JPH1098685A - Image information recording medium and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform comparatively easy decode processing by fetching data by every bit, adapting constitution of bit data to plural compression rules and decoding the data by a small unit. SOLUTION: A second compressed data unit CU02 of picture data PXD before compression contains five pieces of two-bit pixel data d2, d3, d4, d5, d6=(0101010101)b. In this example, five pieces of same two-bit pixel data (01)b continue. In this case, d2 to d6=(00010101)b in which an encoding header (00)b, four-bit expression (0101)b of number of continuation 'five' and contents (01)b of the pixel data is combined are the data unit CU02* of video data PXD after compression. In this case, when four to 15 pieces of the same pixel data continue, by the rule to define eight bit as one unit, the initial two bit as 00, following four bit as the number of continuous pixels and the following two bit as the pixel data, (0101010101)b of the data unit CU02 is compressed to (00010101)b of the CU02* by two bit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a recording medium for compressing and encoding digitally recorded image data such as captions or simple animations, and a method of manufacturing the same.

[0002]

2. Description of the Related Art For example, the following methods are conventionally known as methods for compressing and recording or communicating image data such as captions.

[0003] A first method is a character code conversion method in which text data is divided every other character, and a character code corresponding to the character is recorded or communicated. Current,
As character codes, two-byte codes used in Japanese and the like and one-byte codes used in English and the like are frequently used. JIS codes and shift JIS codes are used as Japanese codes, and ASCII codes and the like are used as English codes.

[0004] However, in the first method, it is necessary to provide a character font ROM corresponding to each character code on the image reproducing apparatus side, and the inconvenience that character codes that do not correspond to the character font ROM cannot be reproduced cannot be reproduced. is there. For this reason, in order for the image reproducing apparatus to support a plurality of languages, a character font ROM is required for each language.

The second method is a method of reading text data as image data and compressing the data to compress the entire data amount. As a typical example of this encoding method, a run-length compression method (run-
length compression method).

In this run-length compression method, pixel data (pixel da) obtained by scanning text data line by line is used.
In ta), when the same data is continuous, the length of the continuous pixel is converted to a run-length code, and the code-converted data is recorded or transmitted.

For example, "aaaabbbbbbbcccc"
Consider the case where a pixel data line such as "ccdd" is obtained. In the run length compression method, this is "a
4, b7, c5, d2 ", the pixel information (a, b,
c, d) and the number of continuous pixels (4,
7, 5 and 2) (run-length compression code).

[0008] As a method of further converting this run-length compression code into a binary code, a Modified Huffman Coding method (Modified Huffman Coding method) is used.
s), and arithmetic coding methods (Arithmetic Codings).

[0009]

First, "Modified Huffman code (hereinafter abbreviated as MH code)" which is standardly used in facsimile will be briefly described. However, the MH code is applied when the content of the image information, that is, the color of the pixel itself is two colors of white and black.

The MH code is obtained by allocating a binary bit code having a small number of bits (simple) to data having a high frequency of appearance (frequently used data) statistically, and data having a low frequency of occurrence (rarely). An algorithm designed to reduce the amount of data in the entire data file by allocating a binary bit code having a large number of bits (complex) to unused data) is adopted.

In this MH encoding method, if there are many types of data to be encoded, the code table itself becomes large.
Also, a number of complicated code tables corresponding to the number of data to be encoded is required in both the encoder and the decoder.

For this reason, MH coding in a multilingual system that handles various languages involves a large increase in cost for both the encoder and the decoder.

Next, the arithmetic coding method will be briefly described.

In the case of arithmetic coding, first, data is read, and the appearance frequency of each data is checked. Next, a code table is created by allocating codes having a small number of bits in the order of appearance frequency. The code table thus created is recorded (or transmitted) as data. Thereafter, the data is coded based on the code table.

In the arithmetic coding method, a code table must be recorded or transmitted, but there is an advantage that data can be created with a code table that is optimal for the contents of a file to be recorded or transmitted. Also, in the arithmetic coding method, unlike the MH coding method, it is not necessary to have a complicated code table in both the encoder and the decoder.

However, in the arithmetic coding method, when encoding a data, a code table is created.
Reading must be performed, and the decoding process is complicated.

As an image coding method other than the above two examples, there is a method disclosed in US Pat. No. 4,811,113. In this method, a flag bit indicating the number of bits of the code data length is provided before the run-length code, and a value obtained by multiplying the flag bit by an integer is encoded and decoded as the code data length.

In this method, since the data length is derived from the flag bits, a large code table is not required unlike the MH coding method. However, the hardware for deriving the code data length requires a circuit configuration inside the decoder. Is easily complicated.

Although this method can encode / decode two colors (white and black) as in the MH encoding method, it cannot directly cope with a multi-color image beyond that.

A first object of the present invention is to provide a weak point of the MH coding method (requires a large code table), a weak point of the arithmetic coding method (necessary to read data twice), and a run-length code with a flag bit. The present invention provides a method for manufacturing a recording medium on which information is recorded based on an image information encoding method capable of resolving a weak point (not compatible with multicolor image compression) of a conversion method (see US Pat. Nos. 4,811 and 113) at a practical level. is there.

A second object of the present invention is to provide the recording medium.

[0022]

In order to achieve the first object, according to the present invention, there is provided a method of manufacturing a semiconductor device comprising the same pixel in an information aggregate formed by collecting a plurality of pixel data defined by a plurality of bits. A method of manufacturing an image information recording medium on which information obtained by compressing a data block in which data is continuous as one compression unit is recorded, wherein: (a) an encoding header corresponding to the number of consecutive same pixel data in the data block of one compression unit; And encoding for encoding information of a compression unit data block composed of continuous pixel number data indicating the number of continuous same pixel data and data of a plurality of bits indicating the same pixel data itself in the data block of one compression unit. (200 in FIG. 10); and (b) a medium on which the information encoded in the encoding step is written. Master generation step of generating a static (Fig. 1
(C) the information encoded in the encoding step using the medium master created in the master creating step;
A medium production step (206 in FIG. 10) for recording on one or more image information recording media.

In order to attain the second object, the recording medium of the present invention is a data storage device comprising a plurality of pieces of pixel data defined by a plurality of bits. An image information recording medium (OD in FIG. 1) having a recording track in which information obtained by compressing a block as one compression unit is packetized in a predetermined pack unit (2048 bytes) and recorded as a data packet (sub-picture packet in FIG. 3). In the above, the data block of one compression unit (for example, CU02 * in FIG. 9) is divided into an encoded header (the first two bits, 00) corresponding to the same number of consecutive pixel data in this data block (CU02 *). Continuing pixel number data indicating the data continuation number (following 4
Bit 0101) and a plurality of bits of data (the last 2 bits 01) indicating the same pixel data itself in the data block of one compression unit; one or more of the data blocks (for example, CU01 * in FIG. 9). ~
CU05 *) to form predetermined compressed data (PXD in the lower part of FIG. 9; 32 in FIG. 3);
XD; 32) with a predetermined header (SPUH; 31) to constitute one unit of compressed data (SPU; 30);
One or more of the data packets (sub-picture data 1 in FIG. 3,
2,...) To one unit of the compressed data (SPU; 3).
0) (see the lower part of FIG. 3) on the recording track (FIG. 1).

In order to achieve the second object,
An optical disc, which is a specific embodiment of the recording medium of the present invention, uses a data block in which the same pixel data continues as one compression unit in an information aggregate formed by collecting a plurality of pixel data defined by a plurality of bits. The compressed information has a recording track for packetizing in a predetermined pack unit (2048 bytes) and recording it as a data packet (sub-picture packet in FIG. 3), and has a reproducing head having an optical head (706 in FIG. 24). An optical disk (FIG. 1 or FIG. 2) capable of reproducing the compressed information in units of the packs by a device.
4 OD), the data block of one compression unit (for example, CU02 * in FIG. 9) is combined with an encoded header (00 of the first two bits) corresponding to the same number of consecutive pixel data in this data block (CU02 *). The continuous pixel number data (the succeeding 4 bits 0101) indicating the continuous number of the same pixel data and the multi-bit data (the last 2 bits 01) indicating the same pixel data itself in the data block of one compression unit. Comprising one or more of the data blocks (for example, CU01 * to CU0 in FIG. 9).
5 *) and predetermined compressed data (PX in the lower part of FIG. 9).
D; 32) in FIG. 3; the compressed data (PX
D; 32) with a predetermined header (SPUH; 31) to form one unit of compressed data (SPU; 30); one or more data packets (sub-picture data 1, 2,... In FIG. 3). To one unit of the compressed data (SP
U; 30) and recorded on the recording track (FIG. 1) in an array corresponding to FIG. 3; when the playback device plays back the compressed information, an array of one or more data packets (FIG. 3). Are the sub-picture data 1, 2,...
06), these data packets (sub-picture data 1, 2,... In FIG. 3) are recorded on the recording track (FIG. 1) so that they can be continuously reproduced.

In the present invention, three or more types of pixel data are compressed based on at least rules 2 to 4 among rules 1 to 6 shown below. Hereinafter, a case will be described as an example where pixel data indicating each pixel dot is composed of 2 bits.

<Rule 1> When 1 to 3 pieces of the same pixel data continue: With 4 bits as one unit, the first 2 bits represent the number of continuous pixels, and the next 2 bits are used as pixel data (compressed image data PXD). .

<Example> If there is one identical continuous pixel (for example, 11), PXD = 0
1.11 If there are two identical continuous pixels (for example, 10), PXD = 1
0 · 10 If there are three identical continuous pixels (for example, 00), PXD = 1
1.00 <Rule 2> When 4 to 15 pieces of the same pixel data continue: 8 bits (bytes) are defined as one unit, and the first 2 bits are set to “0”.
0 ", the subsequent 4 bits represent the number of continuous pixels, and the following 2 bits are used as pixel data.

<Example> The number of the same continuous pixels (for example, 01) is 5
PXD = 00.0101.01 <Rule 3> When 16 to 63 pieces of the same pixel data continue: 1
With 2 bits as one unit, the first 4 bits are “000”.
0 ", the following 6 bits indicate the number of continuous pixels, and the next 2 bits are pixel data.

<Example> If there are 16 identical continuous pixels (for example, 10), PXD =
0000.010000.10 If there are 46 identical continuous pixels (for example, 11), PXD =
0000.101110.11 <Rule 4> When 64 to 255 pieces of the same pixel data continue:
The first 6 bits are “000” with 16 bits as one unit.
000 ", the subsequent 8 bits represent the number of continuous pixels, and the following 2 bits are used as pixel data.

<Example> The number of the same continuous pixels (for example, 01) is 2
If 55, PXD = 000000 111111111
01 <Rule 5> When the same pixel data continues to the end of the line (of the pixel data string to be run-length encoded): 16 bits as one unit, the first 14 bits are “00000000000000”, and the following 2 bits Is pixel data.

<Example> If the same continuous pixel (for example, 00) continues to the end of the line, PXD = 000000000000000000. If the same continuous pixel (for example, 11) continues to the end of the line, PXD = 0000000000000011. <Rule 6> At the end of one line, if the byte is not aligned, 4-bit dummy data “0000” is inserted (at the end of the compressed data for one line).

<Example> [0/1 data string is an integral multiple of 8 minus 4 bits] • 0000 In the decoding method of the present invention, the original data before encoding is restored by performing the inverse operation of the above encoding rule. I have.

[0033]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An encoding method and a decoding method according to an embodiment of the present invention will be described below with reference to the drawings. In order to avoid redundant description, common reference numerals are used for functionally common parts in a plurality of drawings.

FIGS. 1 to 27 are diagrams for explaining an image information encoding / decoding system according to an embodiment of the present invention.

FIG. 1 schematically shows a recording data structure of an optical disk OD as an example of an information storage medium to which the present invention can be applied.

This optical disk OD has, for example, about 5
It is a double-sided laminated disk with a storage capacity of G bytes,
A number of recording tracks are arranged between a lead-in area on the inner circumference side of the disc and a lead-out area on the outer circumference side of the disc. Each track is composed of a large number of logical sectors, and various information (appropriately compressed digital data) is stored in each sector.

FIG. 2 shows an example of the logical structure of data recorded on the optical disk of FIG. That is, a system area for storing system data used in the disk OD, a volume management information area, and a plurality of file areas are formed in the aggregate of a plurality of logical sectors in FIG.

Of the plurality of file areas, for example, file 1 includes main video information (VIDEO in the drawing) and sub-video information (S in the drawing) having auxiliary contents for the main video.
UB-PICTURE), audio information (AUDI in the figure)
O), playback information (PLAYBACK INF in the figure)
O. ) Etc. are included.

FIG. 3 illustrates the logical structure of a pack of encoded (run-length compressed) sub-picture information in the data structure illustrated in FIG.

As shown in the upper part of FIG. 3, one pack of the sub-picture information included in the video data is composed of, for example, 2048 bytes. One pack of the sub-picture information includes one or more sub-picture packets after the header of the first pack. The first sub-picture packet includes run-length compressed sub-picture data (SP DATA1) after the header of the packet. Similarly, the second sub-picture packet has run-length compressed sub-picture data (SP DATA2) after the header of the packet.
Contains.

A plurality of such sub-picture data (SP D
ATA1, SP DATA2,...) Are collected for one unit (one unit) of run-length compression, that is, the sub-picture data unit 30 is provided with a sub-picture unit header 31. After the sub-picture unit header 31, 1
Video data for a unit (for example, 1
Pixel data 32 obtained by run-length-compressing horizontal line data) follows.

In other words, the run-length compressed data 30 for one unit is composed of one or more sub-picture data sub-picture data portions (SP DATA1, SP DATA2,...).
Is formed by a collection of The sub-picture data unit 30 includes a sub-picture unit header 31 in which various parameters for sub-picture display are recorded, and display data (compressed pixel data) 32 composed of a run-length code.

FIG. 4 illustrates the contents of the sub-picture unit header 31 in the run-length compressed data 30 for one unit illustrated in FIG. Here, a description will be given of data of a sub-video (for example, subtitles corresponding to a movie scene of the main video) recorded and transmitted (communicated) together with a main video (for example, a video main body of a movie).

As shown in FIG. 4, the sub-picture unit header 31 includes a start address SPDADDR of pixel data (display data) 32 of the sub-picture, an end address SPEDADR of the pixel data 32, and a picture data of the pixel data 32 on the TV screen. Display start position and display range (width and height) SPDS
SIZE and background color SPCHI specified by the system
And the sub-picture color SPCINFO specified by the system
And the palette color number S of the highlight color specified by the system
PADJINFO, decoration information SPMOD of sub-picture pixel data 32, and sub-picture (SP) for main picture (MP)
, The start timing of the sub-picture (corresponding to the frame number of the main picture) SPDST, and the start address SPLine1-S of the decode data for each line
Line N is recorded.

More specifically, as shown in the lower part of FIG. 4, various parameters (such as SPDDADR) having the following contents are recorded in the sub-picture unit header 31: (1) This header (2) start address information (SPDADDR: relative address from the head of the header) of display data (pixel data of sub-picture) following this; and (2) end address information (SPEDA) of this display data.
(3) information (SP) indicating a display start position and a display range (width and height) of the display data on the monitor screen;
(4) information (SPCH) indicating the background color (16-color color palette number set in the story information table or display control sequence table) specified by the system.
(5) Information (SPC) indicating the sub-picture color specified by the system (16-color color palette number set in the story information table or display control sequence table)
(INFO) and; (6) information (SPAJ) indicating the sub-picture emphasized color (color palette number set in the story information table or the display control sequence table) specified by the system.
(7) sub-picture image mode information (SPMOD) designated by the system and indicating non-interlaced field mode or interlaced frame mode, etc .; and (compression target pixel data is composed of various bit numbers) In this case, the number of bits of the pixel data can be specified by the content of the mode information.); (8) Information (SPCONT) indicating the mixture ratio of the sub-picture and the main picture specified by the system; (9) ) The display start timing of the sub-picture is determined by the frame number of the main picture (for example, the I-picture frame number of MPEG)
(10) Information (SPlin1) indicating the start address (relative address from the head of the sub-picture unit header) of the encoded data of the first line of the sub-picture; Information (SPlinN) indicating the start address of the encoded data on the Nth line (relative address from the head of the sub-picture unit header).

The information SPCONT indicating the mixture ratio of the sub-picture and the main picture represents the mixture ratio of the sub-picture by (system set value) / 255, and (255-set value) / 255.
Indicates the mixture ratio of the main image.

In the sub-picture unit header 31, the start address (SPLin) of the decode data for each line
e1 to SPlineN). Therefore, by changing the designation of the decoding start line according to an instruction from a microcomputer (MPU or CPU) on the decoder side, scrolling of only the sub-picture on the display screen can be realized. (This scroll will be described later with reference to FIG. 21.) By the way, the sub-picture unit header 31 has a field / frame mode (showing how the sub-picture corresponds to a TV field / frame of the NTSC system). SPMOD) can be recorded.

Normally, bit "0" is written in this field / frame mode recording unit (SPMOD). On the decoder side receiving such a sub-picture data unit 30, the bit "0" determines that the mode is the frame mode (non-interlace mode).
The received code data is decoded line by line. Then, a decoded image as illustrated in the lower left of FIG. 8 is output from the decoder, and is displayed on a display screen such as a monitor or a television (TV).

On the other hand, if bit "1" is written in the field / frame mode recording unit (SPMOD), the decoder determines that the mode is the field mode (interlace mode). In this case, after the code data is decoded line by line, the same data is continuously output for two lines as illustrated in the lower right of FIG. Then, a screen corresponding to the TV interlace mode is obtained. As a result, although the image quality is lower than that in the frame mode (non-interlace mode), an image having twice the amount of the same data amount as the frame mode can be displayed.

The pixel data (run-length data) 32 of the sub-picture shown in FIG. 3 or FIG. 4 satisfies any one of the run-length compression rules 1 to 6 or the run-length compression rules 11 to 15 shown in FIG. Depending on what is applied
The data length (variable length) of one unit is determined. Then, encoding (run-length compression) and decoding (run-length decompression) are performed with the determined data length.

Rules 1 to 6 in FIG. 5 are used when the pixel data to be compressed has a plurality of bits (here, 2 bits), and rules 11 to 15 in FIG. Used if

Which of the run-length compression rules 1 to 6 or the run-length compression rules 11 to 15 is used is determined by the contents of the parameter SPMOD in the sub-picture unit header 31 (see the vicinity of the center of the lower table in FIG. 4). (Such as a bit width flag). For example, when the bit width flag of the parameter SPMOD is “1”, the pixel data to be run-length compressed is 2-bit data, and rules 1 to 6 in FIG. 5 are used. On the other hand, when the bit width flag of the parameter SPMOD is “0”, the pixel data to be run-length compressed is 1-bit data, and the rules 11 to 15 in FIG. 6 are used.

Now, when the pixel data can have a 1, 2, 3 or 4 bit configuration, four types of compression rule groups A, B, C, D are prepared corresponding to these bit configuration values. Assume that In this case, the parameter SPMOD
Is a 2-bit flag, the flag “00” specifies 1-bit pixel data using rule group A, the flag “01” specifies 2-bit pixel data using rule group B, and the flag “10” specifies rule data. The 3-bit pixel data using the group C can be specified, and the 4-bit pixel data using the rule group D can be specified by the flag “11”. Here, for the compression rule group A, the rules 11 to 15 in FIG.
Can use rules 1 to 6 in FIG. The compression rule groups C and D are obtained by appropriately changing the encoding header, the number of continuous pixels, the configuration bit value of pixel data, and the number of rules in FIG.

FIG. 5 shows a case where the sub-picture pixel data (run-length data) 32 illustrated in FIG. 4 is composed of a plurality of bits (here, 2 bits) of pixel data.
4 is a diagram for explaining run length compression rules 1 to 6 employed in the encoding method according to one embodiment of the present invention.

FIG. 9 shows a case where the sub-picture pixel data (run-length data) 32 illustrated in FIG. 4 is composed of 2-bit pixel data.
FIG. 6 is a diagram for specifically explaining No. 6;

According to rule 1 shown in the first column of FIG. 5, when one to three identical pixels continue, one unit of encoded (run-length compressed) data is constituted by 4-bit data. In this case, the first two bits represent the number of continuous pixels, and the following two bits represent pixel data (such as pixel color information).

For example, the first compressed data unit CU01 of the video data PXD before compression shown in the upper part of FIG.
Two 2-bit pixel data d0, d1 = (0000) b
(B indicates binary). In this example, two identical 2-bit pixel data (00) b are continuous (continuous).

In this case, as shown in the lower part of FIG. 9, d0 and d1 = (1000) b which connect the 2-bit display (10) b of the continuation number "2" and the content (00) b of the pixel data are obtained. ,
It becomes the data unit CU01 * of the video data PXD after compression.

In other words, according to rule 1, the data unit C
(0000) b of U01 is (1) of data unit CU01 *.
000) b. In this example, no substantial bit length compression is obtained, but for example, the same pixel (00)
If b is three consecutive CU01 = (000000) b, CU01 * = (1100) b after compression, and 2
A bit compression effect is obtained.

According to rule 2 shown in the second column of FIG. 5, when 4 to 15 identical pixels continue, one unit of encoded data is constituted by 8-bit data. In this case, the first two bits represent a coded header indicating that it is based on rule 2, and the following 4
The bit represents the number of continuous pixels, and the subsequent two bits represent pixel data.

For example, the second compressed data unit CU02 of the video data PXD before compression shown in the upper part of FIG.
Are five 2-bit pixel data d2, d3, d4, d
5, d6 = (0101010101) b.
In this example, the same 2-bit pixel data (01) b is 5
It is continuous (continuous).

In this case, as shown in the lower part of FIG. 9, the encoded header (00) b, the 4-bit display (0101) b of the continuation number "5", and the content (01) b of the pixel data are connected. d2 to d6 = (00010101) b are the data units CU02 * of the compressed video data PXD.

In other words, according to rule 2, the data unit C
(0101010101) b of U02 (10-bit length)
Is (00010101) b (8) of the data unit CU02 *.
(Bit length). In this example, the effective bit length compression amount is only 2 bits from 10 bits to 8 bits. However, when the continuation number is, for example, 15 (30 bits long since 15 CU02 01s are continuous), this is 8 bits. Of compressed data (CU02 * = 00111101)
A compression effect of 22 bits can be obtained for 30 bits.
That is, the bit compression effect based on Rule 2 is greater than that of Rule 1. However, rule 1 is also required to support run-length compression of a fine image with high resolution.

According to rule 3 shown in the third column of FIG. 5, when 16 to 63 identical pixels continue, one unit of encoded data is constituted by 12-bit data. In this case, the first 4 bits represent an encoding header indicating that the rule is based on Rule 3, the following 6 bits represent the number of continuous pixels, and the subsequent 2 bits represent pixel data.

For example, the third compressed data unit CU03 of the video data PXD before compression shown in the upper part of FIG.
Are 16 2-bit pixel data d7 to d22 = (10
1010... 1010) b. In this example, 16 pieces of the same 2-bit pixel data (10) b are continuous (continuous).

In this case, as shown in the lower part of FIG. 9, the encoded header (0000) b, the 6-bit display (010000) b of the number of continuations "16", and the content of the pixel data (10) b
And d7 to d22 = (000000100001)
0) b is the data unit CU of the compressed video data PXD
03 *.

In other words, according to rule 3, the data unit C
(101010... 1010) b (32-bit length) of U03 is (000000001000) of the data unit CU03 *.
010) b (12-bit length). In this example, the substantial bit length compression amount is 20 bits from 32 bits to 12 bits, but the continuation number is, for example, 63 (CU0
In the case of 63 consecutive 10s of 3 and a length of 126 bits, this is 12-bit compressed data (CU03 * = 00).
0011111110), and a compression effect of 114 bits can be obtained for 126 bits. That is, the bit compression effect based on Rule 3 is greater than that of Rule 2.

According to rule 4 shown in the fourth column of FIG. 5, when 64 to 255 identical pixels continue, one unit of encoded data is constituted by 16-bit data. In this case, the first 6 bits represent a coded header indicating that it is based on rule 4,
The subsequent 8 bits represent the number of continuous pixels, and the subsequent 2 bits represent pixel data.

For example, the fourth compressed data unit CU04 of the video data PXD before compression shown in the upper part of FIG.
Are 69 2-bit pixel data d23 to d91 = (1
11111... 1111) b. In this example, 69 pieces of the same 2-bit pixel data (11) b are continuous (continuous).

In this case, as shown in the lower part of FIG. 9, the encoded header (000000) b, the 8-bit display (00100101) b of the continuation number “69”, and the content (11) b of the pixel data are connected. d23 to d91 = (000000)
0010010111) b is the compressed video data PX
D data unit CU04 *.

In other words, according to rule 4, the data unit C
(111111... 1111) b (138-bit length) of U04 is (00000000) of data unit CU04 *.
10010111) converted to b (16-bit length).
In this example, the substantial bit length compression amount is 122 bits from 138 bits to 16 bits, but the continuation number is, for example, 255 (because 11 of CU01 continue 255, 51
In the case of (0-bit length), this becomes 16-bit compressed data (CU04 * = 000001111111111), and a 494-bit compression effect is obtained for 510 bits. That is, the bit compression effect based on Rule 4 is
Larger than that of Rule 3.

According to rule 5 shown in the fifth column in FIG. 5, when the same pixel continues from the switching point of the encoded data unit to the end of the line, one unit of encoded data is constituted by 16-bit data. In this case, the first 14 bits represent an encoded header indicating that the data is based on rule 5, and the following 2 bits represent pixel data.

For example, the fifth compressed data unit CU05 of the video data PXD before compression shown in the upper part of FIG.
Is one or more 2-bit pixel data d92 to dn = (0
00000... 0000) b. In this example, the same two-bit pixel data (00) b is continuous (continuous) in a finite number. However, in rule 5, the number of continuous pixels may be one or more.

In this case, as shown in the lower part of FIG. 9, d92 to dn = (0) connecting the encoded header (00000000000000) b and the content (00) b of the pixel data.
000000000000000000) b is the data unit CU05 * of the compressed video data PXD.

In other words, according to rule 5, the data unit C
(00000000 ... 0000) b (unspecified bit length) of U05 is (00000000) of data unit CU05 *.
00000000) b (16 bits long).
In rule 5, the same pixel continuation number up to the line end is 16
With a bit length or more, a compression effect can be obtained.

According to rule 6 shown in the sixth column of FIG. 5, when one pixel line in which data to be encoded is arranged ends, the length of one line of compressed data PXD is not an integral multiple of 8 bits (ie, When the data is not byte-aligned, 4-bit dummy data is added so that the compressed data PXD for one line is in units of bytes (that is, byte-aligned).

For example, the data units CU01 * to CU05 * of the compressed video data PXD shown in the lower part of FIG.
Is always an integral multiple of 4 bits, but is not necessarily an integral multiple of 8 bits.

For example, data units CU01 * to CU05
If the total bit length of * is 1020 bits and 4 bits are insufficient for byte alignment, as shown in the lower part of FIG. 9, 4-bit dummy data CU06 * =
(0000) b is added to the end of the 1,020 bits to generate a byte-aligned 1024-bit data unit CU0.
1 * to CU06 * are output.

Note that the 2-bit pixel data is not necessarily 4 bits.
The present invention is not limited to the display of the types of pixel colors. For example, pixel data (00) b represents a background pixel of a sub-picture,
The pixel data (01) b represents a sub-picture pattern pixel,
The pixel data (10) b represents the first emphasized pixel of the sub-picture,
The pixel data (11) b may represent the second emphasized pixel of the sub-picture.

If the number of bits constituting the pixel data is larger, another type of sub-picture pixel can be specified. For example, when the pixel data is composed of 3-bit (000) b to (111) b, the maximum of eight types of pixel colors +
Pixel type (emphasis effect) can be specified.

FIG. 6 shows a case where the sub-picture pixel data (run-length data) 32 illustrated in FIG. 4 is composed of 1-bit pixel data, which is employed in the encoding method according to another embodiment of the present invention. This is a description of run-length compression rules 11 to 15 shown in FIG.

According to rule 11 shown in the first column of FIG. 6, when one to seven identical pixels continue, one unit of encoded (run-length compressed) data is constituted by 4-bit data. In this case, the first three bits indicate the number of continuous pixels, and the next one bit indicates pixel data (eg, information on pixel type). For example, if the 1-bit pixel data is "0", it indicates a background pixel of the sub-picture, and if it is "1", it indicates a pattern pixel of the sub-picture.

According to rule 12 shown in the second column of FIG. 6, when 8 to 15 identical pixels continue, one unit of encoded data is constituted by 8-bit data. In this case, the first three bits represent an encoding header (for example, 000) indicating that the rule is based on rule 12, the following four bits represent the number of continuous pixels, and the subsequent one bit represents pixel data.

According to rule 13 shown in the third column of FIG. 6, when 16 to 127 identical pixels continue, one unit of encoded data is constituted by 12-bit data. In this case, the first 4
A bit indicates an encoding header (for example, 0000) indicating that the rule is based on rule 13, the next 7 bits indicate the number of continuous pixels, and the subsequent 1 bit indicates pixel data.

According to rule 14 shown in the fourth column of FIG. 6, when the same pixel continues from the switching point of the encoded data unit to the end of the line, one unit of encoded data is constituted by 8-bit data. In this case, the first seven bits are used for rule 1
4 (for example, 0000)
000), and the following 1 bit represents pixel data.

According to rule 15 shown in the fifth column of FIG. 6, when one pixel line in which data to be encoded is arranged ends, the length of one line of compressed data PXD is not an integral multiple of 8 bits (ie, When the data is not byte-aligned, 4-bit dummy data is added so that the compressed data PXD for one line is in units of bytes (that is, byte-aligned).

Next, an image encoding method (an encoding method using run-length compression encoding) will be specifically described with reference to FIG.

FIG. 7 shows that the pixel data constituting the sub-picture pixel data (run-length data) 32 illustrated in FIG.
For example, it is composed of first to ninth lines, and 2
Pixels having a bit configuration (having a maximum of four types of contents) are arranged, and character patterns "A" and "B" are represented by 2-bit pixels on each line. In this case, how the pixel data of each line is encoded (run-length compressed) will be specifically described.

As exemplified in the upper part of FIG. 7, an image serving as a source is composed of three types (up to four types) of pixel data. That is, the 2-bit image data (00) b indicates the pixel color of the background of the sub-picture, and the 2-bit image data (01) b indicates the pixel colors of characters "A" and "B" in the sub-picture. The emphasized pixel colors for the sub-picture characters "A" and "B" are indicated by the 2-bit image data (10) b.

When an original image including the characters "A" and "B" is scanned by a scanner or the like, these character patterns are read in units of one pixel from left to right for each scanning line. The video data thus read is input to an encoder (200 in the embodiment of FIG. 10 described later) that performs run-length compression based on the present invention.

This encoder uses the rule 1 described in FIG.
-A microcomputer (MPU or C) that runs software that executes run-length compression based on Rule 6.
PU). This encoder software will be described later with reference to the flowcharts of FIGS.

The encoding process for run-length compressing the sequential bit string of the character patterns "A" and "B" read in units of one pixel will be described below.

In the example shown in FIG. 7, since it is assumed that the source image has three pixel colors, the video data to be encoded (sequential bit strings of character patterns "A" and "B") are the background pixel colors. "." Is replaced with 2-bit pixel data (0
0) b, the character pixel color “#” is represented by 2-bit pixel data (01) b, and the emphasized pixel color “o” is represented by 2-bit pixel data (10) b. This pixel data (00,
The bit number (= 2) such as 01 is sometimes called a pixel width.

For the sake of simplicity, in the example of FIG. 7, the display width of the video data (sub-video data) to be encoded is 16 pixels, and the number of scanning lines (display height) is 9 lines.

First, pixel data (sub-picture data) obtained from the scanner is temporarily converted by a microcomputer into a run length value before compression.

That is, taking the first line at the top of FIG. 7 as an example, three continuous images “...” Are converted into (· * 3), and one subsequent “o” is converted into (o). * 1), one subsequent "#" is converted to (# * 1), one subsequent "o" is converted to (o * 1), and the subsequent triple image "." .. "is converted to (. * 3), the subsequent one" o "is converted to (o * 1), and the subsequent quadruple image"##
"##" is converted to (# * 4), followed by one "o"
Is converted to (o * 1), and the last "."
Is converted to 1).

