JPH04362885A - Static picture recording and regenerating device - Google Patents

Abstract

PURPOSE:To obtain a frame static image having no blurring and less deterioration of resolution when extracting part of a motion image to obtain a static image. CONSTITUTION:The static picture recording and regenerating is provided with a detecting means 25 for comparing picture elements for the first and second field images at nearly the same screen position to detect a moving area, and replacing means 26 and 27 for replacing picture element data corresponding to an area detected by the detecting means 25 out of those constituting the second field image with picture element data in an area nearly the same as that for the first field image. From the field image generated by the replacing means 26 and 27 and the first field image, a frame static image is obtained.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a still image recording and reproducing apparatus that obtains frame still images from a television signal in which two fields constitute one frame screen.

0002

2. Description of the Related Art As is well known, from a television signal such as the NTSC system where one frame of screen is composed of two fields, one frame worth of television signal is digitized and stored in a memory. By reading and playing one frame of image data,
There is a still image recording and reproducing device that obtains still images from moving images.

FIG. 3 shows such a conventional still image recording and reproducing apparatus. The television signal supplied to the input terminal 11 is sent to the A/D (analog/digital) conversion circuit 1
2, and two fields are stored in the memory 13. In this case, the memory 13 is controlled by an address generated by the address control circuit 15 based on the synchronization signal component of the television signal detected by the synchronization signal detection circuit 14.

Further, one frame of still image data stored in the memory 13 is read out based on an address generated by an address control circuit 15, and is converted into a still image by a D/A (digital/analog) conversion circuit 16. After being converted into a television signal for one picture and mixed with the synchronization signal component generated by the synchronization signal generation circuit 18 by the mixing circuit 17, the CR
An image is displayed at T (cathode ray tube) 19.

By the way, in the case of the NTSC system, an image for one field is obtained every 1/60 seconds, and one frame image is obtained by combining two temporally adjacent field images. A frame image will be obtained every 1/30 seconds. That is, there is a time difference of 1/60 second between the two field images that make up one frame image.

[0006] For this reason, one of the images with relatively fast movement
If a frame's worth of image data is simply stored in the memory 13 and reproduced as a still image, moving parts will appear blurred. For example, when photographing a person waving, the first field image and second field image are
As shown in FIGS. 4(a) and 4(b), the positions of the hands on the right side of the figures are different.

[0007] Therefore, when these two field images are combined and reproduced as one frame still image,
As shown in FIG. 4(c), a waving hand appears to be shaken, causing a problem that it is very disturbing. Note that if only one of the field images is reproduced as a still image instead of as a frame still image, the above problem does not occur, but there is an inconvenience that the resolution is reduced to 1/2.

[0008]

[Problems to be Solved by the Invention] As described above, conventional still image recording and reproducing devices that extract a part of a moving image to obtain a still image have the problem that moving parts appear blurred. .

[0009] Therefore, the present invention was made in consideration of the above circumstances, and when extracting a part of a moving image to obtain a still image, it is possible to obtain a frame still image without blur and with less deterioration in resolution. The object of the present invention is to provide an extremely good still image recording and reproducing device.

0010

[Means for Solving the Problems] A still image recording and reproducing apparatus according to the present invention is intended for obtaining a frame still image from an image signal in which a first field image and a second field image constitute one frame image. It is said that and detecting means for detecting a moving area by comparing pixel data of the first field image and the second field image at substantially the same screen position; replacement means for replacing pixel data corresponding to the area detected by the detection means with pixel data of substantially the same area of the first field image, and replacing the field image generated by the replacement means with the first field image. It is configured to obtain frame still images.

[0011]

[Operation] According to the above configuration, a moving area is detected by comparing the pixel data of the first field image and the second field image at substantially the same screen position, and the moving area is detected. Since the pixel data of the second field image corresponding to the second field image is replaced with the pixel data of the first field image, it is possible to obtain a frame still image without blur and with less deterioration in resolution.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. In FIG. 1, input terminal 20,
21 are supplied with first and second field image data, respectively. The first and second field image data supplied to these input terminals 20 and 21 are stored in the first field memory 23 and the second field memory 24, respectively, based on the address output from the address control circuit 22.

Here, the address control circuit 22 controls the first field memory 23 to read data so as to sequentially output data of each pixel of the first field image, and also controls the readout of the first field memory 23 so as to sequentially output the data of each pixel of the first field image. , readout control is performed so that data of each pixel of the second field image adjacent to each pixel of the first field image read out from the first field memory 23 is sequentially output.

