JPH0543583Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a video signal recording/reproducing device, and more specifically, the present invention is suitably implemented in a video tape recorder, a video disc player, etc. having a still image function, and has a low flicker. The present invention relates to a video signal recording/reproducing device that realizes still images.

Prior Art A typical conventional video tape recorder having a still image function stores one frame of video in a memory and plays it back. In such conventional technology, when a fast-moving video is played back, the above-mentioned 1.
Since there is a shift between the images of the two fields that make up the image of the frame, flickering occurs in the reproduced still image.

In other prior art video tape recorders that solve this problem, one field of video is stored in a memory, and one frame of video is constructed by repeatedly reading out the stored one field of video. In such conventional techniques, the video information is halved, resulting in a problem in that the resolution is significantly reduced.

Problems to be solved by the invention The purpose of the invention is to obtain a still image with less flickering by repeatedly reading out one field of video and composing one frame of video for relatively fast-moving images. To provide a video signal recording/reproducing device which can obtain still images of good resolution by reading out one frame of video for videos with relatively little movement. That's true.

Means for Solving the Problems The present invention provides storage means for storing video signals for each field period, and two fields in the same frame.
Comparison means for mutually comparing the video signals in the two fields, wherein two adjacent video signals in the odd field
averaging means for obtaining an average value of the video information included in the two scanning lines; and an output from the averaging means and the video information included in the even field scanning line sandwiched between the two scanning lines are determined in advance. binarization means that binarizes the outputs of the two binarization means, and a comparator that mutually compares the outputs from the two binarization means; a counter that performs a counting operation in response; a determining means that determines whether the video signals between the two fields match by comparing the counted value of the counter with a predetermined set value; In response to the output of the determining means, when it is determined that the video signals match between the two fields, 2.
The present invention is a video signal recording/reproducing device characterized in that it includes reading means for reading video signals of two fields and, when a mismatch is determined, repeatedly reading video signals of temporally preceding fields.

Effect According to the present invention, the video signal is stored in the storage means for each field period, and the video information included in each scanning line of the video signal is compared by the comparison means between two images in the same frame. The fields are compared to each other.

The comparing means includes an averaging means, a binarizing means, and a comparator. The average value of the video information is determined and binarized by the binarizing means at a predetermined discrimination level. Further, the video information of the even field scanning lines sandwiched between the two scanning lines is also binarized by the binarizing means. The video information thus binarized is compared with each other by a comparing means. As a result of the comparison, when the video information included in each scanning line matches each other between the two fields, the counter performs a counting operation, and the counted value is compared with a predetermined set value by the discriminating means. Ru.

As a result of the comparison by the discriminating means, when the counted value is equal to or greater than the set value, that is, when the video has relatively little movement, the video signals of the two fields are read out alternately from the storage means, and therefore good resolution is obtained. You can get still images. Also 2
When the color signals between fields do not match, that is, when the video is moving relatively quickly, the video signal of the temporally preceding field is repeatedly read out from the storage means, so that a still image without flickering can be obtained. Can be done.

Embodiment FIG. 1 is a block diagram showing the electrical configuration of an embodiment of the present invention. This video signal recording/reproducing device is used in a video tape recorder having a still image function. The analog video signal input to the input terminal 1 is demodulated by the decoder 2 into color signals R, G, and B of the three primary colors, and then converted into color signals R, G, and B of the three primary colors.
Digital conversion is performed in analog/digital (A/D) converters 3, 4, and 5 provided individually for each B.

The digitally converted red color signal R1 is given to an odd field memory 6a and an even field memory 6b (6 when collectively referred to as storage means), and similarly, a green color signal G1 is given to an odd field memory 6a and an even field memory 6b (6 when collectively referred to as 6). The blue color signal B1 is applied to an odd field memory 9a and an even field memory 9b (9 when collectively referred to as 9).

The output terminal of the odd field memory 6a is connected to an individual contact 12 of a changeover switch 11 which is a reading means, and the output terminal of the even field memory 6b is connected to an individual contact 13. The switching mode of this changeover switch 11 changes according to the changeover control signal from the line 14, and therefore, the common contact 15 outputs color signals R1a, R1a, and R1a from the memory 6a for the odd field and the memory 6b for the even field.
R1b is selectively read out, converted into an analog signal by a digital/analog (D/A) converter 16, and delivered to an output terminal 17.

Similarly, the output terminal of the odd field memory 7 is connected to the individual contact 22 of the changeover switch 21,
The output terminal of memory 8 for even field is an individual contact.
23, the color signal G1a from the common contact 25,
G1b is led out to an output terminal 27 via a digital/analog converter 26. The output terminal of the odd field memory 9a is connected to the individual contact 32 of the changeover switch 31, the output terminal of the even field memory 9b is connected to the individual contact 33, and the color signals B1a and B1b from the common contact 35 are digital/analog. It is led out to an output terminal 37 via a converter 36.