As a result, as shown in the middle part of FIG. 7, the pre-compression run-length data of the first line is “· * 3 / o *
1 / # * 1 / o * 1 / · * 3 / o * 1 / # * 4 / o * 1
/.*1 ". This data is composed of a combination of image information such as a character pixel color and the number of continuous pixels indicating the number of continuations.

Similarly, the pixel data strings on the second to ninth lines in the upper part of FIG. 7 become run-length data strings before compression as shown in the second to ninth lines in the middle part of FIG.

Here, paying attention to the data of the first line, since three background pixel colors “•” continue from the start of the line, the compression rule 1 of FIG. 5 is applied. As a result, the first "..." of the first line, that is, (· * 3)
Is 2 bits (11) representing “3” and the background pixel color “•”
Is encoded into (1100) obtained by combining (00) with.

Since the next data on the first line has one "o", the rule 1 is also applied. As a result, [o] next to the first line, that is, (o * 1) is 2 representing “1”.
It is encoded to (0110) which is a combination of bit (01) and (10) representing the emphasized pixel color “o”.

Since the next data has only one "#", the rule 1 is also applied. As a result, the next [#] on the first line, that is, (# * 1) is (0101) obtained by combining two bits (01) representing "1" and (01) representing the character pixel color "#". Encoded. (The portion related to # is surrounded by broken lines in the middle and lower parts of FIG. 7.) Similarly, (o * 1) is (0110)
, (* 3) is encoded to (1100), and (o * 1) is encoded to (0110).

Since the data following the first line has four "#" s, the compression rule 2 shown in FIG. 5 is applied. As a result, this [#] on the first line, that is, (# * 4) is a 2-bit header (00) indicating that rule 2 has been applied.
And 4 bits (0100) representing the number of continuous pixels “4”;
A combination of (01) representing the character pixel color “#” (0
0010001). (The portion related to # is surrounded by a broken line.) Since the data subsequent to the first line has one "o", Rule 1 is applied. As a result, this [o], that is, (o * 1)
Represents two bits (01) representing “1” and an emphasized pixel color “o”
Is encoded to (0110) which is a combination of (10) and

Since the last data on the first line has one ".", Rule 1 is applied. As a result, this [•], that is, (• * 1) is a combination of two bits (01) representing “1” and (00) representing the background pixel color “•” (01).
00).

As described above, the run-length data before compression for the first line ". * 3 / o * 1 / # * 1 / o * 1 /
* 3 / o * 1 / # * 4 / o * 1 /.* 1 "is (11
00) (0110) (0101) (0110) (110
0) (0110) (00010001) (0110)
Run-length compression is performed as in (0100), and encoding of the first line is completed.

In the same manner, encoding proceeds up to the eighth line. In the ninth line, one line is occupied by the same background pixel color “•”. In this case, FIG.
Compression rule 5 is applied. As a result, the pre-compression run-length data “• * 16” on the ninth line indicates that the same background pixel color “•” continues to the line end 1
4-bit header (000000000000000)
And 2-bit pixel data (0
0) and 16-bit (00000000)
0000000000).

The encoding based on the rule 5 is as follows.
It is also applied when the data to be compressed starts from the middle of the line and continues to the end of the line.

FIG. 10 explains the flow from mass production to reproduction on the user side of a high-density optical disk having image information encoded according to the present invention;
Broadcast / encoding of image information encoded according to the present invention
It is a block diagram explaining the flow from cable distribution to reception / reproduction in a user / subscriber.

For example, when the pre-compression run-length data as shown in the middle part of FIG. 7 is input to the encoder 200 of FIG. 10, the encoder 200 performs the input by software processing based on the compression rules 1 to 6 of FIG. The resulting data is run-length compressed (encoded).

When data having a logical configuration as shown in FIG. 2 is recorded on the optical disc OD as shown in FIG.
The run-length compression processing (encoding processing) by the 0 encoder 200 is performed on the sub-picture data of FIG.

Various data necessary for completing the optical disc OD are also input to the encoder 200 shown in FIG. These data are, for example, MPEG (Mortion
The compressed digital data is compressed according to the standards of the Picture Expert Group and the laser cutting machine 202
Or sent to the modulator / transmitter 210.

In the laser cutting machine 202, MPEG compressed data from the encoder 200 is cut on a mother disk (not shown), and an optical disk master 204 is manufactured.

Mass production facility 20 for two-layer high-density optical disc
In step 6, the master 204 is used as a template to transfer the master information to a laser light reflecting film on a polycarbonate substrate having a thickness of 0.6 mm, for example. A large amount of two polycarbonate substrates onto which different pieces of master information have been transferred are bonded together to form a 1.2 mm thick double-sided optical disk (or single-sided reading double-sided disk).

The bonded high-density optical disk OD mass-produced in the facility 206 is distributed to various markets and reaches the user.

The distributed disk OD is reproduced by the reproduction device 300 of the user. The device 300 includes a decoder 101 for restoring data encoded by the encoder 200 to original information. The information decoded by the decoder 101 is sent to, for example, a user's monitor TV and is visualized. Thus, the end user can enjoy the original video information from the mass-distributed disc OD.

On the other hand, the compressed information sent from the encoder 200 to the modulator / transmitter 210 is modulated according to a predetermined standard and transmitted. For example, the compressed video information from the encoder 200 is satellite broadcast (212) together with the corresponding audio information. Alternatively, the compressed video information from the encoder 200 is transmitted by cable (212) together with the corresponding audio information.

The compressed video / audio information broadcast or transmitted by cable is received by the receiver / demodulator 400 of the user or subscriber. The receiver / demodulator 400 includes a decoder 101 for restoring data encoded by the encoder 200 to original information. Decoder 101
Is decoded, for example, by the user's monitor TV.
To be visualized. Thus, the end user can enjoy the original video information from the compressed video information broadcast or transmitted by cable.

FIG. 11 is a block diagram showing an embodiment (non-interlaced specification) of decoder hardware for executing image decoding (run-length expansion) based on the present invention. Run-length compressed sub-picture data SP
Decoder 1 for decoding D (corresponding to data 32 in FIG. 3)
01 (see FIG. 10) can be configured as shown in FIG.

Hereinafter, a sub-picture data decoder for extending the length of a signal including the run-length-compressed pixel data in the format shown in FIG. 4 will be described with reference to FIG.

As shown in FIG. 11, sub-picture decoder 101 receives data I / O to which sub-picture data SPD is input.
O102; memory 10 for storing sub-picture data SPD
8, a memory control unit 105 for controlling the read / write operation of the memory 108; and a continuous code length of one unit (one block) from the run information of the code data (run-length compressed pixel data) read from the memory 108. (Encoded header), and a continuation code length detection unit 106 for outputting the continuation code length separation information; and a code data cutout for extracting one block of code data according to the information from the continuation code length detection unit 106. A dividing unit 103; a signal output from the code data dividing unit 103 and indicating run information of one compression unit;
06 and the data bit "0"
Indicates the number of consecutive "0" bits (period signal) from the beginning of the code data for one block from the beginning.
And a run length setting unit 107 that calculates the number of continuous pixels in one block from these signals; and receives the pixel color information from the code data separation unit 103 and the period signal output from the run length setting unit 107. , Pixel color output unit 104 that outputs color information only during that period (Fast-in / Fast-out type)
; The sub-picture data SPD read from the memory 108
The microcomputer 112 reads the header data therein (see FIG. 4) and performs various processing settings and controls based on the read data; an address control unit 109 that controls a read / write address of the memory 108; An insufficient pixel color setting unit 111 in which color information is set by the microcomputer 112;
It comprises a display validity permitting section 110 for determining a display area when a sub-picture is displayed on a V screen or the like.

The above description will be described again in another way.
It looks like this: That is, as shown in FIG. 11, the run-length compressed sub-picture data SPD is
Via O102, it is sent to the bus inside the decoder 101. The data SPD sent to the bus is sent to the memory 108 via the memory control unit 105, where it is stored. The internal bus of the decoder 101 is connected to the code data separating unit 103, the continuous code length detecting unit 106, and the microcomputer (MPU or CPU) 112.

The sub-picture unit header 31 of the sub-picture data read from the memory 108 is read by the microcomputer 112. Microcomputer 1
12 sets the decoding start address (SPDDDR) in the address control unit 109 from the read header 31 based on the various parameters shown in FIG. The information (SPDSIZE) with the display height is set, and the display width (the number of dots on a line) of the sub-picture is set in the code data separating unit 103. The set various information is stored in each section (109, 110, 1).
03) is stored in the internal register. After that, the various information stored in the register is transferred to the microcomputer 11
2 allows access.

The address control unit 109 accesses the memory 108 via the memory control unit 105 based on the decoding start address (SPDDDR) set in the register, and starts reading sub-picture data to be decoded. The sub-picture data thus read from the memory 108 is supplied to the code data cutout unit 103 and the continuous code length detection unit 106.

Run-length compressed sub-picture data SP
The coded header of D (2 to 14 bits in rules 2 to 5 in FIG. 5) is detected by the continuation code length detection unit 106, and the number of continuation pixels of the same pixel data in the data SPD is determined by the continuation code length detection unit 106. Run length setting unit 1 based on signal
07.

That is, the continuation code length detection unit 106
By counting the number of "0" bits of the data read from the memory 108, the encoded header (see FIG. 5) is detected. The detecting unit 106 supplies the code data separating unit 103 with the information SEP. I
NFO. give.

The code data separating section 103 receives the provided separating information SEP. INFO. , The number of continuous pixels (run information) is set in the run length setting unit 107, and the pixel data (SEPARATED DATA; here, the pixel color) is set in the FIFO type pixel color output unit 104. At this time, the code data separating unit 103 counts the number of pixels of the sub-picture data, and compares the pixel count value with the display width of the sub-picture (the number of pixels in one line).

If byte-alignment is not performed when decoding of one line is completed (that is, the data bit length of one line is not a multiple of 8), the code data separating unit 103 outputs the last 4 bits on the line. Bit data is regarded as dummy data added at the time of encoding, and is discarded.

The run-length setting unit 107 outputs a pixel color output unit 104 based on the number of continuous pixels (run information), a pixel dot clock (DOTCLK), and a horizontal / vertical synchronization signal (H-SYNC / V-SYNC). Is supplied with a signal (PERIOD SIGNAL) for outputting pixel data. Then, while the pixel data output signal (PERIOD SIGNAL) is active (that is, during the period of outputting the same pixel color), the pixel color output unit 104 decodes the pixel data from the code data separation unit 103 into a decoded display. Output as data.

At this time, if the decoding start line has been changed by an instruction from the microcomputer 112, there may be a line without run information. In this case, the missing pixel color setting unit 111 supplies the preset missing pixel color data (COLOR INFO.) To the pixel color output unit 104. Then, while the line data without the run information is given to the code data separating unit 103, the pixel color output unit 104 outputs the insufficient pixel color setting unit 111.
And outputs the missing pixel color data (COLOR INFO.).