[0014]The first and second field memories 2
Each pixel data read from 3 and 24 is sent to the comparator circuit 2.
5 and selector 26, respectively. This comparison circuit 25 calculates the difference component between each pixel data of the first and second fields, and outputs an H (high) level signal when the absolute value level of the difference value is greater than a preset reference value level. However, if it is less than the reference value level, an L (low) level signal is output.

The comparison output of this comparison circuit 25 is the selector 2
6. The selector 26 guides the pixel data output from the first field memory 23 to the second field sub-memory 27 when the comparison output is at the H level, and outputs it from the second field memory 24 when the comparison output is at the L level. It is switched so that the pixel data is led to the second field sub-memory 27.

The operation of the above configuration will be explained below. First, the first and second field memories 2
It is assumed that the first and second field images as shown in FIGS. 4(a) and 4(b) are stored in 3 and 24, respectively. Then, pixel data is sequentially read out from the first and second field memories 23 and 24 in the horizontal scanning direction from the upper left of the screen shown in FIGS.
is supplied to

For this reason, for example, in a facial part of the screen, the difference component between the respective pixel data obtained from the first and second field memories 23 and 24 is small, so the comparator circuit 2
5 becomes L level, and the selector 26 directs the pixel data output from the second field memory 24 as it is to the second field sub-memory 27, where it is stored under the control of the address control circuit 22.

On the other hand, since the right arm part of the first field screen shown in FIG. 4(a) is the background in the second field screen shown in FIG. 4(b), it is stored in the first and second field memories. The difference component between the respective pixel data obtained from 23 and 24 is large, the output of the comparison circuit 25 becomes H level, and the pixel data output from the first field memory 23 is stored in the second field sub-memory 27.

Furthermore, since the right arm part of the second field screen shown in FIG. 4(b) is the background in the first field screen shown in FIG. 4(a), the part of the arm on the right side of the second field screen shown in FIG. The difference component between the respective pixel data obtained from 23 and 24 is large, the output of the comparison circuit 25 becomes H level, and the pixel data output from the first field memory 23 is also stored in the second field sub-memory 27. become.

For this reason, the second field submemory 27
As shown in FIG. 2, image data approximately corresponding to the first field image is stored. A first field image taken out from the first field memory 23 via the output terminal 28, and a second field image which is a part of the first field image taken out from the second field sub-memory 27 via the output terminal 29. One frame image is constructed using

Therefore, according to the configuration of the above embodiment, the presence or absence of movement is determined based on the difference component between pixel data at substantially the same position in the first field image and the second field image, and the presence or absence of movement is determined. Since the pixel data of the second field image is replaced with the pixel data of the first field image in a certain portion, it is possible to obtain a frame still image without blur and with little deterioration in resolution. It should be noted that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without departing from the gist thereof.

[0022]

[Effects of the Invention] As detailed above, according to the present invention,
It is possible to provide an extremely good still image recording and reproducing device that can obtain a frame still image without blur and with little deterioration in resolution when extracting a part of a moving image to obtain a still image.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a still image recording and reproducing apparatus according to the present invention.

FIG. 2 is a diagram shown to explain the operation of the embodiment.

FIG. 3 is a block diagram showing a conventional still image recording and reproducing device.

FIG. 4 is a diagram shown to explain conventional problems.

[Explanation of symbols]

11...Input terminal, 12...A/D conversion circuit, 13...Memory, 14...Synchronization signal detection circuit, 15...Address control circuit,
16... D/A conversion circuit, 17... Mixing circuit, 18... Synchronization signal generation circuit, 19... CRT, 20, 21... Input terminal, 2
2... Address control circuit, 23... First field memory,
24... Second field memory, 25... Comparison circuit, 26...
Selector, 27...Second field sub-memory, 28,2
9...Output terminal.

Claims (1)

[Claims] 1. A still image recording and reproducing device that obtains a frame still image from an image signal in which a first field image and a second field image constitute one frame image, wherein the first field image and the second field image a detection means for detecting an area with movement by comparing pixel data at substantially the same screen position with the image; and a detection means corresponding to the area detected by the detection means among the pixel data constituting the second field image. replacing pixel data of the first field image with pixel data of substantially the same area of the first field image, and obtaining a frame still image from the field image generated by the replacing means and the first field image. A still image recording and reproducing device comprising: