric conversion elements.
It is also possible to move the solid-state imaging device vertically and horizontally N-1 times at an arrangement interval of / N to shift pixels to vertical and horizontal movement positions in a matrix. In this case, too,
In the same manner as in the color interpolation of the second, third, and fourth embodiments, it is possible to obtain an image signal having three color signals for each of the vertical and horizontal arrangement positions in a matrix.

Further, in the above embodiment, the solid-state imaging device is moved horizontally, and further, the solid-state imaging device is moved vertically, and each time the solid-state imaging device is moved horizontally, the pixels are shifted. However, the solid-state imaging device may be moved vertically, the solid-state imaging device may be moved horizontally, and each time the solid-state imaging device is moved, the pixel may be shifted.

[0059]

According to the color still image rapid imaging apparatus of the present invention, the photoelectric conversion elements are arranged in a matrix at a predetermined arrangement interval, and three colors of red, blue and green are arranged on the front surface of each of the photoelectric conversion elements. A solid-state imaging device provided with corresponding color filter elements,
A moving drive unit for moving the solid-state imaging device and shifting pixels, and determining a matrix-like vertical and horizontal arrangement position at a 1 / N arrangement interval by a predetermined odd number N with respect to the arrangement interval of the photoelectric conversion elements, The solid-state imaging device is moved vertically and horizontally by N-1 times at an arrangement interval of M / N determined by a predetermined even number M and the N with respect to the arrangement interval of the photoelectric conversion elements, and the pixels are shifted to vertical and horizontal movement positions in a matrix. And a plurality of image signals detected before pixel shifting and when pixel shifting is performed are combined, and an image signal having any one of red, blue and green color signals at each of the vertical and horizontal arrangement positions of the matrix is provided. , And color interpolation is performed based on the synthesized image signal to obtain an image signal having three color signals at each of the vertical and horizontal matrix positions. Image can be obtained quickly.

The odd number N is 3 and the even number M is 2, and the solid-state imaging device is moved up to twice at an arrangement interval of 2/3 with respect to the arrangement interval of the photoelectric conversion elements, and the matrix is moved vertically and horizontally. Since the pixel is shifted to the position, a desired high-resolution color still image can be quickly obtained with a small number of pixel shifts.

In the color interpolation, the color interpolation of the green signal is performed by averaging four green signals at upper, lower, left and right positions adjacent to the interpolation position, and two color signals at upper and lower positions adjacent to the interpolation position are obtained. The red signal is averaged by averaging two red signals at the left and right positions adjacent to the interpolation position, or by averaging four red signals at oblique upper, lower, left and right positions of the interpolation position. The color interpolation of the blue signal is performed in the same manner as the color interpolation of the red signal, so that the color interpolation can be easily and accurately performed.

In the color interpolation, color interpolation of the green signal is performed by averaging four green signals at the upper, lower, left and right positions adjacent to the interpolation position, and the green signal at the interpolation position is adjacent to the interpolation position. The ratio between the green signal at the position and the red signal at the position adjacent to the interpolation position is multiplied by the color interpolation of the red signal at the interpolation position, and the color interpolation of the blue signal is performed in the same manner as the color interpolation of the red signal. Therefore, color interpolation can be easily and accurately performed.

In the color interpolation, the difference D1 between the two green signals above and below the interpolation position and the difference D1 between the two green signals above and below the interpolation position are calculated.
The difference D2 between the green signals is calculated, and when there is a difference between the difference D1 and the difference D2 that is equal to or greater than a preset value, the two green signals having the smaller difference are averaged to perform color interpolation of the green signals. When there is no difference between the difference D1 and the difference D2 that is equal to or greater than a preset value,
The difference D3 between the red signal at the interpolation position and the red signal R vertically adjacent thereto and the difference D4 between the red signal at the interpolation position and the red signal horizontally adjacent thereto are calculated, and the difference D3 is calculated as the difference D4
When the difference is smaller, the green signals above and below the interpolation position corresponding to the vertical difference D3 are averaged to perform color interpolation of the green signal. When the difference D4 is equal to or smaller than the difference D3, the interpolation corresponding to the horizontal difference D4 is performed. Since color interpolation of the green signal is performed by averaging the green signals on the left and right of the position, color interpolation can be easily and accurately performed.

Further, the pixel shift is performed by reciprocating in the horizontal or vertical direction repeatedly.
Pixel shifting can be performed with a minimum moving distance.

[Brief description of the drawings]

FIG. 1 is a block diagram for explaining the entire structure of a color still image rapid imaging apparatus according to the present invention.

FIG. 2 is a partial plan view of a color filter fixed to a front surface of a solid-state imaging device.

FIG. 3 is a partial plan view of a color filter fixed to the front surface of the solid-state imaging device when a pixel is shifted.

FIG. 4 illustrates a situation in which color interpolation is performed from an image signal having one color signal at one position at every ３ arrangement interval in the vertical and horizontal directions to obtain an image signal having three color signals at one position.

FIG. 5 shows a first embodiment for performing color interpolation of a red signal and a green signal.