That is, in the case of the decoder 101 in FIG. 11, if there is no image data in the input sub-picture data SPD, the microcomputer 112 sets the insufficient pixel color information to the insufficient pixel color setting section 111. It has become.

A display enable signal (Display Enable) for determining which position on the monitor screen (not shown) the decoded sub-picture is to be displayed is supplied to the pixel color output unit 104 in the horizontal / vertical synchronization of the sub-picture image. Synchronized with the signal, it is provided from a display activation permitting section (Display Activator) 110. Further, based on a color information instruction from the microcomputer 112, a color switching signal is sent from the permission unit 110 to the output unit 104.

The address control unit 109 sets the processing by the microcomputer 112,
Address data and various timing signals are transmitted to the continuation code length detection unit 106, the code data separation unit 103, and the run length setting unit 107.

When a pack of sub-picture data SPD is fetched via data I / O section 102 and stored in memory 108, the contents of the pack header (decoding start address, decoding end address, display The microcomputer 112 reads the start position, display width, display height, and the like. The microcomputer 112 sets a decode start address, a decode end address, a display start position, a display width, a display height, and the like in the display validity permitting unit 110 based on the read content.
At this time, the number of bits of the compressed pixel data (here, the pixel data is 2 bits) is determined as shown in FIG.
Can be determined by the content of the sub-picture unit header 31.

The operation of the decoder 101 shown in FIG. 11 will be described below in the case where the compressed pixel data has a 2-bit configuration (use rules are rules 1 to 6 in FIG. 5).

When the microcomputer 112 sets a decode start address, the address control unit 1
09 sends the address data corresponding to the memory control unit 105 and sends a read start signal to the continuous code length detection unit 106.

The continuation code length detecting section 106 sends a read signal to the memory control section 105 in response to the read start signal sent thereto, and sends encoded data (compressed sub-picture data 3).
Read 2). Then, in this detection unit 106,
It is checked whether all the upper two bits of the read data are "0".

If they are not "0", it is determined that the block length of the compression unit is 4 bits (see rule 1 in FIG. 5).

If those (upper 2 bits) are “0”, the subsequent 2 bits (upper 4 bits) are checked. If they are not “0”, it is determined that the block length of the compression unit is 8 bits (see rule 2 in FIG. 5).

If these (upper 4 bits) are "0", the next 2 bits (upper 6 bits) are checked. If they are not “0”, it is determined that the block length of the compression unit is 12 bits (see rule 3 in FIG. 5).

If these (upper 6 bits) are “0”, the subsequent 8 bits (upper 14 bits) are checked. If they are not “0”, it is determined that the block length of the compression unit is 16 bits (Rule 4 in FIG. 5).
reference).

If these (higher 14 bits) are "0", it is determined that the block length of the compression unit is 16 bits and the same pixel data continues until the line end (rule 5 in FIG. 5). reference).

If the number of bits of the pixel data read up to the line end is an integral multiple of eight, the pixel data is left unchanged.
If it is not an integral multiple of, it is determined that 4-bit dummy data is necessary at the end of the read data to realize byte alignment (see rule 6 in FIG. 5).

The code data separating section 103 stores the data in the memory 1 based on the result of the determination by the continuous code length detecting section 106.
08, one block (one compression unit) of the sub-picture data 32 is extracted. Then, in the separation unit 103, the extracted data for one block is separated into the number of continuous pixels and pixel data (such as pixel color information). The data of the number of continuous pixels (RUN INFO.) Thus divided is sent to the run length setting unit 107, and the divided pixel data (SEPARATED DATA) is outputted to the pixel color output unit 10.
4

On the other hand, the display validity permitting section 110 receives the display start position information received from the microcomputer 112,
A pixel dot clock (PIXEL-DOT) supplied from outside the device according to the display width information and the display height information.
CLK), a horizontal synchronizing signal (H-SYNC), and a vertical synchronizing signal (V-SYNC) to generate a display permission signal (enable signal) for designating a sub-video display period.
This display permission signal is output to run length setting section 107.

The run length setting unit 107 outputs a signal from the continuation code length detection unit 106 indicating whether the current block data continues to the line end, and a signal from the code data separation unit 103. Continuation pixel data (R
UN INFO. ) Is sent. Run length setting unit 107
Determines the number of pixel dots covered by the block being decoded based on the signal from the detection unit 106 and the data from the separation unit 103, and during a period corresponding to this number of dots,
It is configured to output a display permission signal (output enable signal) to the pixel color output unit 104.

The pixel color output unit 104 includes the run length setting unit 10
7 during the signal reception period, and during that period, the pixel color information received from the code data separation unit 103 is transmitted to the pixel dot clock (PIXEL-DOT CL).
In synchronization with K), the data is transmitted to a display device (not shown) as decoded display data. That is, the same display data as the number of continuous dots of the pixel pattern of the block being decoded is output from the pixel color output unit 104.

When the continuation code length detection unit 106 determines that the encoded data is the same pixel color data until the line end, the continuation code length detection unit 106 sends the continuation code length 1 to the code data separation unit 103.
A signal for 6 bits is output, and a signal indicating that the pixel color data is the same until the line end is output to the run length setting unit 107.

When the run length setting unit 107 receives the signal from the detection unit 106, the run length setting unit 107 sets the pixel color so that the color information of the encoded data keeps the enable state until the horizontal synchronization signal H-SYNC becomes inactive. An output enable signal (period signal) is output to the output unit 104.

When the microcomputer 112 changes the decoding start line in order to scroll the display contents of the sub-picture, the data line to be used for decoding does not exist in the preset display area (that is, the decoding line). May be insufficient).

In order to cope with such a case, the decoder 101 in FIG. 11 prepares pixel color data for filling the missing lines in advance. Then, when a line shortage is actually detected, the display mode is switched to the display mode of the insufficient pixel color data. Specifically, when a data end signal is given from the address control unit 109 to the display validity permission unit 110, the permission unit 110 sends a color switching signal (COL SW SIGNAL) to the pixel color output unit 104. In response to the switching signal, the pixel color output unit 104 switches the decoded output of the pixel color data from the code data to the decoded output of the color information (COLOR INFO.) From the insufficient pixel color setting unit 110. This switching state is maintained during the display period of the insufficient line (DISPLAY ENABLE = active).

When the line shortage occurs, instead of using the insufficient pixel color data, the decoding operation can be stopped during that time.

More specifically, for example, when a data end signal is input from the address control section 109 to the display validity permitting section 110, the permitting section 110 outputs to the pixel color output section 104 a color switching signal for designating display suspension. do it. Then, the pixel color output unit 104 stops displaying the sub-picture while the display stop designation color switching signal is active.

FIG. 8 shows two examples (non-interlaced display and interlaced display) of how the character pattern "A" is decoded from the pixel data (sub-picture data) encoded in the example of FIG. It is for explanation.

The decoder 101 shown in FIG. 11 can be used when decoding compressed data as shown in the upper part of FIG. 8 into non-interlaced display data as shown in the lower left part of FIG.

On the other hand, when decoding compressed data as shown in the upper part of FIG. 8 into interlaced display data as shown in the lower right part of FIG. 8, a line doubler (for example, an odd field) for scanning the same pixel line twice is used. Line # 10 having the same content as line # 1 of the above is re-scanned in the even field; switching in V-SYNC units)
Is required.

When non-interlaced display is performed at the same image display amount as interlaced display, another indubbler (for example, line # 10 having the same content as line # 1 at the lower right of FIG. 8 is continued to line # 1) H-SY
NC unit).

FIG. 12 is a block diagram for explaining an embodiment (interlace specification) of decoder hardware having the function of the line doubler. Decoder 1 of FIG.
01 can also be configured by the decoder having the configuration of FIG.

In the configuration of FIG. 12, the microcomputer 112 detects the generation timing of the odd field and the even field of the interlaced display based on the horizontal / vertical synchronization signals of the sub-picture.

When the odd field is detected, the microcomputer 112 supplies the selection signal generator 118 with a mode signal indicating "currently an odd field". Then, a signal for selecting the decoded data from the decoder 101 is output from the selection signal generation unit 118 to the selector 115. Then, lines # 1 to # of the odd field
9 (see the lower right part of FIG. 8)
1 is transmitted to the outside as a video output through the selector 115. At this time, the pixel data of the lines # 1 to # 9 of the odd field are temporarily stored in the line memory 11.
4 is stored.

When the microcomputer 112 detects that it has moved to the even field, the microcomputer 112
8 is supplied with a mode signal indicating "currently an even field". Then, a signal for selecting the data stored in the line memory 114 is output from the selection signal generation unit 118 to the selector 115. Then, the pixel data of the lines # 10 to # 18 of the even field (see the lower right part of FIG. 8)
From the line memory 114 via the selector 115,
It is sent out as a video output.

Thus, the odd-numbered field lines # 1 to # 1
The # 9 sub-picture image (character "A" in the example of FIG. 8) and the sub-picture images of lines # 10 to # 18 of the even-numbered field (FIG.
And the character "A") is synthesized to realize an interlaced display.

By the way, the sub-picture unit header 31 of the sub-picture data shown in FIG. 4 is provided with parameter bits (SPMOD) indicating the frame display mode / field display mode of the TV screen.

When non-interlaced display is performed with the same image display amount as interlaced display, for example, the following is performed.

The microcomputer 112 shown in FIG.
When the sub-picture unit header 31 is read, from the set value of the parameter SPMOD (active = “1”; inactive = “0”), it is determined whether the mode is the interlace mode (active “1”) or the non-interlace mode ( Inactivity "0") can be determined.

In the configuration shown in FIG.
If OD is active = “1”, the microcomputer 112 detects the interlace mode and sends a mode signal indicating the interlace mode to the selection signal generation unit 118. Generation unit 1 receiving this mode signal
Reference numeral 18 gives a switching signal to the selector 115 every time the horizontal synchronization signal H-SYNC is generated. Then, the selector 115
Switches between the decoded output of the current field (DECODED DATA) from the sub-picture decoder 101 and the decoded output of the current field temporarily stored in the line memory 114 every time the horizontal synchronization signal H-SYNC is generated. The video output is sent to an external TV or the like.

As described above, the current decode data and the decode data in line memory 114 are H-SY
When the output is switched for each NC, a video having twice the density (twice the horizontal scanning lines) of the original image (decoded data) is displayed on the TV screen in the interlace mode.

In the sub-picture decoder 101 having such a configuration, instead of reading data for one line and decoding the data, the sequentially input bit data is counted one bit at a time from the beginning of the decoded data unit block. 2 to 16 bits are read and decoded. In this case, the bit length of one unit of decoded data (4 bits, 8 bits, 12 bits, 16 bits, etc.)
Is detected immediately before decoding. Then, in units of the detected data length, the compressed pixel data is restored (reproduced) in real time to, for example, three types of pixels (“•”, “o”, “#” in the example of FIG. 7). go.

