JPH03179889A - Frame/field automatic changeover device in still picture - Google Patents

Abstract

PURPOSE:To improve the transmission efficiency by detecting a blur from a pattern of a frame display, selecting one field display and displaying a still picture without blur. CONSTITUTION:A movement detector 13 is provided, which applies threshold value processing to a difference of a required picture element data of two field memories 11, 12 storing respectively each picture element data in a video signal of a 1st field and each picture element data in a video signal of a 2nd field among digital video signals and detects the presence of a blur of a picture. Moreover, When the movement detector 13 receiving the picture element data of both the field memories 11, 12 detects the absence of a blur, the video signal being the result of synthesizing the picture data of both the field memories is outputted and when any blur is detected, either of them is selected and the video signal synthesized in a way of displaying the line of the picture element data twice is outputted by a selector. Thus, a still picture without blur is offered to a viewer at any time and the transmission efficiency is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an automatic frame/field switching device for still images, and in particular, to an apparatus for automatically switching frames/fields for still images, and in particular, for automatically switching still images from video display to still image display from frame display to single field display. Regarding things that can be switched to.

[Conventional technology]

FIG. 2 is a block diagram of a conventional moving image/still image display switching device. 1 is an A/D converter that converts an analog video signal into a digital video signal, 2 is a frame memory that stores the digital video signal, and 3 is a frame memory 2 that stores the video signal output from the A/D converter 1. a first changeover switch for switching whether or not to allow input; 4;
is a second changeover switch that switches between outputting the video signal converted by the A/D converter 1 and outputting the video signal stored in the frame memory 2. The signal input to this A/D converter 1 is an analog video signal, and the first field and second field are interlaced.
It consists of field video signals, and one screen is composed of these two video signals.

To display a video, move the first switch 3 to the 3a side.
Turn the second changeover switch to the 4a side. Then, A/D
The digital video signal output from the converter 1 is output as is through the line 5, and becomes a moving image output.By passing through a D/A converter (not shown), it becomes an analog video signal and displays a moving image. can be done.

Also, when displaying a still image, set the first selector switch 3 to 3.
Turn it to the b side. Then, the digital video signal output from the A/D converter 1 is stored in the frame memory 2. This stored video signal is one screen of a moving image at a certain moment. Frame memory 21: After the video signal for one screen is stored, the first changeover switch 3 is disconnected from 3b, and the second changeover switch 4 is turned to the side 4b, so that one screen stored in the frame memory 2 is A digital video signal corresponding to the number of minutes is outputted, becomes a still image output, and is converted into an analog video signal by passing through a D/A converter (not shown), so that a still image can be displayed. Displaying such still images can be done by operating the first switch 3 and second switch 4 at a certain time to switch from video display to still image display, or by operating both switches 3.4 at regular time intervals. This was done by switching from video display to still image display. Such image display switching is performed on the transmitting side where a moving image/still image display switching device is provided.

[Problems to be Solved by the Invention] However, in the video/still image switching device with the above configuration,
The video signals of the first field and the second field converted into digital data by the A/D converter 1 are stored in the frame memory 2, and these are taken out from the frame memory 2 and output as a still image output. When displaying a still image by freezing the image, the still image would sometimes blur when there was a lot of movement in the moving image, making it difficult to see visually. This is because the analog video signal manually input to the A/D converter 1 is based on the interlace system, so the signal that makes up one screen is obtained by scanning the first field and then scanning the second field. Since it takes 1780 seconds to scan one field, it takes 1780 seconds to scan both fields. Therefore, if you pay attention to an arbitrary line in the first field, there will be a delay of 1/60 seconds in the lines in the second field that are close to that line. This is because the still image after 1/80 seconds is displayed twice, that is, blurring occurs (such a display that combines the video signals of the first field and the second field is hereinafter referred to as "frame display"). 1゜In order to eliminate the problem of displaying a blurred still image as described above, the present invention detects blur from a frame display screen, switches to single field display, and displays a still image without blur. An object of the present invention is to provide an excellent automatic frame/field switching device for still images that can improve transmission efficiency.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a frame/field automatic switching device for still images that stores each pixel data of a first field video signal of a digital video signal. a first field memory; a second field memory storing each pixel data of a second field of the video signal; and predetermined pixel data of the first field memory and predetermined pixel data of the second field memory. A motion detector detects the presence or absence of blur in the image by thresholding the difference value of When the motion detector detects the motion, it outputs a video signal that combines the image data of both field memories, and when the motion detector detects that there is a blur, the first
A selector is provided for selecting either the field or the second field of image data and outputting a video signal synthesized so that the line of pixel data is displayed twice.

[Function] According to the present invention, since the frame/field automatic switching device for still images is configured as described above, each pixel data of the video signal of the first field of the video signal converted from analog to digital is is stored in the first field memory, each pixel data of the video signal of the second field is stored in the second field memory, and each pixel data of the video signal stored in both field memories is sent to the selector. Further, the motion detector performs threshold processing on the difference value between predetermined pixel data stored in the first field memory and predetermined pixel data stored in the second field memory to detect the presence or absence of blur in the image. . When the selector receives a detection signal from the motion detector indicating that there is no blurring, it outputs a digital video signal that is a composite of the pixel data stored in the first and second field memories, and detects that there is no blurring from the motion detector. When it receives a detection signal, it selects either the pixel data in the first field memory or the second field memory, outputs a digital video signal that is synthesized so that the line of pixel data is displayed twice, and It is possible to provide still images without blur even when Therefore, the above problem can be eliminated.

