JPH078054B2 - Color difference line sequential video signal processor - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color-difference line-sequential video signal processing system.

BACKGROUND ART For example, in an image pickup system using a solid-state image pickup element in which color filter segments of three primary colors of red, green, and blue are sequentially arranged for each horizontal scanning, and two primary colors among them, red and green, or blue and green are sequentially arranged. , A color signal not included in one horizontal scan is obtained by delaying the signal of the horizontal scan immediately before it by one horizontal period. For example, n
The colors of the color filter segments on the solid-state imaging device that obtain the signal of the scanning line of the line are red and green, and the respective red and green color signals obtained by scanning are R _n and G _n . At this time, since the color signal by the blue light cannot be obtained in real time, the blue color signal B _n-1 at the time when the scanning signal of the n-1th line before that is obtained
Is delayed by one horizontal scanning period and used.

With these, the process circuit processes the video signal and outputs the luminance signal of the _{n- th} scanning line to Y (R _n , G _n , B _n-1 ) = 0.3R _n + 0.59G
Obtained from _n + 0.11B _n-1 . However, in the conventional method, for example, the color difference signal of the scanning line of the nth line is
There is no guarantee that the circuit will be switched to obtain the color difference signal R _n -Y by using the color signal R _n of the scanning line of the line n-1,
The circuit may be switched so that the color difference signal B _n-1 -Y is generated by the color signal B _n-1 of the line.

In this case, the color difference signal of the _n- th line is B _n-1 −Y (R _n , G _n ,
B _n-1 ), which is mainly formed by the blue signal B _n-1 of the _n- 1th line, there is a drawback that when the signal is displayed on the display device, a color shift occurs.

It is an object of the present invention to provide a color difference line sequential video signal processing method capable of solving such drawbacks of the prior art and obtaining a high quality image with no color shift.

DISCLOSURE OF THE INVENTION According to the present invention, the single color solid-state image sensor outputs the first color signal for each horizontal scanning image, and the second signal and the blue signal (for specifying the red signal (R) are specified. B)
And a third signal for specifying the above is delayed for one horizontal scanning period, and a through signal which is not so is switched for each horizontal scanning period and simultaneously output to obtain color signals of three colors.
The color signals of the three colors are subjected to signal processing to obtain a luminance signal (Y) and two kinds of color difference signals (RY) and (BY), and further, the two kinds of color difference signals (RY) and (Y). B-Y) corresponding to the second signal and the third signal obtained as the through signal in the color signal synchronization, and selected and output for each horizontal scanning period. It is a sequential video signal processing method.

Description of Embodiments An embodiment of a color difference line sequential video signal processing method according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic overall configuration diagram of an image pickup system for explaining the present embodiment. In this embodiment, a video signal FM from an image pickup system is modulated and recorded. In the figure, a light flux from an unillustrated object passes through the image lens 1 and forms an image on the image pickup surface of the solid-state image pickup device 3 having the mosaic color filter 2 on the image plane. The drive circuit 4 is for driving the solid-state image sensor 3, and the color separation circuit 5 separates the color signal from the solid-state image sensor 3 into a green signal G and red, blue signals, and R and B in this embodiment. The delay circuit 6 sequentially delays the red and blue signals (R and B) by one horizontal scanning period. The switch 7 is switched for each horizontal scanning, and in order to output the red or blue signal (R or B) output through, and the blue or red signal (B or R) delayed by the delay circuit 6 for one horizontal scanning period. It is provided.

The process circuit 8 forms the luminance signal Y by, for example, the formula Y = 0.3R + 0.59G + 0.11B based on the green signal G input from the color separation circuit 5 and the red and blue signals (R and B) input from the switch 7. And outputs the color difference signals RY, B
-Y is output. The switch 9 switches every horizontal scanning, and the color difference signals RY, B- output from the process circuit 8 are switched.
Alternately select Y.

The FM modulator 11 modulates the luminance signal Y, and the FM line-sequential modulator 12 FM-modulates either the color difference signals RY or BY output from the switch 9 alternately for each horizontal scanning.

The signal from the drive circuit 4 is input to the synchronization switching circuit 10,
As a result, the switches 7 and 9 are switched in synchronization with each other. That is, the through signal selected by the switch 7 for switching the signal delayed by one horizontal scanning period by the delay circuit 6 and the through signal other than the same for each horizontal scanning period (timing shown in FIG. 1). In this case, the switches 7 and 9 are switched in synchronization so that the switch 9 selects the color difference signal (R-Y at this timing) corresponding to the R signal.

FIG. 2 shows a front partial view of the mosaic color filter shown in FIG. 1. The symbol R is a red filter segment that transmits only red light, the symbol G is a green filter segment, and the symbol B is a blue filter segment. , Only blue light is transmitted, and it is a Bayer array. n is the horizontal scanning of the nth line, n + 1, n−1, ... Is the n + 1th line, n−1
The horizontal scanning of the line ... Is shown respectively. FIG. 3 shows the signals obtained during scanning. For example, G _n and R _n of the line number n are color signals obtained when the horizontal scanning of the nth line is performed, and a line signal corresponding to the line number n outputs a through signal as R _n. The signal delayed in the horizontal scanning period is output as B _n-1 .

The operation will be described with reference to FIGS. 1 to 3. n
In the horizontal scanning of the line, the green signal G _n and the red signal R _n are output from the solid-state image sensor 3, and the color separation circuit 5 outputs the green signal G _n and the red signal.
It is separated into R _n and. In this horizontal scanning period, the delay circuit 6 outputs the blue signal B _n-1 one horizontal scanning period before, that is, the n-1th line.