For example, when decoding pixel data encoded in accordance with rules 1 to 6 in FIG. 5, sub-picture decoder 101 has a bit counter and a relatively small-capacity data buffer (such as line memory 114). I just need. In other words, the sub-picture decoder 101
Can be made relatively simple, and the whole device including this encoder can be downsized.

That is, the encoder of the present invention does not require a large code table in the decoder unlike the conventional MH coding method, and does not need to read data twice at the time of encoding unlike the arithmetic coding method. . further,
The decoder of the present invention does not require relatively complicated hardware such as a multiplier, and can be implemented by adding simple circuits such as a counter and a small-capacity buffer.

According to the present invention, run-length compression / compression of various types of pixel data (up to four types in a 2-bit configuration) is performed.
Encoding and its run-length decompression / decoding,
This can be realized with a relatively simple configuration.

FIG. 13 is a flowchart for executing image encoding (run-length compression) according to an embodiment of the present invention, and for explaining software executed by, for example, the encoder (200) in FIG. is there.

A series of encoding processes based on the run-length compression rules 1 to 6 in FIG.
It is executed as a software process by a microcomputer in the 00. The entire encoding process by the encoder 200 can be performed according to the flow of FIG. 13, and the run-length compression of the pixel data in the sub-picture data can be performed according to the flow of FIG.

In this case, the computer inside encoder 200 first specifies the number of lines and the number of dots of image data by key input or the like (step ST80).
1), a header area for sub-picture data is prepared, and the line count is initialized to "0" (step ST802).

When the pixel patterns are sequentially input one pixel at a time, the computer inside the encoder 200 acquires the pixel data (here, 2 bits) for the first pixel, saves the pixel data, and saves the pixel data. Count "1"
And the dot count is set to "1" (step ST803).

Subsequently, the internal computer of encoder 200 acquires the pixel data (2 bits) of the next pixel pattern, and compares it with the previously stored pixel data that was input immediately before (step ST804).

As a result of the comparison, if the pixel data are not equal (No in step ST805), encoding conversion processing 1 is performed (step ST806), and the current pixel data is stored (step ST807). Then, the pixel count is incremented by +1 and the dot count is also incremented by +1 (step ST808).

When the pixel data is equal as a result of the comparison in step ST804 (YES in step ST805), the encoding conversion process 1 in step ST806 is skipped and the process proceeds to step ST808.

After incrementing the pixel count and the dot count (step ST808), the internal computer of encoder 200 checks whether or not the pixel line currently being encoded is at the end (step ST809). If it is a line end (step ST8)
09, Yes), the encoding conversion process 2 is performed (step ST810). If it is not the line end (NO in step ST809), the process returns to step ST804, and the processes in steps ST804 to ST808 are repeated.

When the encode conversion process 2 in step ST810 is completed, the computer inside the encoder 200
It is checked whether or not the encoded bit string is an integral multiple of 8 bits (in a byte-aligned state) (step ST811A). If it is not byte-aligned (NO in step ST811A), 4-bit dummy data (0000) is added to the end of the encoded bit string (step ST811B). If the bit string after the dummy addition processing or the encoded bit string is byte-aligned (Yes in step ST811A), the line counter of the computer in the encoder (such as a general-purpose register in the microcomputer) is incremented by +1 (step ST812).

If the last line has not been reached after the line counter has been incremented (NO in step ST813), the flow returns to step ST803, and step ST803 is executed.
To Step ST812 are repeated.

If the last line has been reached after the increment of the line counter (YES in step ST813), the encoding process (run-length compression of the bit string of 2-bit pixel data in this case) ends.

FIG. 14 shows the encoding conversion processing 1 of FIG.
6 is a flowchart for explaining an example of the content of the above.

In the encoding conversion process 1 (step ST806) of FIG. 13, since it is assumed that the pixel data to be encoded has a 2-bit width, the run-length compression rules 1 to 6 of FIG. 5 are applied.

According to these rules 1 to 6, whether the pixel count is 0 (step ST901), the pixel count is 1 to 3 (step ST902), or the pixel count is 4 to 15 (step ST902). Step ST903) or the pixel count number is 16 to 63 (step ST90).
4), whether the pixel count is 64 to 255 (step ST905), whether the pixel count indicates line end (step ST906), or whether the pixel count is 256 or more (step ST907). The determination is made by computer software.

The internal computer of the encoder 200
Based on the above determination result, the number of bits of the run field (one unit length of the same type of pixel data) is determined (steps ST908 to ST913), and after the sub-picture unit header 31, the area corresponding to the number of runfield bits is determined. To secure. The number of continuous pixels is output to the run field secured in this way, the pixel data is output to the pixel field, and a storage device (not shown) inside the encoder 200
(Step ST914).

FIG. 15 is a flowchart for executing image decoding (run-length decompression) according to an embodiment of the present invention. For example, FIG. 11 or FIG. 12 is a flowchart for explaining software executed by the microcomputer 112. It is.

FIG. 16 is a flowchart for explaining an example of the contents of the decoding step (ST1005) used in the software shown in FIG.

That is, the microcomputer 112
Reads the first header 31 of the run-length-compressed sub-picture data (pixel data is composed of 2 bits) and analyzes the contents (see FIG. 4). Then, the number of lines and the number of dots of the data to be decoded are designated based on the analyzed contents of the header. When the number of lines and the number of dots are designated (step ST1)
001), the line count number and the dot count number are initialized to “0” (steps ST1002 to ST1003).

The microcomputer 112 sequentially takes in the data bit string following the sub-picture unit header 31 and counts the number of dots and the number of dot counts. Then, the number of dots is subtracted from the number of dots to calculate the number of continuous pixels (step ST1004).

When the number of continuous pixels is calculated in this manner, microcomputer 112 executes a decoding process according to the value of the number of continuous pixels (step ST1005).

After the decoding processing in step ST1005,
The microcomputer 112 adds the dot count number and the continuous pixel number, and sets this as a new dot count number (step ST1006).

Then, the microcomputer 112 sequentially fetches the data and executes the decoding process in step ST1005. The decoding process for the data is ended (Yes in step ST1007).

Next, if the decoded data is byte-aligned (YES in step ST1008A), the dummy data is removed (step ST1008B).
Then, the line count number is incremented by +1 (step ST1009), and the processing of steps ST1002 to ST1009 is repeated until the last line is reached (No in step ST1010). If the last line has been reached (step ST1010: YES), decoding ends.

Decoding processing step ST100 in FIG.
The processing content of No. 5 is, for example, as shown in FIG.

In this process, after two bits are obtained from the beginning, weaving for determining whether the bit is "0" is repeated (steps ST1101 to ST110).
9). Thereby, the run length compression rules 1 to 6 in FIG.
Are determined (step ST1110 to step ST1113).

After the number of consecutive runs is determined, two bits subsequently read are used as a pixel pattern (pixel data; pixel color information) (step ST111).
4).

When pixel data (pixel color information) is determined,
The index parameter “i” is set to 0 (step ST
1115) Until the parameter “i” matches the continuous run number (step ST1116), the 2-bit pixel pattern is output (step ST1117), and the parameter “i” is incremented by +1 (step ST111).
8) After the output of one unit of the same pixel data is completed, the decoding process ends.

As described above, according to the decoding method of the sub-picture data, the decoding processing of the sub-picture data is a simple process of only a judgment process of several bits, a process of separating data blocks, and a process of counting data bits. I'm done. For this reason, a large code table used in the conventional MH encoding method or the like is not required, and the processing and configuration for decoding the encoded bit data into the original pixel information is simplified.

In the above embodiment, the code bit length for one unit of the same pixel can be determined by reading up to 16 bits of bit data at the time of data decoding. However, the code bit length is not limited to this. Not done. For example, the code bit length may be 32 bits or 64 bits. However, as the bit length increases, a data buffer having a larger capacity is required.

In the above embodiment, the pixel data (color information of the pixel) is, for example, color information of three colors selected from a color palette of 16 colors.
Primary colors (red component R, green component G, blue component B; or luminance signal component Y, chroma red signal component Cr, chroma blue signal component Cb
Etc.) Each amplitude information can be represented by 2-bit pixel data. That is, the pixel data is not limited to a specific type of color information.

FIG. 17 shows a modification of FIG. FIG.
In FIG. 17, the microcomputer 112 performs the operation of cutting out the encoded header by software, but in FIG. 17, the operation of cutting out the encoded header is performed by hardware inside the decoder 101.

That is, as shown in FIG. 17, the run-length-compressed sub-picture data SPD is the data I / O1
02 is sent to the bus inside the decoder 101. The data SPD sent to the bus is sent to the memory 108 via the memory control unit 105, where it is stored. The internal bus of the decoder 101 is connected to the code data separating unit 103, the continuous code length detecting unit 106, and the header extracting unit 113 connected to the microcomputer (MPU or CPU) 112.

The sub-picture unit header 31 of the sub-picture data read from the memory 108
Is read by The cutout unit 113 sends the decoding start address (SPDD) to the address control unit 109 based on the various parameters shown in FIG.
ADR) is set, and information (SPDSIZ) of the display start position, the display width, and the display height of the sub-image is set in the display valid
E) is set, and the display width (the number of dots on a line) of the sub-picture is set in the code data separating unit 103. The set various information is stored in an internal register of each unit (109, 110, 103). Thereafter, the various information stored in the register can be accessed by the microcomputer 112.

The address control unit 109 accesses the memory 108 via the memory control unit 105 based on the decode start address (SPDDDR) set in the register, and starts reading sub-picture data to be decoded. The sub-picture data thus read from the memory 108 is supplied to the code data cutout unit 103 and the continuous code length detection unit 106.

[0204] Run-length compressed sub-picture data SP
The coded header of D (2 to 14 bits in rules 2 to 5 in FIG. 5) is detected by the continuation code length detection unit 106, and the number of continuation pixels of the same pixel data in the data SPD is determined by the continuation code length detection unit 106. Run length setting unit 1 based on signal
07.

Hereinafter, a decoding method different from the decoding method described with reference to FIGS. 15 and 16 will be described with reference to FIGS.

FIG. 18 is a flowchart for explaining the first half of the image decoding (run-length decompression) process according to another embodiment of the present invention.

When decoding is started, each block in the decoder 101 in FIG. 17 is initialized (clearing a register, resetting a counter, etc.). Thereafter, the sub-picture unit header 31 is read, and its contents (various parameters in FIG. 4) are set in the internal register of the header separation unit 113 (step ST1200).

The header 3 is stored in the register of the header separating unit 113.
When the various parameters 1 are set, the microcomputer 112 is notified of the status in which the reading of the header 31 has been completed (step ST1201).

Upon receiving the header reading end status, the microcomputer 112 specifies a decoding start line (for example, SPLine1 in FIG. 4) and notifies the header separation unit 113 of the start line (step ST12).
02).

