JPS59212094A - Digital picture recording device - Google Patents

Abstract

PURPOSE:To obtain an enough S/N ratio as compared with recording in the form of signals Y, U, and V by sampling color signals of three primary colors at sampling frequencies corresponding to the amounts of data, and recording sampled signals. CONSTITUTION:A sample output of G obtained from an image sensor 1 and a time-division sample output of R and B obtained from an image sensor 2 are supplied to A/D converters 3 and 4 respectively and converted into one-sample, eight-bit digital signals. Those outputs are supplied to a multiplexer 5, which composes data of one channel. The output of this multiplexer 5 is passed through an error correcting encoder 6 and a channel encoder 7 to perform error correcting and encoding processing and block coding processing, and the resulting signal is supplied to a rotating head 9 through a recording amplifier 8 and a rotary transformer 9 to be recorded on a magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a digital image recording device that is applied when, for example, the output of a color imaging device using COD is recorded on a magnetic tape by a rotary head.

"Background Art and its Problems" When digitizing a color video signal, there is a composite coding method for digitizing a composite color video signal, and a component coding method for coding each component of the luminance signal Y and color difference signals U and V. There is a method. The component encoding method shall not be affected by differences in color television systems such as NTSC and PAL.

It is superior to composite encoding systems in that it can be used as is as a signal source for digital image processing devices such as digital chromakey devices. The component coding method uses (4, 2
, 2) method, (2°1.1) method, etc.

The components Y, U, V (or Y, I, Q) that are the targets of this component encoding are:

1 sample 8 formed by calculating the primary color signals R, G, and B
It has bit precision. and.

A signal in which (Y, U, V) is component encoded using the (4,2,2) method has insufficient accuracy as a signal source for digital chroma key.

What is the relationship between the luminance signal, color difference signal, and three primary color signals?

It is expressed by the following formula.

Y=0.3R+0.59G+0.11 BV=RY=
0.7R-0, 59G-0, IIBU=B-Y=-0,
3R-0,59G+0.89BHere, when the color signals R, o, and B of the three primary colors are 8 bits, the number of F required to make full use of the precision of each is determined.

Y=10Y≠3'R+60+IB≠2・2 +23・2
+2= (22+23+1.) ・2= (4+8+
1) ・2=13.28 <24.28=12 (bits) Furthermore, if 1 bit of the sign is added, 1 originally requires 13 bits. This is one color difference data U.

The same applies to ■. However, since this is compressed to 8 bits, 5 bits of S/N information are lost, and this is insufficient as a signal source for a digital chromakey device.

``Object of the Invention'' The present invention avoids the problems caused by converting into (Y, U, V) components by directly recording the three primary color signals R, G, and B.

The present invention also provides component encoding methods such as (
Using a digital VTR capable of recording data using the 4,2,2) method, (G, R, B) = (4,2,2)
) It is possible to configure a component digital VTR with the system.

"Summary of the Invention" This invention provides a system in which color signals of three primary colors are supplied, each color signal is sampled at a sampling frequency corresponding to the amount of data, and the sampled color signals are recorded on a recording medium. It is something.

"Embodiment" An embodiment in which the present invention is applied to the case of recording the imaging output of a CCD camera will be described. FIG. 1 shows the configuration of a recording system, in which numerals 1 and 2 are image sensors consisting of CCDs.

The image sensor 1 is as shown in FIG. 2A.

A color filter is provided for all pixels to pass green color light, and the imaging output of this image sensor 1 is a continuous sample output of G (green). Further, as shown in FIG. 2B, the image sensor 2 has a COD
A color filter that allows red color light to pass through and a color filter that allows blue color light to pass are arranged in a checkerboard pattern on the light receiving surface of the light receiving surface. Corresponding to this color arrangement, the output of the image sensor 2 is as follows.

This is a time-division signal in which R (red) and B (blue) sample data are alternately present. The horizontal and vertical intervals of one pixel between image sensors 1 and 2 are equal, and the sampling frequency of the G signal is set to 4fO(
fo is a predetermined frequency), then the sampling frequency of the R and B signals is.

2fo becomes (C), R, B) = (4,
2,2).

The outputs of the image sensors 1 and 2 are supplied to A/D converters 3 and 4, respectively, and are converted into digital signals of 8 bits per sample.
The output of is supplied to multiplexer 5. This multiplexer 5 converts the outputs of the A/D controllers 3 and 4 into 1
It is combined with channel data, and the output of multiplexer 5 is (G.

R, G, 'B, G, R, G, 'E...
) and time-division multiplexed digital color data appear.

The output of this multiplexer 5 is supplied to an error correction encoder 6 and subjected to error correction encoding processing.

Furthermore, the channel encoder 7 performs, for example, block coding processing. The signal is then supplied to a rotary head 10' via a recording amplifier 8 and a rotary transformer 9, and is recorded on a magnetic tape by this rotary head 10.

