JPH05284453A - Digital data recording and reproduction device - Google Patents

Abstract

PURPOSE:To correct an error effectively even when no correlation is in existence in data between a field with a code error caused therein and its preceding field in the digital data recording and reproducing device. CONSTITUTION:A correction section 5' provided to an output of an error correction section 4 consists of the combination of a memory 7 and a deduction section 8 and data of a picture element not corrected by the error correction section 4 are estimated by using digital data around its picture element and the data are replaced with the estimated data as the correction. Thus, even when no correlation is in existence in data between a field with a code error caused therein and its preceding field, the error is corrected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital data recording / reproducing apparatus for digitizing and recording / reproducing a video signal, such as a digital video tape recorder (hereinafter referred to as "digital VTR"). The present invention relates to a digital data recording / reproducing apparatus capable of effectively performing error correction even when there is no correlation between data in a field and a previous field.

[0002]

2. Description of the Related Art In recent years, with the progress of digital ICs (integrated circuits), a digital VTR for digitizing a video signal of a television to enable high image quality recording / reproduction has been developed. And such a digital VTR is
As shown in FIG. 4, A /
A D converter 1, an error correction code section 2 for adding an error correction code for correcting a code error at the time of recording to the digital data from the A / D converter 1, and an error correction code section 2 A recording / reproducing unit 3 for recording and reproducing the digital data to which the error correction code is added in the magnetic recording medium.
And an error correction unit 4 for correcting the code error of the digital data read from the recording / reproducing unit 3 using the added error correction code, and the error data that cannot be corrected by the error correction unit 4 to other pixels. It has a retouching section 5 for substituting the data of No. 2 for remedying an error and a D / A converter 6 for converting the digital data from the retouching section 5 into a video signal.

The correction of the data error in the correction unit 5 mainly corrects the error that cannot be corrected by the error correction unit 4, but the following method is used. The first is a method that uses the data at the same position in the field immediately preceding the field in which there is an error in the data and replaces it with error data to correct it. Second,
In the same manner as described above, for example, the data at the same position four fields before is used to replace the error data for correction. Third, using the data of the line adjacent to the error data in the same field with the data error,
It is a method of replacing and modifying.

[0004]

However, in the correction of the data error in such a conventional digital VTR, in any of the first to third correction methods, the field in which the data is erroneous and the field before it are corrected. It was corrected by replacing the data assuming that there is a correlation with the fields, but if there was no correlation between the two fields, good error correction could not be achieved. For example, in the case of a television broadcast image, when the image content of the field is significantly different from that of the previous field, such as when changing from one scene to another, the correction unit 5 in FIG. When the data at the same position in a field before a certain field is used to replace the error data, the error portion becomes conspicuous. Therefore, it was not possible to modify the data for all the error occurrences.

Therefore, the present invention addresses such a problem, and can effectively perform error correction even when there is no correlation between data in a field in which a code error has occurred and a field before the code error. An object is to provide a data recording / reproducing device.

[0006]

In order to achieve the above object, a digital data recording / reproducing apparatus according to the present invention comprises an A / D converter for digitizing a video signal and the A / D converter.
An error correction code unit for adding an error correction code for correcting a code error at the time of recording to the digital data from the D converter and a digital data to which the error correction code is added by this error correction code unit is magnetically recorded. A recording / reproducing unit for recording / reproducing on / from a recording medium, an error correcting unit for correcting a code error of digital data read from the recording / reproducing unit using the above-mentioned added error correction code, and this error correcting unit cannot correct the error. In the digital data recording / reproducing apparatus, the digital data recording / reproducing apparatus has a correction unit for replacing the error data with the data of another pixel to correct the error, and a D / A converter for converting the digital data from the correction unit into a video signal. Section estimates the data value of the pixel data that could not be corrected by the error correction section, using the digital data around the pixel. Is obtained shall retouching by replacing the data values.

[0007]

In the digital data recording / reproducing apparatus having the above-described structure, the data value is estimated by using the digital data around the pixel having the code error, and the data of the pixel is replaced by this data value to record the data by the modifying unit. It operates to correct the pixel data that could not be corrected by the error correction unit provided on the read side of the reproduction unit. As a result, even if there is no correlation between the data in the field in which the code error has occurred and the previous field, error correction can be effectively performed regardless of the previous field.

[0008]

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a digital data recording / reproducing apparatus according to the present invention. This digital data recording / reproducing apparatus digitizes a video signal input from an external image device or the like and records or reproduces it, and also converts the read digital data into a video signal and outputs the video signal. The error correction code section 2, the recording / reproducing section 3, the error correcting section 4, the modifying section 5 ', and the D / A converter 6 are provided.

The A / D converter 1 digitizes a video signal input from a medical image device (not shown) or the like and outputs image data. The error correction code unit 2 adds an error correction code for correcting a code error during recording to the digital data output from the A / D converter 1 during reproduction. The recording / reproducing unit 3 inputs the digital data to which the error correction code is added by the error correction encoding unit 2 and records and reproduces it on a magnetic recording medium such as a magnetic tape. It has a built-in recording / playback head. The error correction unit 4 corrects the code error of the digital data read from the recording / reproducing unit 3 using the error correction code added by the error correction code unit 2.

