JPH0787457A - Method for discriminating video signal system and video signal processing unit using the method - Google Patents

Abstract

PURPOSE:To automatically discriminate the inputted video signal system with a simple measurement by measuring one vertical scanning period of an input video signal with a clock pulse whose frequency is known and measuring the number of horizontal scanning lines for two consecutive vertical scanning periods. CONSTITUTION:One vertical scanning period of a vertical synchronizing signal fV is counted by a clock pulse whose frequency is known and let the count value be VC, then the vertical scanning frequency is (frequency of the clock pulse)/VC and the VC is used to represent the vertical scanning frequency. Furthermore, the number of horizontal scanning lines of two consecutive vertical scanning periods is counted and let them be L1, L2 respectively, then in the case of L1=L2, the video signal is a noninterlaced signal and in the case of L1not equal to L2 and L1-L2=+ or -1, the signal is an interlaced signal. Moreover, the horizontal scanning frequencies are a time of L1/one vertical scanning period and a time of (L1+L2)/2X one vertical scanning period respectively, then they are expressed by the counts L1, L1+L2, and the system is specified by the value VC and the counts L1, L2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of discriminating an input video signal system and a video color printer (hereinafter, referred to as "VCP") which automatically operates in conformity with a video signal system input by using this method. And a video signal processing device such as a multi-scan monitor.

[0002]

2. Description of the Related Art An example of VCP will be described below. In the conventional VCP, when a color image or the like displayed on a display device is hard-copied, the color image signal is converted into digital data and stored in a memory.
It is a general method to sequentially read data from this memory and print it. The reason why the image is once stored in the memory is that it takes several minutes for color copying.

When storing color image data in a memory, various parameters of the video signal system, that is, horizontal scanning frequency, horizontal scanning line number and vertical scanning frequency are required. This is because different parameters require different memory capacities. Therefore, in the conventional VCP, in order to determine the video signal system, a name meaning the whole, for example, PC9801 system, VGA
System, SVGA system (800 x 600 Std system, 1024 x 768 Std system, 1280 x
1024 system), Macintosh II system,
By assigning the names such as, and specifying the names by key operation, various parameters of the video signal system are collectively called to set the operating conditions of the VCP.

[0004]

In the conventional VCP, it is necessary to reset the parameters to be operated each time the video signal system to be printed is changed, so that the operation is troublesome.
There is also a problem that the parameter cannot be set unless the user is aware of the parameter of the input video signal system.

The present invention has been made for the purpose of solving the above problems, and provides a method capable of determining an input video signal system by performing a simple measurement.
Another object of the present invention is to obtain a video signal processing device that can automatically set parameters in a state suitable for an input video signal system by using this determination method.

[0006]

According to a method of discriminating a video signal system according to the present invention, one vertical scanning period of an input video signal is measured by a clock pulse having a known frequency, and horizontal scanning lines of two consecutive vertical scanning periods are measured. The number is counted, and the type of the input video signal system is discriminated from these data.

Further, in the video signal processing device according to the present invention, in the video signal system to be discriminated, the number of clock pulses in one vertical scanning period measured by the discriminating method and one vertical scanning period for the non-interlaced signal. Regarding the number of horizontal scanning lines and the number of interlaced signals, the number of horizontal scanning lines in two consecutive vertical scanning periods is stored in a memory for each system, and a video signal that matches each measured data of the input video signal counted by the above-mentioned discrimination method. A system is selected, and when they do not match, an approximate video signal system is selected to set the operating condition of the video signal processing device.

[0008]

According to the video signal system discrimination method of the present invention,
Since the frequency of the clock pulse is known, the time of one vertical scanning period can be known from the number of clock pulses in one vertical scanning period, and the vertical scanning frequency can be known from this. Further, when the number of horizontal scanning lines in the two vertical scanning periods is the same, it can be determined as a non-interlaced signal, and when there is a difference in the number of horizontal scanning lines, it can be determined as an interlaced signal. Also, since the horizontal scanning frequency can be known from the number of horizontal scanning lines in this one vertical scanning period and the time in the one vertical scanning period, the number of clock pulses in the one vertical scanning period and the horizontal scanning lines in two vertical scanning periods are eventually measured. Each type of video signal system can be identified from the number.