The signal reproduced from the magnetic tape by the rotary head 10 is supplied to the channel decoder 13 via the one-rotation transformer 9 and the reproduction amplifier 12, and is returned to the original digital signal. Then, errors during recording and reproduction are corrected by the error correction decoder 14, and uncorrectable errors are interpolated and supplied to the demultiplexer 15. This demultiplexer 15 (thereby separates each sample into 8-bit digital color data G, R, and B).

This digital color signal G is supplied to the D/A converter 1'8G via the delay circuit 16, and the digital color data R and B are supplied to the interpolation filter 17.

This is because digital color data R and B have half the amount of data compared to digital color data G.

Interpolation filter 17 forms interpolated data. The delay circuit 16 has a delay time to compensate for the time delay occurring in the interpolation filter 17. Interpolation filter 1
The outputs of 7 are supplied to D/'A converters 18R and 18B, respectively. These D/A converters 18(), 18
The respective outputs of R and 18B are output terminals 19G, 19R, 1
It is taken out at 9B. This D/'A converter 18G,
The digital data may be taken out as an output without providing 18R and 18B. Furthermore, component data Y, U are generated using the reproduced primary color signals R, G, , B.

(2), and this component data can be used as a signal source for a digital chromakey device.

This invention is an image sensor using a one-chip CCD.
Another embodiment applied to the case of recording the output will be described. FIG. 4 shows the configuration of a recording circuit according to another embodiment of the present invention, in which 21 is an image sensor. As shown in FIG. 5, this image sensor 21 has a color filter provided on the light receiving surface of the COD.

In other words, regarding three consecutive lines (n-1), n, and (n+1) of the first field of the image sensor 21, GR
Each color filter is repeated in units of GB, and
The array is shifted between each line by two picture elements. Also, the second
In the adjacent lines spatially below these lines in the field.

The array of color filters in units of GRGB is shifted by one pixel. Therefore, the colors of the nine-color filter are arranged diagonally from the upper left to the lower right. Such a color arrangement allows good interpolation of the nine fish signals R and B.

The imaging output of the image sensor 21 is supplied to the A/D converter 22 and converted into one sample 8-bit digital data. G of the imaging output of the image sensor 21,
If the sampling frequency when summing up all of R and B is 4, then (C), R, B) = (2, 1, 1). This is (Y.

This corresponds to the method U, V) = (2, 1, 1).

The output signal of the A/D converter 22 is sent to the error correction encoder 2.
3, it undergoes error correction encoding processing.

Further, the signal is supplied to a rotary head 27c' via a channel encoder 24, a recording amplifier 25, and a rotary transformer 26, and is recorded on a magnetic tape.

FIG. 6 shows a reproduction system according to another embodiment of the present invention.

The reproduction signal extracted by the rotary head 27 is supplied to a channel decoder 30 via a one-rotation transformer 26 and a reproduction amplifier 29. The output of this channel decoder 30 is supplied to an error correction decoder 31, and the corrected data is supplied to a demultiplexer 32.
.

B is separated and supplied to the interpolation filter 33.

Continuous one-sample 8-bit color data appears at the output of the interpolation filter 33, and the D/A converter 34
Output terminals 35G and 35R are converted to analog signals by G, 34R and 34B.

It is taken out at 35B.

“Application Example” This invention is applicable to R output from a single-tube color imaging device.
It can be applied when recording G,,'B output. In addition, a camera integrated type V in which the imaging section and the recording section are integrated
This invention may also be applied to TR.

"Effects of the Invention" According to this invention, in FIG. 7, all the signals G', , R, and B are sampled at the sampling points indicated by black dots, and the G signal is sampled at the sampling points indicated by white dots. Because it is sampled.

The 8-bit accuracy of each of R, G, . . . B can be utilized to form Y, U, and V component signals. Therefore, 8 bits Y, U.

■Compared to the conventional one that converts to a signal and records it.

It can have sufficient S/N. Therefore, it can also be used as a signal source for a digital chromakey device.

In addition, this invention can record signals in which o, R, and B signals are time-divided, such as the output of a CCD image sensor, with almost no signal processing, simplifying the circuit configuration and reducing power consumption. can be realized.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a recording circuit according to an embodiment of the present invention.
FIG. 2 is a route map showing the color arrangement of an image sensor according to an embodiment of the present invention, FIG. 3 is a block diagram of a reproduction circuit according to an embodiment of the present invention, and FIGS. FIG. 6 is a block diagram of a reproducing circuit according to another embodiment of the present invention, and FIG. 7 is an explanation of the sampling method of the present invention. It is. 1.2.21... Image sensor, 5...
...Multiplexer, 10.27... Rotating head. 15.32...Demultiplexer, 17.33
......Interpolation filter. Agent: Tomo Sugiura 550-

Claims (1)

[Claims] A digital image recording device that is supplied with color signals of three primary colors, samples each color signal at a sampling frequency corresponding to the amount of data, and records the sampled color signals on a recording medium.