[Embodiment Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 3 (
FIGS. 3A and 3B are explanatory diagrams showing the concept of a motion detector detecting blur in an image. In the figure, 11 is a first field memory that stores each pixel data of the first field video signal of the digital video signal, and 12 stores each pixel data of the second field video signal of the digital video signal. A second field memory 13 is an operation that performs threshold processing on the difference value between the pixel data stored in the first field memory 11 and the pixel data stored in the second field memory 12 to detect the presence or absence of image blur. The detector 14 manually detects the pixel data stored in the first field memory 11 and the pixel data stored in the second field memory 12, and detects both fields based on the detection signal of the presence or absence of blur from the motion detector i3. A selector that switches between outputting a digital video signal that combines the pixel data of the memory, or outputting a digital video signal that combines the pixel data of either field memory so that the line of pixel data is displayed twice. be.

Next, the operation of the above embodiment will be explained.

First field memory 11 and second field memory 12
A video signal converted from analog to digital by A/D conversion is input manually. The first field memory 11 stores each pixel data of the first field of the digital video signal, and the second field memory 12 stores the second field of the digital video signal.
Each pixel data of the field video signal is stored.

Each pixel data of the video signal stored in these field memories 11 and 12 is sent to the selector 14. Also,
The motion detector 13 receives 16 out of the pixel data stored in the first field memory 11 as shown in FIG. 3(a).
As shown in FIG. 3(b), among the pixel data of an arbitrarily selected region R consisting of 16 pixels e and the pixel data stored in the second field memory 12, the first Pixel data of a region S at a position corresponding to the region R selected in the field memory 11 is input. Then, the motion detector 13 calculates the difference value between the pixel values of the pixel data of these regions R and S, and performs threshold processing on the difference value to detect the presence or absence of blur in the image. That is, the area R
If the pixel values of the pixel data of the area S and the pixel values of the pixel data of the area S are approximately equal, it can be determined that there is no blur in the image in that area. When the value exceeds , it can be determined that the image is blurred. Therefore, it is possible to detect the presence or absence of blur. The reason for selecting the pixel values of the number of pixels in the predetermined regions R and S in this manner is that it would take too much time to select the pixel values for the number of pixels in the entire region. Note that it goes without saying that the number of areas can be increased and the positions and sizes can be changed.

The signal from the motion detector 13 that detects the presence or absence of blur in the image is input to the selector 14, and when the selector 14 receives a detection signal indicating that there is no blur from the motion detector 13, the first
The pixel data stored in the field memory 11 and the second field memory I2 are combined to display one screen (
Outputs a digital video signal that can be displayed (frame display). If this video signal is D/A converted, it will be converted into an analog signal and a still image can be obtained by displaying a frame. Further, when the selector 14 receives a detection signal from the motion detector 13 indicating that there is a shake, it selects either the pixel data of the first field memory 11 or the second field memory 12, and selects the pixel data of the selected, for example, the first field. A digital video signal that can be displayed on one screen (single field display) is output by combining the lines of pixel data in the memory so that they are displayed twice. This video signal is
/A conversion converts the signal into an analog signal and provides a still image with single-field display. Note that when outputting a digital video signal that displays frames, the subsequent encoding for transmission must process all lines of one screen; however, when outputting a digital video signal that displays one field, For example, if only the pixel data of the first field is encoded, the pixel data of the second field is the same pixel data as the line of the first field directly above. Since the pixel data of the second field does not need to be displayed, and only half of the lines need to be targeted, the time required for encoding is approximately halved, and the transmission time is also approximately It is also more economical than encoding and transmitting frame representations.

[Effects of the Invention] As described in detail above, according to the present invention, the data of each pixel of the first field video signal out of the digital video signal stored in the first field memory and the data stored in the second field memory The motion detector sends the data of each pixel of the video signal of the second field among the video signals stored in the first field memory to the selector. The presence or absence of image blur is detected by thresholding the difference value between the second field video signal stored in the second field memory and the predetermined pixel data, and the selector detects the presence or absence of image blur from the motion detector. When the detection signal is received, the first
and outputs a digital video signal obtained by synthesizing the pixel data stored in the second field memory, and when a detection signal indicating that there is a blur is received from the motion detector, the pixel data in the first field memory or the second field memory is output. The system outputs a composite digital video signal that displays the line of pixel data twice, allowing the receiver to receive a still image without blur at any time. Furthermore, if the motion detector detects that there is a blur, it outputs a video signal that is synthesized so that the line of pixel data of one field memory selected by the selector is displayed twice.
Only one field needs to be encoded for transmission, and the time required for encoding is reduced by about half, which reduces transmission time by about half, making it economical and improving transmission efficiency. You can also expect

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram of a conventional video/still image display switching device, and FIGS. It is an explanatory diagram showing a concept of detecting. l(...first field memory, 12...second field memory, 13...motion detector, 14...selector.

Claims (1)

[Scope of Claims] A first field memory that stores each pixel data of a first field video signal of a video signal converted from analog to digital; and each pixel of a second field video signal of the video signal. A second field memory stores data, and threshold processing is performed on the difference value between predetermined pixel data stored in the first field memory and predetermined pixel data stored in the second field memory to eliminate image blur. a motion detector that detects the presence or absence of each pixel;
Each pixel data stored in the field memory is input, and when the motion detector detects that there is no blur, it outputs a digital video signal that combines the image data of both field memories based on that signal, and the motion detector When it detects that there is a blur, it selects either the pixel data in the first field memory or the second field memory based on that signal, and synthesizes the digital video signal so that the line of that pixel data is displayed twice. 1. An automatic frame/field switching device for still images, comprising: a selector for outputting a frame/field switching device for still images;