Further, the video signal processing device according to the present invention stores the number of clock pulses in one vertical scanning period and the number of horizontal scanning lines in one or two vertical scanning periods according to the discrimination method for each video signal system to be discriminated. The video signal system corresponding to the data of the input video signal measured by the above-described determination method is determined from the stored memory, and the operation of the device is set.

[0010]

EXAMPLES Example 1. 1 and 2 are timing charts for explaining an embodiment of a video signal system discriminating method according to the invention of claim 1, and FIG. 1 (a) is a vertical synchronizing signal fV.
One vertical scanning period is counted by a clock pulse having a known frequency shown in FIG. 1B, and it is shown that the count value in one vertical period is VC.

FIG. 2 shows that the number of horizontal scanning lines (horizontal synchronizing signal fH) in two consecutive vertical scanning periods is counted, and the counted values are L1 and L2, respectively.

In this case, since the frequency of the clock pulse is known, (one vertical scanning period time) = VC / (clock pulse frequency), and the vertical scanning frequency is (vertical scanning frequency) = 1 / (one vertical scanning frequency). Scan period time) =
(Frequency of clock pulse) / VC, and the vertical scanning frequency can be expressed by the value of VC.

When L1 = L2, it is a non-interlaced signal (hereinafter referred to as "NI signal"), and L1 ≠ L.
If L1 -L2 = ± 1 in 2, the interlace signal (hereinafter,
"I signal").

Further, the horizontal scanning frequency is (horizontal scanning frequency) = L1 / (one vertical scanning period) in the case of an NI signal, and (horizontal scanning frequency) = (L1 + L2) / 2 (one vertical) in the case of an I signal. (Scanning period time), which can be represented by L1 and L1 + L2, respectively.

Therefore, the vertical scanning frequency, the horizontal scanning frequency, the number of horizontal scanning lines and the distinction between the NI signal and the I signal for specifying the video signal system are determined by the above-mentioned VC and L1,
It can be specified by the value of L2.

FIG. 3 shows a typical video signal system of NI and I, VC, L1 or L1 + L2 at a frequency of 1 MHz.
FIG. 4 is a diagram showing the values counted by the clock pulses of HW, HS + HB, HD, VS + VB and VD in the figure, respectively, which are the horizontal synchronizing signal fH and the vertical synchronizing signal f shown in FIG.
It is the size of each part of V and is the part required for printing.

Example 2. FIG. 5 is a block circuit diagram of an embodiment of the invention of claim 2. In the figure, 1 is a microcomputer (hereinafter referred to as “microcomputer”), and 2 is FIG.
ROM in which the processing program of the microcomputer 1 shown in FIG. 3 is written, 3 is RAM in which the parameter table shown in FIG. 3 is written, and 4 is horizontal in one vertical scanning period of the horizontal synchronizing signal input by the first counter. Count the number of scan lines. Reference numeral 5 is a second counter, 6 is a clock pulse generator for generating a clock pulse having a frequency of 1 MHz, and the second counter 5 counts the number of clock pulses in one vertical scanning period of the input vertical synchronizing signal. 7 is an A / D converter,
The input video signal is converted into digital data. 8
Reference numeral 9 is a data control circuit, 9 is a video memory, and 10 is a memory control circuit. Write in memory 9.
A color printer transfer circuit 11 is a key operation unit 1
Image data read from the video memory 9 is input via the data control circuit 8 under the control of the microcomputer 1 which receives a transfer command from the printer 2, and is printed on a sheet. A D / A converter 13 converts image data to be printed into an analog video signal and displays it on a monitor (not shown).

Next, the system discriminating operation of the input video signal by the microcomputer 1 will be described with reference to the flowcharts of FIGS. 5 and 6. When the microcomputer 1 receives a print command from the key operation unit 12, it first executes the first operation in S1 according to the program written in the ROM 2.
The counter 4 compares the count values L1 and L2 of the number of horizontal scanning lines in two consecutive vertical scanning periods to determine an NI signal or an I signal. When the signal is an NI signal, S2 sets L = L1 to set I = L1. When it is a signal, S3 sets L = L1 + L2 and S
Go to 4.

Next, in S4, a system having the same L value set in S2 or S3 and L in the parameter table (FIG. 3) of the RAM3 is searched. If not, the system having the closest L value is selected in S5, the process proceeds to S6, and the system searched in S4 or S5 having the same VC as the count value VC of the clock pulse in one vertical scanning period counted by the second counter 5. If there is a system with the same VC, proceed to S7 and determine that the system is the system of the input video signal. If there is no system with the same VC, proceed to S8 and find the closest value of VC. Search for a system that is
In step 8, it is determined that this searched system is an input video signal system.