Upon receiving the notification of the designated decoding start line, the header separating section 113 performs, based on various parameters of the header 31 set in its own register,
The address of the designated decode start line (SP in FIG. 4)
DDADD) and decoding end address (SP in FIG. 4)
EDADR; an address relatively shifted by one line from the start line address) is set in the address control unit 109, and the display start position, display width and display height of the decoded sub-picture and SPDSIZE in FIG. 4 is set in the permission unit 110 and the value of the display width (LNEPIX; FIG.
Although not shown, the number of pixels for one line included in SPDSIZE) is set in the code data separating unit 103 (step ST1203).

[0211] The address control unit 109 sends the decode address to the memory control unit 105. Then, the data to be decoded (compressed sub-picture data SPD)
The encoded data separation unit 103 and the continuation code length detection unit 106 are transferred from the memory 108 via the memory control unit 105.
Is read out. At this time, the read data is set in the internal register of each of the dividing unit 103 and the detecting unit 106 in byte units (step ST120).
4).

The continuation code length detection unit 106
8, the number of “0” bits of the data read out is counted, and from the count value, an encoded header corresponding to one of rules 1 to 5 in FIG. 5 is detected (step S).
T1205). Details of this encoding header detection are shown in FIG.
It will be described later with reference to FIG.

[0213] The continuation code length detection unit 106 determines the segment information SEP.5 corresponding to any one of the rules 1 to 5 in FIG. 5 according to the value of the detected coded header. INFO. Is generated (step ST1206).

For example, if the count value of the “0” bit of the data read from the memory 108 is zero, the segment information SEP. INFO. Is generated, and if the count value is 2, the segment information SEP. IN
FO. Is generated, and if the count value is 4, the segment information SEP. INFO. Is generated, and if the count value is 6, the segment information SEP. INFO.
Is generated, and if the count value is 14, the segment information SEP. INFO. Is generated. The segment information SEP. INFO. Is transferred to the encoded data separation unit 103.

[0215] The coded data separation unit 103 receives the separation information SEP. INFO. Is set in the run length setting unit 107 according to the content of (2), and the 2-bit pixel data (pixel color data; sub-picture data packet) following the continuous pixel number data is set. Data) is set in the pixel color output unit 104. At this time,
Inside the dividing unit 103, the current count value NOWPIX of the pixel counter (not shown) is equal to the continuous pixel number PIXCNT.
(Step ST120).
7).

FIG. 19 shows the second half (FIG. 18) of the image decoding (run-length decompression) process according to another embodiment of the present invention.
9 is a flowchart for explaining the operation after the node A).

In the preceding step ST1203, the encoded data separating section 103 receives the
The number of pixel data (number of dots) LNEPIX for one line corresponding to the display width of the sub-picture is notified. In the encoded data separation unit 103, the value NO of the internal pixel counter
Number of pixel data LNEP for one line notified of WPIX
It is checked whether IX has been exceeded (step ST1208).

In this step, the pixel counter value N
When OWPIX is equal to or greater than the pixel data number LNEPIX for one line (No in step ST1208), 1
The internal register of the separating unit 103 in which the data for the byte has been set is cleared, and the pixel counter value NOWPIX is cleared.
Becomes zero (step ST1209). At this time, if the data is byte-aligned, 4-bit data is truncated. Pixel counter value NOWPI
When X is smaller than the number of pixel data LNEPIX for one line (YES in step ST1208), the dividing unit 103
Is not cleared and remains as it is.

The run length setting section 107 sets the preceding step ST
The number of continuous pixels PIXCNT (run information) set in 1207, the dot clock DOTCLK for determining the transfer rate of the pixel dots, the horizontal and vertical synchronization signals H-SYNC and V-SYNC for synchronizing the sub-picture with the main picture display screen Thus, a display period signal (PERIOD SIGNAL) for outputting the pixel data set in the pixel color output unit 104 for a required period is generated. The generated display period signal is provided to pixel color output section 104 (step ST1210).

The pixel color output unit 104 is provided with the run length setting unit 10
7, while the display period signal is being given, the segment data (eg, pixel data indicating the pixel color) set in the preceding step ST1207 is output as decoded sub-video display data (step ST121).
1).

The sub-picture display data thus output is:
Later, the image is combined with the main video image appropriately in a circuit portion (not shown) and displayed on a TV monitor (not shown).

After the pixel data output process in step ST1211, if the decoded data is not completed, the process returns to step ST1204 in FIG. 18 (No in step ST1212).

Whether the decoded data has been completed depends on whether or not the data up to the end address (SPEDAD) of the sub-picture display data set by the header separating unit 113 has been processed in the encoded data separating unit 103. Can be determined.

When data decoding is completed (step ST1212: YES), it is checked whether or not the display permission signal (DISPLAY ENABLE) from display validity permitting section 110 is active. Display validity permitting unit 11
0 is a data end signal (DA
Until TA END SIGNAL is sent,
An active (for example, high level) display permission signal is generated.

If the display permission signal is active, it is determined that the display period is still in spite of the completion of the data decoding (YES in step ST1213).
In this case, the display validity permitting unit 110 sets the run length setting unit 10
7 and a color switching signal to the pixel color output unit 104 (step ST1214).

At this time, the pixel color output unit 104 has received the missing pixel color data from the missing pixel color setting unit 111. The pixel color output unit 104 that has received the color switching signal from the display validity permitting unit 110 switches the output pixel color data to the insufficient pixel color data from the insufficient pixel color setting unit 111 (step ST1215). Then, while the display permission signal is active (step ST1213 to step ST1)
(Loop 215), during the display period of the sub-picture where there is no decoded data, the display area of the sub-picture is filled with the missing pixel color provided by the missing pixel color setting unit 111.

If the display permission signal is inactive, it is determined that the display period of the decoded sub-picture has ended (No in step ST1213). Then, display validity permitting section 110 transfers an end status indicating that the decoding of one frame of sub-picture has been completed to microcomputer 112 (step ST1216). Thus, the sub-picture decoding process for one screen (one frame) is completed.

FIG. 20 is a flowchart for explaining an example of the contents of the coded header detection step (ST1205) of FIG. This coded header detection process is performed as shown in FIG.
(Or FIG. 11) by the continuation code length detection unit 106
Be executed.

First, the continuation code length detector 106 is initialized, and its internal status counter (STSCNT)
Is set to zero (step ST1301). Thereafter, the contents of the following two bits of the data read from the memory 108 to the detection unit 106 in byte units are checked. If the contents of these two bits are "00" (step ST1302: YES), the counter STSCNT is set to 1
Is incremented by one (step ST1303). If the checked two bits do not reach the end of one byte read by the detection unit 106 (step ST
1304 No), the contents of the subsequent two bits are checked. If the contents of these two bits are "00" (step ST1302: YES), the counter STSCNT is further incremented by one (step ST130).
3).

Steps ST1302 to ST13
As a result of the loop 04 being repeated, step ST1302
If the subsequent two bits checked in step have reached the end of one byte read by the detection unit 106 (YES in step ST1304), the encoded header in FIG. 5 is larger than 6 bits. In this case, the memory 108
, The next data byte is read by the detection unit 106 (step ST1305), and the status counter STSCN is read.
T is set to "4" (step ST1307).
At this time, one byte of the same data is read into the encoded data separation unit 103 at the same time.

When the status counter STSCNT is "4"
, Or in the preceding step ST130
The contents of the two bits checked in 2 are “00”
If not (NO in step ST1302), the contents of the status counter STSCNT are determined, and the contents are
Is output as the contents of the coded header (step ST
1307).

That is, the status counter STSCN
If T = "0", an encoded header indicating rule 1 in FIG. 5 is detected, and if the status counter STSCNT = "1", an encoded header indicating rule 2 in FIG. 5 is detected, and the status counter STSCNT = If "2", an encoded header indicating rule 3 in FIG. 5 is detected, and if the status counter STSCNT = "3", an encoded header indicating rule 4 in FIG. 5 is detected, and the status counter STSC
If NT = “4”, an encoded header indicating rule 5 in FIG. 5 (when the same pixel data continues until the end of the line) is detected.

FIG. 21 is a flowchart for explaining how the image decoding process of the present invention is performed when the decoded image is scrolled.

First, the decoder 10 shown in FIG.
1 are initialized, and a line counter LINCNT (not shown) is cleared to zero (step ST).
1401). Next, the microcomputer 112 (FIG. 1)
1) or the header separation unit 113 (FIG. 17) receives the header reading end status transmitted in step ST1201 of FIG. 18 (step ST1402).

The contents (initially zero) of line counter LINCNT are transferred to microcomputer 112 (FIG. 11) or header separation section 113 (FIG. 17) (step ST1403). The microcomputer 112 or the header separating unit 113 determines that the received status is the end status of one frame (one screen) (step ST12).
06) (step ST14).
04).

If the received status is not the end status of one frame (NO in step ST1405),
Wait for this exit status. If the received status is the end status of one frame (YES in step ST1405), the line counter LINCN
T is incremented by one (step ST140)
6).

The incremented line counter LI
If the content of the NCNT has not reached the end of the line (NO in step ST1407), the decoding processing in FIGS. 15 to 16 or the decoding processing in FIGS. 18 to 19 is restarted (step ST1408), and step ST140 is performed.
Return to 3. This decoding iteration loop (step ST1)
By repeating steps 403 to ST1408), the run-length compressed sub-picture is scrolled while being decoded.

On the other hand, when the incremented content of line counter LINCNT has reached the end of the line (YES in step ST1407), the decoding process of the sub-picture data with scrolling ends.

FIG. 22 is a block diagram illustrating an outline of an optical disk recording / reproducing apparatus in which encoding and decoding are performed according to the present invention.

In FIG. 22, the optical disk player 30
0 is basically a conventional optical disk reproducing device (compact disk player or laser disk player)
It has the same configuration as. However, the optical disc player 300 is configured to decode the run-length-compressed image information from the inserted optical disc OD (recording image information including sub-video data that has been run-length compressed according to the present invention). A digital signal (a digital signal as encoded) can be output. Since this encoded digital signal is compressed, the required transmission bandwidth may be smaller than in the case of transmitting uncompressed data.

[0241] The compressed digital signal from the optical disk player 300 is sent on-air via the modulator / transmitter 210 or sent out to a communication cable.

The compressed digital signal that has been aired or the compressed digital signal that has been transmitted by cable is received by the receiver / demodulator 400 of the receiver or cable subscriber. The receiver 400 includes the decoder 101 having a configuration as shown in FIG. 11 or FIG. The decoder 101 of the receiver 400 decodes the received and demodulated compressed digital signal, and outputs image information including original sub-video data before being encoded.

In the configuration shown in FIG. 22, if the transmission / reception transmission system has an average bit rate of about 5 Mbit / s or more, high-quality multimedia video / audio information can be broadcast.

FIG. 23 is a block diagram illustrating a case where image information encoded according to the present invention is transmitted and received between any two computer users via a communication network (such as the Internet).

User # 1 having self-information # 1 managed by a host computer (not shown) owns personal computer 5001, and this personal computer 5001 has various input / output devices 5011 and various external storage devices 5021. It is connected. An encoder and a decoder according to the present invention are incorporated in an internal slot (not shown) of the personal computer 5001, and a modem card 5031 having a function required for communication is mounted.