The video signal from the input terminal 1 is also given to the sync separation circuit 41. This synchronous separation circuit 41 is
A horizontal synchronizing signal is derived from a line 42, and a vertical synchronizing signal shown in FIG. The field discrimination circuit 44 is constituted by, for example, a flip-flop, and as shown in FIG. 2, outputs a low level output to the line 49 when the field is an odd number field, and outputs a high level output when the field is an even number field. Derive.
The field discrimination signal from the field discrimination circuit 44 is applied to the memories 6-9, respectively, and the write and read operations of the memories 6-9 are synchronized.

The field discrimination signal is also input to the individual contact 46 of the changeover switch 45, the individual contact 47 of this changeover switch 45 is grounded, and the common contact 48 is connected to the line 14.
connected to. Therefore, this changeover switch 45
When the common contact 48 is conducting to the individual contact 46, the switching control signal led out to the line 14 is the field discrimination signal shown in FIG. In this case, the common contacts 15, 25, 35 of the changeover switches 11, 21, 31 are the individual contacts 12, 22, 32, respectively.
conducts to the odd field memories 6a, 7, 9.
The color signals R1a, G1a, and B1a stored in a are read out. During the period when the field discrimination signal is at high level, the common contacts 15, 25, 35 of the changeover switches 11, 21, 31 are connected to the individual contacts 13, 35, respectively.
23, 33, even field memory 6b,
Color signals R1b, G1b, B stored in 8, 9b
1b is read. Furthermore, when the common contact 48 of the changeover switch 45 is electrically connected to the individual contact 47, the changeover control signal remains at low level, and therefore, the changeover control signal remains at low level, and the changeover control signal remains at low level. Common contacts 15, 25, 35 of 11, 21, 31 are electrically connected to individual contacts 12, 22, 32, and color signals R1a, G1a, B1a stored in odd field memories 6a, 7, 9a are read out.

The movement of the subject on the video signal input from input terminal 1, that is, the video information included for each scanning line of an adjacent odd field, and the video information included for each scanning line of an even field corresponding to each scanning line of this odd field. Comparison means are provided to mutually compare the included video information. The comparison means includes an averaging means constituted by a line memory 51, an arithmetic unit 52, and a field memory 64, and a binary level input circuit 73 constituted by binarization circuits 71, 72 and a binarization level input circuit 73. It is configured to include a value converting means and a comparator 53.

Video information f(m,n) of the m-th scanning line is supplied to the line memory 51 from the odd field memory 7 via the line 54. (m=1,
2, 3...262, n=1, 2, 3... However, the maximum value of n is the number of pixels per scanning line. ) The output terminal of the odd field memory 7 is also connected via a line 55 to one input terminal of an arithmetic unit 52, and the other input terminal of this arithmetic unit 52 is connected via a line 56 to a line memory 7. The output from 51 is given. In this way, the line memory 51
The video information f(m,n) of the m-th scanning line delayed by one horizontal scanning period is input to the other input terminal of the arithmetic unit 52 via the line 56. One input terminal has line 5
5, the video information f of the m+1th scanning line
(m+1,n) is input.

The arithmetic unit 52 calculates two pieces of video information f(m,n), f
The average value F(m,n) of (m+1,n) is calculated based on the formula below and is provided to the field memory 64. This field memory 64 stores the average value F(m,n)
is delayed by approximately one field period and is applied to the binarization circuit 71.

F(m,n)=f(m,n)+f(m+1,n)/2
(1) The binarization circuit 71 binarizes the input signal from the field memory 64 according to the discrimination level set in advance by the binarization level input circuit 73, and compares it via the line 57. is applied to one input terminal of the device 53. The other input terminal of the comparator 53 receives the video information g(m,n) of the m-th scanning line in the even field from the even field memory 8.
After being binarized in the binarization circuit 72, it is input via the line 58.

The comparator 53 determines whether or not these two pieces of input information match, that is, there is a difference between the video information for each scanning line of the odd field and the video information for each scanning line of the corresponding even field. If not, a pulse is given to the counter 60 via line 59.

The counter 60 counts these pulses and provides the counted value to a comparator 61 which is a determining means. The comparator 61 compares the counted value of the counter 60 with a set value inputted in advance by the set value input means 63, and when the set value is exceeded, that is, there is no deviation in the images between both fields, the line is A low level output is derived from the switch 62, and the common contact 48 of the changeover switch 45 is electrically connected to the individual contact 46. Further, when there is a deviation, the line 62 is set to high level, and the common contact 48 of the changeover switch 45 is electrically connected to the individual contact 47.

Therefore, as mentioned above, when there is a discrepancy between the images of the odd field and the even field, the line 62 goes high, which causes the switching control signal on the line 14 to go low, and the changeover switch is turned off. Common contacts 15, 25, and 35 of 11, 21, and 31 are electrically connected to individual contacts 12, 22, and 32, respectively, and video signals of temporally preceding odd fields are repeatedly read out, making it possible to obtain flickering-free still images. can. Further, when there is no deviation between the video of the odd field and the video of the even field, the line 62 becomes low level, and a field discrimination signal is derived as a switching control signal on the line 14, and the changeover switches 11, 21 ，
31 common contacts 15, 25, and 35 are each individual contacts
12, 22, and 32 and the individual contacts 13, 23, and 33 are alternately electrically connected, and video signals of odd-numbered fields and video signals of even-numbered fields are read out alternately, making it possible to obtain a still image with good resolution.