Based on the parameters of the video signal system thus determined, the video signal input from the A / D converter 7 is automatically displayed in the video memory 9 according to the parameters of the video signal system. Data can be written.

Next, the microcomputer 1 operates the key operation unit 1
2 receives a printout command, the microcomputer 1 reads the data required for printing from the video memory 9 to the data control circuit 8 via the memory control 10, and the data control circuit 8 reads the data from the D / A converter circuit 1.
The image data is sent to 3 to display the image on the display, and the image data is sequentially sent to the color printer transfer circuit 11 to perform color printing.

According to the second embodiment, it is possible to automatically determine the system of the input video signal and write the image data in accordance with various parameters of the system in the video memory.

In the second embodiment, the video signal system discriminating method according to the invention of claim 1 is applied to the VCP, but it is also applied to the multi-scan display device and the device for recording the input video signal on the magneto-optical disk. can do.

[0024]

According to the first aspect of the present invention, one vertical scanning period of an input video signal is measured by a clock pulse, and the number of horizontal scanning lines in two consecutive vertical scanning periods is simply counted to obtain the input. The video signal system can be identified.

Further, according to the invention of claim 2, various video signals are preliminarily obtained by the above-mentioned discrimination method according to the count value of the number of clock pulses in one vertical scanning period and the number of horizontal scanning lines in two consecutive vertical scanning periods. Since various parameters of the input video signal system are read out from the memory that stores each parameter of the system, it is possible to obtain a video signal processing device that can automatically perform processing suitable for the system of the input video signal. To be

[Brief description of drawings]

FIG. 1 is a timing chart of a vertical synchronizing signal for explaining a first embodiment of a video signal system discriminating method according to the invention of claim 1.

FIG. 2 is a timing chart of a horizontal synchronizing signal for explaining the first embodiment of the video signal system discriminating method according to the invention of claim 1;

FIG. 3 shows L and VC of various video signal systems according to the first embodiment.
It is a figure which shows and each parameter.

FIG. 4 is a diagram showing configurations of a horizontal synchronizing signal and a vertical synchronizing signal of a video signal.

FIG. 5 is a block circuit diagram of a second embodiment of a video signal processing device according to the invention of claim 2;

FIG. 6 is a flowchart showing the processing in the microcomputer of the second embodiment.

[Explanation of symbols]

 1 Microcomputer 2 ROM 3 RAM 4 1st counter 5 2nd counter 6 Clock pulse generator 7 A / D converter 8 Data control circuit 9 Video memory 10 Memory control circuit 11 Color printer transfer circuit 12 Key operation unit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 5/76 E 7734-5C 5/91

Claims (2)

[Claims] 1. The number of clock pulses in one vertical scanning period of the input video signal and the number of horizontal scanning lines in two consecutive vertical scanning periods are respectively counted, and the input video signal is calculated from these data and the frequency of the clock pulse. A method for discriminating a video signal system, characterized by discriminating between a system interlace and a non-interlace, and a horizontal scanning frequency and a vertical scanning frequency. 2. A clock pulse generating means, a number of clock pulses when one vertical scanning period is counted with clock pulses having the same frequency as the clock pulse for each of a plurality of video signal systems, and one vertical pulse for a non-interlaced signal. A memory for preliminarily storing the number of horizontal scanning lines in the scanning period and the number of horizontal scanning lines in two consecutive vertical scanning periods for interlaced signals, means for counting the number of clock pulses in one vertical scanning period of the input video signal, A means for respectively counting the number of horizontal scanning lines in two consecutive vertical scanning periods, comparing the numbers of horizontal scanning lines in these two vertical scanning periods, and when the numbers are the same, a non-interlaced signal, the difference being one horizontal scanning line number. In this case, the means for discriminating the interlaced signal, the counted number of clock pulses in one vertical scanning period, and the input video signal are When the signal is a non-interlaced signal, the counted number of horizontal scanning lines in one vertical scanning period is compared. When the signal is an interlaced signal, the counted number of horizontal scanning lines in two vertical scanning periods is compared with the contents of the memory. And a video signal processing device having means for selecting the same or similar video signal system, and means for setting the operating condition of the video signal processing device so as to match the selected video signal system.