FIG. 6 shows a third embodiment in which color interpolation is performed, and shows a flow when color interpolation of a green signal is performed on a green signal pattern obtained by pixel shift.

FIG. 7 shows a third embodiment in which color interpolation is performed, and shows a flow when a red signal is color-interpolated at the center interpolation position of a red signal pattern having an arrangement interval of 2 / 3P in a matrix obtained by pixel shifting.

FIG. 8 shows a third embodiment for performing color interpolation, in which color interpolation of a red signal is performed at a vertical interpolation position and a horizontal interpolation position of a red signal pattern having an arrangement interval of 2 / 3P in a matrix obtained by pixel shift. Shows the flow.

FIG. 9 shows a flow of a fourth embodiment in which color interpolation of a green signal is performed in the same manner as in the third embodiment, and color interpolation of a red signal and a blue signal is performed.

FIG. 10 shows a partial front view of a conventionally used color filter.

FIG. 11 is a partial front view of a conventionally used color filter when the solid-state imaging device is moved at a half interval.

FIG. 12 is a partial front view of a conventionally used color filter when the solid-state imaging device is moved at an arrangement interval of 1/3.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 color still image rapid imaging device 11 solid-state imaging device 12 color filter 13 photoelectric conversion element 20 control unit 21 pulse generation unit 22 movement driving unit 25 memory unit 26 image synthesis unit 27 color interpolation unit

Claims (6)

[Claims] 1. A photoelectric conversion element is arranged in a matrix at a predetermined arrangement interval, and three color filter elements of red, blue, and green arranged in a Bayer array are provided on the front surface of each of the photoelectric conversion elements. A solid-state imaging device, and a movement drive unit for moving the solid-state imaging device to shift a pixel, wherein a matrix-shaped matrix is formed at a 1 / N array interval by a predetermined odd number N with respect to the array interval of the photoelectric conversion elements. The vertical and horizontal arrangement positions are determined, and M is determined by the predetermined even number M and the N with respect to the arrangement interval of the photoelectric conversion elements.
The solid-state imaging device is moved vertically and horizontally at an array interval of / N up to N-1 times to perform pixel shifting to a matrix-like vertical and horizontal moving position, and a plurality of images detected before pixel shifting and when pixel shifting is performed. The signals are combined to obtain an image signal having a color signal of any one of red, blue, and green for each of the vertical and horizontal matrix positions, and color interpolation is performed from the combined image signal to perform the vertical and horizontal matrix operations. A color still image rapid imaging apparatus characterized in that an image signal having three color signals is obtained for each arrangement position. 2. The odd number N is 3, and the even number M is 2,
2. The color according to claim 1, wherein the solid-state imaging device is moved up to twice at an arrangement interval of 2/3 with respect to an arrangement interval of the photoelectric conversion elements, and pixels are shifted to vertical and horizontal movement positions in a matrix. Still image rapid imaging device. 3. The color interpolation performs color interpolation of a green signal by averaging four green signals at upper, lower, left, and right positions adjacent to an interpolation position, and performs color interpolation of two green signals at upper and lower positions adjacent to the interpolation position.
The average of the two red signals at the left and right positions adjacent to the interpolation position, or the average of the four red signals at the diagonally up, down, left and right positions of the interpolation position. 3. The color still image rapid imaging apparatus according to claim 1, wherein the color interpolation of the signal is performed, and the color interpolation of the blue signal is performed similarly to the color interpolation of the red signal. 4. The color interpolation means performs color interpolation of a green signal by averaging four green signals at upper, lower, left and right positions adjacent to an interpolation position, and performs a color interpolation of a green signal at an interpolation position and an adjacent green signal at the interpolation position. The ratio between the green signal at the position and the red signal at the position adjacent to the interpolation position is multiplied by the color interpolation of the red signal at the interpolation position, and the color interpolation of the blue signal is performed in the same manner as the color interpolation of the red signal. The color still image rapid imaging apparatus according to claim 1 or 2, wherein: 5. The method according to claim 1, wherein the color interpolation is performed at two positions above and below the interpolation position.
The difference D1 between the two green signals and the difference D2 between the two green signals on the left and right of the interpolation position are calculated, and when there is a difference between the difference D1 and the difference D2 that is equal to or greater than a preset value, the smaller difference is used. The two green signals are averaged, color interpolation of the green signal is performed, and the difference D1 is calculated.
When there is no difference between the red signal at the interpolation position and the red signal R vertically adjacent to the interpolation signal, the difference D3 between the red signal at the interpolation position and the red signal horizontally adjacent to the red signal at the interpolation position. When the difference D3 is smaller than the difference D4, the green signals above and below the interpolation position corresponding to the vertical difference D3 are averaged to perform color interpolation of the green signal. In the following cases, the left-right difference D4
3. The color still image rapid imaging apparatus according to claim 1, wherein the color signals of the green signals are averaged by averaging the green signals on the left and right of the interpolation position corresponding to (1). 6. The color still image rapid imaging apparatus according to claim 1, wherein the movement of the pixel shift is performed by repeating a reciprocating movement in a horizontal or vertical direction.