Further, the criterion for determining whether there is a difference between the odd field video and the even field video can be changed relatively easily by changing the setting value inputted in advance to the setting value input means 63. be able to. Therefore, the discrimination criteria may be changed in accordance with the image quality of the video signal input to the input terminal 1.

FIG. 3 is a block diagram showing the electrical configuration of another embodiment of the present invention, which is similar to the previous embodiment and corresponding parts are given the same reference numerals. In this embodiment, an analog video signal input to an input terminal 1 is demodulated into a luminance signal Y and color difference signals R-Y, B-Y in a decoder 2a, and then each signal Y, R-Y, B-Y is demodulated into a luminance signal Y and color difference signals R-Y, B-Y. - Digital conversion is performed in analog/digital (A/D) converters 3, 4, and 5 provided individually for each Y.

The digitally converted color difference signal (R-Y) ₁ is given to an odd field memory 6a and an even field memory 6b (generally referred to as 6), which are storage means, and similarly, the luminance signal _Y1 is The color difference signal (B-Y) 1 is applied to an odd field memory 7 and an even field memory 8, and a color difference signal (B-Y) ₁ is applied to an odd field memory 9a and an even field memory 9b (generally referred to as 9).

The output terminal of the odd field memory 6a is connected to an individual contact 12 of a changeover switch 11 which is a reading means, and the output terminal of the even field memory 6b is connected to an individual contact 13. This changeover switch 11
The switching mode changes depending on the switching control signal from line 14, and therefore the common contact
From 15 on, color difference signals (R-Y) from the odd field memory 6a and the even field memory 6b
_a and (RY) _b are selectively read out, converted into analogs by a digital/analog (D/A) converter 16, and output to an output terminal 17.

Similarly, the output terminal of the odd field memory 7 is connected to the individual contact 22 of the changeover switch 21, and the output terminal of the even field memory 8 is connected to the individual contact 23.
and the brightness signal Y ₁ a from the common contact 25,
Y ₁ b is led out to output terminal 27 via digital/analog converter 26 . The output terminal of the odd field memory 9a is connected to the individual contact 32 of the changeover switch 31, the output terminal of the even field memory 9b is connected to the individual contact 33, and the color difference signal (B-Y) _a , from the common contact 35 is connected. (B-Y) _b is led out to the output terminal 37 via the digital/analog converter 36. The other configurations are the same as the embodiment shown in FIG.

In the above embodiment, whether there is a lot of movement of the subject on the video signal is determined based on the green color signal G1 or the luminance signal _Y1 . , B1 or color difference signals (RY) ₁ , (BY) ₁ may be used.

Effects As described above, according to the present invention, when the video signals of two fields in the same frame match each other, that is, when the video has relatively little movement, the video signals of the two fields alternate. Therefore, a still image with good resolution can be obtained. Furthermore, when the video signals between two fields do not match, that is, when the video is moving relatively quickly, the video signal of the temporally preceding field is repeatedly read out, making it impossible to obtain a flicker-free still image. can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the electrical configuration of one embodiment of the present invention, FIG. 2 is a waveform diagram for explaining the operation, and FIG. 3 is a block diagram showing the electrical configuration of another embodiment of the present invention. It is a diagram. 2, 2a... Decoder, 3, 4, 5... Analog/digital converter, 6a, 7, 9a... Memory for odd field, 6b, 8, 9b... Memory for even field, 11, 21, 31, 45...Selector switch, 16, 26, 36...Digital/analog converter, 41...Synchronization separation circuit, 44...
Field discrimination circuit, 51...Line memory, 5
2... Arithmetic unit, 53, 61... Comparator, 60...
Counter, 63... Setting value input means, 64... Field memory, 71, 72... Binarization circuit, 7
3...Binarization level input circuit.

Claims (1)

[Claims for Utility Model Registration] Storage means for storing video signals for each field period, and two fields in the same frame,
Comparison means for mutually comparing the video signals in the two fields, wherein two adjacent video signals in the odd field
averaging means for obtaining an average value of the video information included in the two scanning lines; and an output from the averaging means and the video information included in the even field scanning line sandwiched between the two scanning lines are determined in advance. binarization means that binarizes the outputs of the two binarization means, and a comparator that mutually compares the outputs from the two binarization means; a counter that performs a counting operation in response; a determining means that determines whether the video signals between the two fields match by comparing the counted value of the counter with a predetermined set value; In response to the output of the determining means, when it is determined that the video signals match between the two fields, 2.
1. A video signal recording/reproducing device comprising: reading means for reading video signals of two fields and, when a mismatch is determined, repeatedly reading video signals of temporally preceding fields.