Then, the correction unit 5'includes the error correction unit 4 described above.
The error data that could not be corrected in step 1 is replaced with the data of another pixel to correct the error. Furthermore, D / A
The converter 6 converts the digital data output from the modifying unit 5'into a video signal and sends it to a medical image device (not shown) or the like.

Here, in the present invention, the retouching section 5'estimates the data value of the pixel data which could not be corrected by the error correction section 4 by using the digital data around the pixel, and estimates this data value. It is modified by replacing it with a value, and is composed of a combination of the memory 7 and the inference unit 8. The memory 7 takes in the digital data after the error correction of the data by the error correction unit 4 and stores it as it is. Further, the inference unit 8 inputs the error signal S to that effect for error data that cannot be corrected by the error correction unit 4 and estimates and determines a data value to be replaced with the error data. The estimation of this data value is performed using digital data around the pixel in which the error has occurred.

Next, the estimation of the data value to be replaced with the error data in the inference unit 8 will be described with reference to FIG. FIG. 2 shows image data of a size of 5 × 5 pixels, and letters a, b, c, ... Show addresses of each pixel. Now, as indicated by hatching in the central portion, it is assumed that the pixel data at the address a is error data that cannot be corrected by the error correction unit 4. In this example, the data value of the pixel a is estimated using the data of 24 pixels b to y existing around the pixel a in which the error has occurred. An example of the inference algorithm is as follows. (1) When the variation in the pixel data around the pixel a is small, the average value of the pixel data in the peripheral region of the pixel a (for example, the modification area 9 of 5 × 5 pixels) is used as the data value of the pixel a. Yes (Rule 1). (2) When pixels having the same or extremely similar data values exist before and after the pixel a, the data value of the same or extremely similar pixels is set as the data value of the pixel a (rule 2). (3) When the pixel data around the pixel a varies, the data value of the pixel adjacent to the pixel a is set as the data value of the pixel a (rule 3). As mentioned above, there are three inference algorithms,
In the actual estimation of the data value, some of the above three rules are combined to estimate and determine the data value of the target error pixel. Then, the determined data value is sent to the memory 7 and replaced with the data of the error pixel to correct the error. As a result, the data of the pixel a in which the error has occurred can be modified to make the error inconspicuous.

Although FIG. 2 shows an example in which a correction area 9 of 5 × 5 pixels for data correction is set with the pixel a in which an error has occurred in the center, as shown in FIG. When the pixel a in which an error has occurred is in the peripheral portion of the image 10, it is only necessary to set a retouching area 9 of 5 × 5 pixels in which the pixel a is the center of one side and the other side spreads out.
2 and 3, an example in which a region of 5 × 5 pixels is set as the modification area 9 is shown, but the present invention is not limited to this, and 3 × 3 pixels or 6 × 6 pixels or that Areas of other sizes may be used, and may be appropriately determined according to the processing speed.

If an error occurs in a continuous moving image, it may be better to replace the data in the field preceding the field in which the data is erroneous as in the conventional example. Determine whether there is a correlation between the generated field data and the previous field data,
If there is a correlation between the two, an algorithm of "replace with the data of the previous field" may be added as rule 4 to the above three rules. In this case, the modifying unit 5'performs the same operation as the modifying unit 5 in the conventional example shown in FIG.

Further, as shown in FIG. 1, digital data is directly input to the error correction code unit 2 from a medical image device (not shown) or the like, and the correction unit 5'applies to the medical image device or the like. You may make it transmit digital data directly.

[0016]

Since the present invention is constructed as described above,
An error correction provided on the reading side of the recording / reproducing section 3 is performed by estimating the data value of digital data around a pixel having a code error by the correction section 5'and replacing the data of the pixel with this data value. It is possible to modify the pixel data that could not be corrected by the unit 4. As a result, even if there is no correlation between the data in the field in which the code error has occurred and the previous field, error correction can be effectively performed regardless of the previous field. Therefore, it is possible to correct the data for all the error occurrences and make the displayed image easy to see.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a digital data recording / reproducing apparatus according to the present invention,

FIG. 2 is an explanatory diagram showing a state in which a data value to be replaced with error data is estimated in the inference unit,

FIG. 3 is an explanatory diagram showing another example of the retouching area when the data value to be replaced with the error data is estimated by the inference unit.

FIG. 4 is a block diagram showing a conventional digital data recording / reproducing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... A / D converter, 2 ... Error correction code part, 3 ... Recording / reproducing part, 4 ... Error correction part, 5 '... Correction part, 6 ... D
/ A converter, 7 ... memory, 8 ... inference section, 9 ... retouching area.

Claims (1)

[Claims] 1. An A / D converter for digitizing a video signal, and an error correction for adding an error correction code for correcting a code error during recording to a digital data from the A / D converter during reproduction. A code section, a recording / reproducing section for recording and reproducing the digital data to which the error correction code is added by the error correcting code section on the magnetic recording medium, and a code error of the digital data read from the recording / reproducing section are added to the above. An error correction unit that corrects using an error correction code,
Digital having a correction section for replacing error data that could not be corrected by the error correction section with data of another pixel to correct an error, and a D / A converter for converting digital data from the correction section into a video signal. In the data recording / reproducing apparatus, the modifying unit modifies the data of the pixel that cannot be corrected by the error correcting unit by estimating its data value using digital data around the pixel and replacing it with this data value. A digital data recording / reproducing apparatus characterized in that