JPH0612477A - Picture recorder - Google Patents

Abstract

PURPOSE:To suppress the block distortion of a picture for retrieval by eliminating the occurrence of the block distortion even at the time of reading out recorded picture data. CONSTITUTION:An original picture is pressed through a spatial filter circuit 110 to generate a small picture by reducing it by a 1/n circuit 112 so as to obtain an integer-fold picture of a DCT(discrete cosine transform) block unit, and it is written to a frame memory 114 by a write/read circuit 122 so that the boundary between reduced screens does not straddle over the DCT block. By subjecting the picture to DCT in a DCT circuit 116, the boundary of small screens of the picture for retrieval can be so set that it does not straddle over the DCT block. Therefore, the picture for retrieval which is less degraded by the block distortion and has an excellent picture quality is obtained. Since small screens for retrieval are generated from the original picture, it is unnecessary to generate and input the picture for retrieval again, and the manpower is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image recording device for recording image data. The present invention relates to an image recording apparatus that records image data, creates search image data of the recorded image data, and records the image data.

[0002]

2. Description of the Related Art In recent years, due to the increase in the capacity of recording media such as disks and tapes, the development of high-density recording technology, and the high-efficiency encoding of images, there is a large amount of information such as the high-vision standard. Also, a large amount of still image data can be recorded on a medium such as a disk. In order to retrieve this large amount of recorded image data, the original screen as shown in FIG. 2 is changed to d ₁₁ , d ₁₂ , d ₁₃ , ..., D _nn as shown in FIG.
The small screen is divided and arranged, and the small screen is recorded as the small screen for search and the image for search.

An example of a conventional recording apparatus for such a small screen is shown in FIG.
Shown in. In FIG. 5, 100 is an input terminal for digital image data, 102 is an input buffer, 104 is a discrete cosine transform (DCT) circuit, and 106 is variable length coding (VL).
C) circuit, 108 is a non-indexable circuit for retrieval, 12
4 is a CPU, 126 is a disk drive, 128 is a disk which is a recording medium, and A is an address, data and control bus.

The conventional small image recording control having the above-mentioned structure will be described below with reference to FIG. First, the digital data of the still image D ₁₁ which is the original image is input terminal 1
00, the DCT circuit 104 performs DCT via the buffer 102 for each m × m (for example, m = 8) block, and transforms the spatial domain into the frequency domain. The converted image data is sent to the VLC circuit 106, variable length coded and compressed.

The image data that has been variable-length coded and compressed is sent to the search index unusable circuit 108, and the search index information is added thereto. Then, it is sent to the disk drive 126 via the bus A, and the disk 128
Recorded in. This series of processing is performed under the control of the CPU 124. Similarly, the original image, a still image,
D ₁₂ , D ₁₃ , ..., D _nn are sequentially recorded on the disk 128.

Further, the original image D _ij (i = 1) shown in FIG.
.About.n, j = 1 to n), the small screens _dij are arranged as shown in FIG.
To do. After that, the VLC circuit 106 performs variable length coding. Then, the index for search is added in the index-for-search circuit 108. After that, it is sent to the disk drive 126 via the bus A and recorded on the disk 128 as a search image. When adding a still image to be recorded, the above process is repeated, and the search images are added to 1, 2, ...,
Increase as l.

At the time of reproduction, the user can know the type of the image recorded on the disk and can retrieve it by reproducing the image for retrieval.

[0008]

However, in the above-mentioned conventional example, in the search image, the small screens d ₁₁ and d ₁₂ are processed as completely different pictures (images) as shown in FIG. For this reason, if the DCT block straddles the boundary between both small screens, block distortion is likely to appear at the time of reproduction and it is inevitable that the image quality is deteriorated.

[0009]

The present invention has been made for the purpose of solving the above-mentioned problems, and has the following structure as one means for solving the above-mentioned problems. That is, a frame memory that records image data, and a reduction unit that reduces the input image data to be an integral multiple of a processing unit block,
Recording control means for controlling the write start address of the reduced image data in the reduction means to be an integral multiple of the processing unit block and writing it in the frame memory.