At the time of horizontal scanning of the nth line, the switch 7 is switched to the upper side by the synchronous switching circuit 10 as shown in FIG. ₁ to input the blue signal B _n-1 and the red signal R _n to the process circuit 8. ing. Further, the process circuit 8 inputs the through green signal G _n which is color-separated.

These process circuit 8 horizontal scanning periods of the n-th line, the luminance signal _{Y (R n, G n,} B n-1) = 0.3R n + 0.59G
_n + 0.11B _n-1 and color difference signal B _n-1 -Y (R _n , G _n , B _n-1 ), R _{n
-Y (R n, G n,} B n-1) and outputs a. Therefore, the n
At the time of horizontal scanning of the line, as shown in FIG. 1, the synchronization switching circuit 10 synchronizes with the switch 7 and switches the switch 9 to the color difference signal.
_{R n -Y (R n, G} n, B n-1) Since the switching to the side to obtain,
The color difference signal RY corresponding to the red signal R _n obtained through
It is sent to the recording device 13 via the FM modulator 12.

Next, in the horizontal scanning of the (n + 1) th line, the blue signal B _{n + 1} and the green signal G _{n + 1} are output from the solid-state image sensor 3, and the color separation circuit 5
Are separated into a green signal G _{n + 1} and a B signal B _{n + 1} . In this horizontal scanning period, the delay circuit 6 outputs the red signal R one horizontal scanning period before, that is, the nth line.

The signal output in this manner has the switches 7 and 9 switched to the opposite positions by the synchronization switching circuit 10, so that the process circuit 8 is operated based on the same operation as described above.
, The luminance signal Y (R _n ,
G _{n + 1} , B _{n + 1} ) = 0.3R _n ＋0.59 G _{n + 1} ＋ 0.11B _{n + 1} and color difference signal R
_{n -Y (R n, G n} + 1, B n + 1), B n + 1 -Y (R n, G n + 1,
B _{n + 1} ) is output, and the color difference signal RY corresponding to the blue signal obtained through the switch 7 is output to the recording device 13 via the FM modulator 12.

By repeating the above for each horizontal scanning, a color difference signal corresponding to a red or blue color signal obtained through from the solid-state image pickup device 3, RY or BY, a luminance signal via the FM modulator 12. Since it is given to the recording device 13 together with Y, no recording that causes color misregistration occurs.

In the present invention, a second signal for specifying the red signal (R) is used.
The signal of is not necessarily the red signal itself,
A signal that is the basis for producing the color difference signal RY in the subsequent process circuit, for example, a yellow signal (Ye: G + R) may be used,
Similarly, the third signal for specifying the blue signal (B) may also be cyan (Cy: G + B), for example.

Effect In the present invention, a color difference signal corresponding to the color signal obtained through is obtained and recorded or displayed, so that a good color image can be obtained without causing color shift.

[Brief description of drawings]

FIG. 1 is a schematic overall configuration diagram of an example of an image pickup system for explaining an embodiment of the present invention, FIG. 2 is a partial front view showing an array state of the design color filters used in FIG. 1, and FIG. [Fig. 4] is a diagram showing signals obtained in each scanning. Explanation of symbols of main parts 2 ... Mosaic color filter 3 ... Solid-state image sensor 4 ... Drive circuit 7, 9 ... Switch 10 ... Synchronous switching circuit

Claims (1)

[Claims] 1. A synchronizing signal generating means for generating and outputting a driving synchronizing signal, and a green signal (G) for each horizontal scanning based on the driving synchronizing signal from the synchronizing signal generating means. Of the second color signal for specifying the red color signal (R) and the third color signal for specifying the blue color signal (B) every other horizontal scanning. A signal supply unit including a solid-state imaging device having a color filter having a signal array to be output, and based on the drive synchronization signal from the synchronization signal generation unit,
Synchronization for outputting a switching signal for switching corresponding to the second color signal for specifying the red signal (R) and the third color signal for specifying the blue signal (B) output from the signal supply means Switching means; delay means connected to the signal supply means for sequentially delaying the second and third color signals alternately supplied from the signal supply means for each horizontal scanning by one horizontal scanning period; A signal line connected to the signal supply unit for sequentially outputting the second and third color signals alternately supplied from the signal supply unit for each horizontal scanning without delay, Selective means for selecting the delayed output and the delayed output from the delay means by the switching signals from the synchronous switching means to synchronize the second and third color signals, and is supplied from the signal supply means. Second and third The the non-delayed output from the signal line for each horizontal scan in response to the color signals and the delayed output from the delay means second
And selecting means for alternately switching as the third color signal, the second and third color signals from the delayed output and the non-delayed output selected by the selecting means, and the first signal from the signal supplying means. Signal processing means for simultaneously receiving and processing the color signals of the three colors to generate a luminance signal (Y) and two types of color difference signals (RY) and (BY), and from the signal processing means Of the second color signal, the two types of color difference signals (RY) and (BY) from the signal processing means are obtained as non-delayed signals when the selecting means is synchronized. Color difference line sequential video signal processing, characterized in that the color difference line sequential video signal processing comprises: output means for alternately selecting the color signal and the third color signal every horizontal scanning period by the switching signal from the synchronous switching means and outputting the selected signals. apparatus.