JPH043599A - Picture evaluation device for video tape recorder - Google Patents

Abstract

PURPOSE:To attain picture evaluation simply without fail by providing a dropout evaluation circuit and a communication means to a host computer. CONSTITUTION:A vertical wide blanking pulse is obtained in the reproducing state of a VTR so as to distinguish whether a dropout takes place in the vertical wide blanking or in other parts. When information as to dropout occurrence location and the level (width) of the dropout and its number are inputted to a dropout evaluation circuit 13, the data are compared with an evaluation value preset by a microcomputer and evaluated and an error content or the like is displayed on a display section and the data is sent to a host computer 14 by the communication means. Thus, the occurrence location of the dropout is detected and the level and the number of dropouts are used to discriminate the propriety of the picture. Thus, the picture evaluation without fail is realized simply.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an image evaluation device for a video tape recorder used particularly in broadcasting stations and production stations.

Conventional technology In recent years, broadcasting stations and production companies have begun to use automation, but they currently rely on the human eye to evaluate the image quality of video tape recorders. It is shown in Figure 5. In FIG. 5, 1 indicates a playback system block of a video tape recorder (hereinafter referred to as VTR), including a video cylinder 2, heads a + b.
It has an S head amplifier 3, a dropout correction circuit 4, a signal processing circuit 5, a video output terminal 6, and a system control circuit 7. 8 is a monitor television receiver (hereinafter abbreviated as monitor TV) connected to the video output terminal 6;
9 is a dropout counter connected to the dropout correction circuit 4.

In the above configuration, the RF multiplied signals obtained from the heads a and b of the video cylinder 2 are amplified by the head amplifier 3.

At this time, the RF signal output sometimes has a low signal level, and this is usually called dropout. At this time, the RF multiplied signal is dropped, so in order to detect and correct this, the RF multiplied signal is passed through the dropout correction circuit 4 and converted into a video signal by the signal processing circuit 5.

However, this dropout correction circuit 4 generally uses the scanning lines before and after the horizontal scanning line to compensate for the missing portion, and for this reason, dropouts that span several H scanning lines (normally In the case of mass dropout (also called mass dropout), the corrected image covers a wide area, so the image quality is significantly degraded. I went there.

Problems to be Solved by the Invention With the above-mentioned conventional configuration, evaluation standards change as people change, and the images must be constantly monitored, which is a heavy workload for the person in charge and often leads to mass communication. I often missed the Dropout Gorge statue.

Furthermore, since the dropout counter 9 detects the width and number of dropouts detected by the dropout correction circuit 4 over the entire range of the RF multiplied signal output, for example, when a dropout of a delicate size (width) occurs, is again,
It took a lot of time to confirm and judge the location of the occurrence.

As described above, the evaluation of image deterioration due to dropouts is often left to judgment based on experience, which has been an obstacle to automation in broadcasting stations and broadcasting stations.

The present invention solves the above-mentioned problem. Image evaluation allows anyone to easily and accurately evaluate images by determining evaluation standards for VTR playback images based on data such as dropout detection positions and dropout sizes. The first objective is to provide an apparatus.

A second object of the present invention is to provide an image evaluation device that can distinguish between still images and moving images and set image evaluation criteria based on the type of tape material.

Means for Solving the Problems In order to solve the above problems, the image evaluation device of the present invention includes:
A system control circuit of a VTR, a dropout detection circuit, a dropout occurrence location detection circuit connected to the output of the system control circuit, an output of the dropout occurrence location detection circuit, and an output of the dropout detection circuit; A moving image detection circuit is provided to discriminate between a moving image and a still image of the video output reproduced by the tape recorder, and the output of this moving image detection circuit is input to the dropout evaluation circuit.

Effect: With the above-described configuration, it is possible to detect the location where dropouts occur and determine the quality of the image based on the size (width) and number of dropouts, so anyone can easily evaluate the image.

Furthermore, by distinguishing between moving images and still images, it is possible to set detailed image evaluation criteria, such as whether the material on the tape consists of many moving images or many still images. realizable.

Example An embodiment of the present invention will be described below based on the drawings.

FIG. 1 is a block diagram of an image evaluation device according to an embodiment of the present invention, and FIG. 2 is a waveform diagram of essential parts for explaining its operation. Things have the same parts or the same action.

In FIG. 1, IO is an image evaluation device, which includes a dropout occurrence point detection circuit 11, a moving image detection circuit 12, and a dropout evaluation circuit 13, and the dropout occurrence point detection circuit 11 includes a system control circuit 7 and A dropout detection section of the dropout correction circuit 4 is connected, a video output terminal 6 is connected to the video detection circuit 12, and a dropout occurrence point detection circuit 11 and a video detection circuit 12 are connected to the dropout evaluation circuit 13. The dropout detection section of the dropout correction circuit 4 is connected thereto.

The output section of the dropout evaluation circuit 13 is connected to the host computer 14, and the operation of the above configuration will be explained below. When the VTR is in the playback state, the outputs of heads a and b of the video cylinder 2 produce signals that are alternately output for each field, as shown in (b) and (cl) in FIG. By switching with a head switching signal as shown in Fig. 2 (al), a high frequency output signal as shown in Fig. 2 (dl) can be obtained. Figure 2 (diO high frequency output corresponds to the output of the head amplifier 3, and normally when a dropout occurs, this high frequency output signal is lost, so this dropout signal is passed through the dropout correction circuit 4. A configuration is adopted that detects out and corrects it.