[0010]

With the above arrangement, block distortion does not occur even when the recorded image data is read out, and the block distortion of the search image can be suppressed.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described in detail below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention. The configuration of this embodiment will be described below with reference to FIG. 1, the same components as those in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

In FIG. 1, 100 is a still image D which is the original image.
_ij data input terminal 104 is a discrete cosine transform (D
CT) circuit, 106 is a variable length coding (VLC) circuit, 1
Reference numeral 08 is a search index adding circuit, 110 is a spatial filter circuit, and 112 is the original image D _ij reduced to 1 / n 1
/ N circuit, 114 is a frame memory (FM), 116 is a discrete cosine transform (DCT) circuit, 118 is a variable length coding (VLC) circuit, 120 is a search index addition circuit, and 122 is a frame memory write / read control. Circuit, 124 is CPU, 126 is disk drive, 1
Reference numeral 28 is a disk (for example, a magneto-optical disk) which is a recording medium. A is a data, address and control bus.

In the present embodiment having the above configuration, the original image D _ij input from the input terminal 100 is passed through the buffer 102 to the DCT circuit 104 and the spatial filter circuit 1.
Sent to 10. The processing from the DCT circuit 104 is the same as that of the conventional example, and therefore its description is omitted. Space filter circuit 110
Then, the filtering process is performed on the original image D _ij . Then, subsequently, in the 1 / n circuit 112, the original image D _ij is reduced to 1 / n in the vertical and horizontal directions (n = 1, 2, 3, ...). However, in this embodiment, the CPU 124 sets n as
A value that is an integral multiple of the block unit m × m of DCT when the original image D _ij is reduced to 1 / n is set.

That is, the CPU 124 sets n so that W × (1 / n) = km (k = 1, 2, 3, ...) When W is the number of effective pixels in the horizontal direction. . Here, the CPU 124 has already
The coefficients and tap numbers of the spatial filter circuit 110 are set so that there is no aliasing distortion of the spatial frequency even if the original image D _ij is reduced to 1 / n, and filtering is performed. Then, the 1 / n circuit 112 _{converts the} original image D _ij into 1 / n
To a small screen _dij , and the frame memory (F
M) Write the small screen _dij to 114.

The writing / reading control circuit 122, when writing the small screen _dij to the frame memory 114, sets the CP
Under the control of U124, the write start address is set to {(i-1) km, (j-1) k in the horizontal and vertical directions, respectively.
m} (i, j = 1, 2, ..., N). As described above, the still images D ₁₁ , D ₁₂ , D ₁₃ , which are the original images,
..., D _nn are written in the frame memory 114.

The write / read control circuit 122 writes the image data in the frame memory 114 in this manner, and then reads the written data under the control of the CPU 124. The read data is sent to the DCT circuit 116 in exactly the same order as when the data is sent from the buffer 102 to the DCT circuit 104. The DCT circuit 116 DCTs the small screen data sent from the frame memory 114 and sends it to the VLC circuit 118. V
The LC circuit 118 performs variable-length coding on the DCT-converted data, compresses it, and sends it to the search index adding circuit 120. The search index adding circuit 120 adds the search index as a header, sends the data to the bus A, and sends the data to the disk 12 via the disk drive 126.
8 is recorded as search image data.

As described above, according to this embodiment, the original
Image D_ijThrough the space filter, DCT block unit
It is reduced to be an integer multiple of, and the boundary between reduced screens is D
To the frame memory so that it does not straddle the CT block
Write control to write to frame memory, or
By performing DCT from the
Borders can be set so that they do not span DCT blocks
Therefore, search with excellent image quality with little deterioration due to block distortion
It is possible to obtain an image for use. Also, the original image D _ijFrom
Small screen for searching d_ijI will create a new image for search
There is no need to enter and input, which also saves labor.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of a single device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0019]

As described above, according to the present invention, it is possible to obtain a high-quality search image with little block distortion. Further, since the search image is created from the input image, it is not necessary to newly create and input the search image, which saves labor.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment according to the present invention.

FIG. 2 is a diagram showing an original input image.

FIG. 3 is a diagram showing an example in which the original screen shown in FIG. 2 is divided into small screens and arranged.

FIG. 4 is a diagram illustrating a state in which a block distortion is likely to appear during reproduction when a DCT block straddles the boundary of a divided small screen.

FIG. 5 is a block diagram showing a conventional small screen recording apparatus.

[Explanation of symbols]

 102 buffer circuit 104, 116 DCT circuit 106, 118 VLC circuit 108, 120 index addition circuit for search 110 spatial filter circuit 112 1 / n circuit 114 frame memory (FM) 122 write / read control circuit 124 CPU 126 disk drive 128 disk A bus

Claims (1)

[Claims] 1. A frame memory for recording image data, a reduction means for reducing input image data to be an integral multiple of a processing unit block, and a write start address of the reduced image data by the reduction means for a processing unit block. An image recording apparatus, comprising: a recording control unit which controls the frame memory so as to be an integral multiple of.