Furthermore, regarding dropouts that occur over several H (horizontal lines are IH), the corrected signal err can be easily seen. However, in this state, monitor T
It was very noticeable in the center of the V8 image, but it was less noticeable in the periphery of the screen and in areas hidden by monitor TV8's overscan. This is due to the characteristics of the human eye; people tend to gaze at the center of the screen, but tend not to gaze at the periphery of the screen. Furthermore, when the image is a video, there is a tendency to focus attention on moving objects.

Therefore, in the reproduction state of the VTR, for example, a vertical wide blanking pulse as shown in FIG. The structure is such that it is possible to distinguish whether the occurrence occurred in a location other than the For example, the shaded area of the monitor TV image in Figure 2) belongs to a category other than vertical wide blanking, and this area is the area that is particularly watched. For parts outside of the parts, the evaluation criteria will be relaxed. Of course, the same level is fine. Normally, this shaded area is 40mm on the monitor screen.
It is desirable to set it to about % to 90%.

The dropout evaluation circuit 13 mainly includes a dropout counter section, a dropout width measurement section, a display section, an evaluation judgment section using a microcomputer, a communication section with the host computer 14, etc. .

When information about the location of dropouts, the size (width) and number of dropouts are input to the dropout evaluation circuit 13, they are compared with preset evaluation values in the microcomputer, evaluated, and displayed on the display. At the same time, the data is sent to the host computer 14 via communication means.

The host computer 14 prints out this data or displays an error on the screen to notify the operator of the image evaluation results. Furthermore, since the image evaluation device 11 also has a display section, the content of the error occurrence can be easily understood without looking at the screen of the host combinator 14. When this error occurs, it can be notified to the operator more effectively by linking with a sounding unit such as a buzzer.

In the above description, the dropout occurrence point is detected using only the vertical wide blanking width, but as shown in FIG. 3, the image judgment can also be performed by adding horizontal wide blanking as well. In FIG. 3, lal represents a high frequency output signal, (bl represents a horizontal wide blanking pulse, and BL represents a monitor TV image with vertical and horizontal wide blanking).

In this case, there is an effect that the evaluation criteria based on the vertical blanking described above can be determined in more detail.

The specific image evaluation method needs to be reset as the level changes depending on the broadcasting station and production period, but in Tsu Jigiri, setting the - degree has the effect that anyone can easily and accurately evaluate the image from now on. .

Next, the moving image detection circuit 12 that further improves image evaluation will be explained. A specific example of the moving image detection circuit 12 is shown in functional blocks in FIG. In Figure 4, 1
5 is an analog/digital (A10) conversion circuit, 16
and 17, a frame memory and one frame delay circuit connected to the NΦ conversion circuit 15; and 18, a frame memory 19 connected to the one frame delay circuit 17, a comparison judgment circuit connected to the frame memories 16 and 18.

Normally, the frame memories 16, 18, 1, frame delay circuit 17, comparison and determination circuit 19, etc. are controlled by a microcomputer for determination.

The operation will be explained below. When a video signal is input, the A/D conversion circuit 15 converts it into a digital signal. This converted signal is the frame memory 1
6, and the other is input to the frame memory 18 via the one frame delay circuit 17. By comparing and determining these two systems of signals in the comparison and determination circuit 19, it can be determined that if they match, it is a still image, and if they do not match, it is determined that it is a moving image.

After determining whether it is a moving image or a still image in this way, the type of material on the tape (such as whether it is a material with many moving images or a material with many still images) is determined by inputting it to the dropout evaluation circuit 13.
Since image evaluation criteria can be set in detail, anyone can easily and accurately obtain image evaluations.

Effects of the Invention As described above, according to the present invention, anyone can easily and accurately evaluate VTR images using the dropout occurrence point detection circuit, the size and number of dropouts, etc., and this effect is great. There is something.

Furthermore, by providing a moving image detection circuit, it is possible to determine whether a moving image or a still image is present, which allows detailed setting of image evaluation criteria depending on the type of tape material, and furthermore, enables easy and reliable image evaluation.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a VTR image evaluation device according to an embodiment of the present invention, and FIG. 2 is a main part waveform diagram and a front view of a monitor TV screen for explaining the operation of the image evaluation device.
FIG. 3 is a waveform diagram of essential parts and a front view of a monitor TV screen for explaining further operations of the image evaluation device, FIG. 4 is a block diagram showing an example of a moving image detection circuit of the image evaluation device, and FIG. The figure is a block diagram of a conventional image evaluation device. 1...VTR playback system, 2...video cylinder, 4
. . . Dropout correction circuit, 5. Signal processing circuit, 7. System control circuit, 10. Image evaluation device, 11. Dropout occurrence point detection circuit, 12. Video detection circuit. , 13... Dropout evaluation circuit, 14... Host computer, 15...
Analog/digital conversion circuit, 16.18... Claim memory, 17... l frame delay circuit, 19...
・Comparison judgment circuit.

Claims (1)

[Scope of Claims] 1. A system control circuit for a video tape recorder, a dropout detection circuit for detecting a dropout in a playback signal of the video tape recorder, and a dropout occurrence point detection circuit connected to the system control circuit. An image evaluation device for a video tape recorder, comprising: a dropout evaluation circuit connected to the dropout occurrence point detection circuit and the dropout detection circuit, respectively; and communication means to a host computer. 2. The apparatus according to claim 1, further comprising a moving image detection circuit for discriminating between a moving image and a still image of a video output reproduced by a video tape recorder, and the moving image detecting circuit is connected to an input section of a dropout evaluation circuit. video tape recorder image evaluation device.