Similarly, user # having another self information #N
N owns a personal computer 500N,
Various input / output devices 501N and various external storage devices 502N are connected to the personal computer 500N. In addition, the personal computer 50
An encoder and a decoder according to the present invention are incorporated in an internal slot (not shown) of 0N, and a modem card 503N having a function required for communication is mounted.

Now, a certain user # 1 has a computer 50
It is assumed that the user operates No. 01 to communicate with the computer 500N of another user #N via the line 600 such as the Internet. In this case, since both user # 1 and user #N have modem cards 5031 and 503N in which an encoder and a decoder are incorporated, the present invention can efficiently exchange compressed image data in a short time.

FIG. 24 shows an outline of a recording and reproducing apparatus for recording image information encoded according to the present invention on an optical disk OD and decoding the recorded information according to the present invention.

The encoder 200 shown in FIG. 24 performs the same encoding processing as the encoder 200 shown in FIG.
4) is executed by software or hardware (including firmware or a wired logic circuit).

The recording signal including the sub-picture data and the like encoded by the encoder 200 is subjected to, for example, (2, 7) RLL modulation in the modulator / laser driver 702. The modulated recording signal is sent from the laser driver 702 to the high-power laser diode of the optical head 704. By the recording laser from the optical head 704, a pattern corresponding to the recording signal is written on the magneto-optical recording disk or the phase-change optical disk OD.

The information written on the disk OD is read by the laser pickup of the optical head 706, demodulated by the demodulator / error correction unit 708, and subjected to error correction processing as needed. The demodulated and error-corrected signal undergoes various data processing in the audio / video data processing unit 710, and the information before recording is reproduced.

The data processing section 710 includes a decoding processing section corresponding to the decoder 101 in FIG. The decoding unit (decompression of the compressed sub-picture data) corresponding to FIGS. 15 and 16 is executed by the decoding processing unit.

FIG. 25 exemplifies a state in which an encoder according to the present invention is integrated into an IC together with its peripheral circuits.

FIG. 26 exemplifies a state in which the decoder according to the present invention is integrated into an IC together with its peripheral circuits.

FIG. 27 exemplifies a state in which an encoder and a decoder according to the present invention are integrated with their peripheral circuits in an IC.

That is, the encoder or decoder according to the present invention can be integrated with necessary peripheral circuits into an IC, and this IC can be incorporated in various devices to implement the present invention.

The data line on which the bit string of the compressed data (PXD) as illustrated in FIG. 9 is normally configured to include image information for one horizontal scanning line of the TV display screen. . However, this data line may be configured to include image information for a plurality of horizontal scanning lines on the TV screen, or may be configured to include image information for all horizontal scanning lines for one TV screen (that is, one frame). It can also be configured to include.

The object of data encoding based on the compression rule of the present invention is the sub-picture data (3 to 3) used in the description.
(Color information of four colors). The pixel data portion constituting the sub-picture data may be multi-bit, and various information may be packed therein. For example, if the pixel data is composed of 8 bits per pixel, 256 color images (in addition to the main image) can be transmitted using only the sub image.

[0259]

As described above, according to the present invention, instead of reading data for one line and then performing decoding processing, each time data is taken in bit by bit, the structure of the bit data is compressed by a plurality of compression methods. Data is decoded in small units according to the rules. Therefore, according to the present invention, it is not necessary to have a large code table in the decoder unlike the MH coding method. Further, it is not necessary to read the data twice at the time of encoding unlike the arithmetic coding method. Furthermore, the decoder only needs to have a simple counter for counting bit data, and does not require a multiplier such as an arithmetic coding method for decoding. Therefore, according to the present invention, the decoding process is relatively simple.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a recording data structure of an optical disc as an example of an information storage medium to which the present invention can be applied.

FIG. 2 is a view exemplifying a logical structure of data recorded on the optical disc of FIG. 1;

FIG. 3 is a diagram illustrating a logical structure of a sub-picture pack to be encoded (run-length compressed) in the data structure illustrated in FIG. 2;

4 is a diagram exemplifying the contents of a sub-picture data portion of the sub-picture pack exemplified in FIG. 3, to which an encoding method according to an embodiment of the present invention is applied;

FIG. 5 is a diagram illustrating a compression method employed in an encoding method according to an embodiment of the present invention when pixel data constituting a sub-picture data portion illustrated in FIG. 4 is composed of a plurality of bits (here, 2 bits); The figure explaining rules 1-6.

FIG. 6 illustrates compression rules 11 to 15 employed in an encoding method according to another embodiment of the present invention when pixel data forming a sub-picture data portion illustrated in FIG. 4 is formed of one bit. Figure to do.

FIG. 7 is a diagram showing an example in which pixel data constituting the sub-picture data portion illustrated in FIG. 4 is composed of, for example, first to ninth lines, and a 2-bit pixel (up to four types) is arranged on each line; When character patterns “A” and “B” are represented by 2-bit pixels on each line, how the pixel data of each line is encoded (run-length compressed) will be specifically described. FIG.

FIG. 8 is a view for explaining two examples (non-interlaced display and interlaced display) of how the character pattern “A” is decoded from the pixel data (sub-picture data) encoded in the example of FIG. 7; .

FIG. 9 specifically shows compression rules 1 to 6 used in the encoding method according to the embodiment of the present invention when the pixel data forming the sub-picture data portion illustrated in FIG. 4 is composed of 2 bits. FIG.

FIG. 10 explains the flow from mass production to reproduction on the user side of a high-density optical disk having image information encoded according to the present invention; from broadcasting / cable distribution of image information encoded according to the present invention; FIG. 3 is a block diagram illustrating a flow up to reception / reproduction by a user / subscriber.

FIG. 11 is a block diagram illustrating an embodiment (non-interlaced specification) of decoder hardware that executes image decoding (run-length expansion) based on the present invention.

FIG. 12 is a block diagram illustrating another embodiment (interlace specification) of decoder hardware that executes image decoding (run-length expansion) based on the present invention.

FIG. 13 is a flowchart illustrating software that executes image encoding (run-length compression) according to the embodiment of the present invention and is executed by, for example, the encoder (200) in FIG. 10;

FIG. 14 is a flowchart illustrating an example of the contents of an encoding step 1 (ST806) used in the software of FIG. 13;

FIG. 15 is a flowchart for explaining software executed by the MPU (112) of FIG. 11 or 12 for executing image decoding (run-length decompression) according to an embodiment of the present invention; .

16 is a flowchart illustrating an example of the contents of a decoding step (ST1005) used in the software of FIG.

FIG. 17 is a block diagram illustrating another embodiment of decoder hardware that executes image decoding (run-length expansion) based on the present invention.

FIG. 18 is a flowchart illustrating the first half of an image decoding (run-length decompression) process according to another embodiment of the present invention.

FIG. 19 is a flowchart for explaining the latter half of the image decoding (run-length extension) process according to another embodiment of the present invention.

FIG. 20 shows an encoded header detection step (ST1) in FIG.
FIG. 205 is a flowchart for explaining an example of the contents of 205).

FIG. 21 is a flowchart for explaining how the image decoding process of the present invention is performed when the decoded image is scrolled.

FIG. 22 is a diagram illustrating a compressed data reproduced from a high-density optical disk having image information encoded according to the present invention, which is broadcast or cable-distributed, and the broadcast or cable-distributed compressed data is decoded by a user or a subscriber; FIG. 4 is a block diagram illustrating a case.

FIG. 23 is a block diagram illustrating a case where image information encoded according to the present invention is transmitted and received between any two computer users via a communication network (such as the Internet).

FIG. 24 is a block diagram illustrating an outline of an optical disc recording / reproducing apparatus on which encoding and decoding are performed according to the present invention.

FIG. 25 is a diagram exemplifying a state where the encoder based on the present invention is formed into an IC.

FIG. 26 is a diagram exemplifying a state where the decoder based on the present invention is formed into an IC.

FIG. 27 is a diagram illustrating a state where an encoder and a decoder according to the present invention are integrated into an IC;

[Explanation of symbols]

30 ... Compressed sub-picture data unit (SPU); 3
1 ... sub-picture unit header (SPUH); 32 ... compressed sub-picture pixel data (PXD); 101 ... decoder;
102: data I / O; 103: coded data separation part;
104: Pixel color output unit (FIFO type); 105: Memory control unit; 106: Continuous code length detection unit; 107: Run length setting unit; 108: Memory; 109: Address control unit; ... Insufficient pixel color setting unit; 112... Microcomputer (MPU or CP)
U); 113: header segment; 114: line memory;
115 selector; 118 select signal generator; 20
0: encoder; 202: laser cutting device; 2
04: optical disk master; 206: mass production equipment for two-layer high-density optical disk; 202 to 206: recording device; 210
... modulator / transmitter; 212 ... broadcast unit / cable output unit;
300: disk player (reproducing device); 400: receiver / demodulator (reproducing device); 5001 (500N): personal computer; 5011 (501N): input / output devices; 5021 (502N): external storage devices;
1 (503N) ... encoder / decoder and modem;
702: modulator / laser driver; 704: optical head (recording laser); 706: optical head (reading laser / laser pickup); 708: demodulator / error correction unit;
10: audio / video data processing unit (including decoding processing unit for sub-picture data); OD: two-layer bonded high-density optical disk (recording medium).

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04N 9/808 H04N 9/80 B 11/04 (72) Inventor Kazuhiko Taira 3-3-9 Shimbashi, Minato-ku, Tokyo TOSHIBA A-V・ Inside E Co., Ltd. (72) Inventor Tetsuya Kitamura 70, Yanagicho, Saiwai-ku, Kawasaki-shi, Kanagawa Pref.

Claims (20)

[Claims] 1. An image information recording apparatus which records information obtained by compressing a data block in which the same pixel data continues as one compression unit in an information aggregate formed by collecting a plurality of pixel data defined by a plurality of bits. (B) an encoding header corresponding to the number of continuous same pixel data in the data block of one compression unit, continuous pixel number data indicating the same number of continuous pixel data; An encoding step of encoding information of a compression unit data block constituted by data of a plurality of bits indicating the same pixel data itself in the data block; and (b) a medium master on which the information encoded in the encoding step is written. (C) using the media master created in the master creation step. Te, the information encoded in the encoding step,
A method for producing a medium for recording on at least one image information recording medium. 2. If the data length of the same pixel data continuation number in the data block of one compression unit is 3 or less, no bit is assigned to the encoding header, and the same pixel in the data block of one compression unit is used. 2. The method according to claim 1, wherein when the data length of the continuous data number is 4 or more and a predetermined number or less, 2 bits or more and a predetermined bit or less are assigned to the encoded header. 3. 3. When the information aggregate is arranged on a data line having a finite bit length, and the same pixel data in the data block of one compression unit continues to the line end of the data line, The method according to claim 1, wherein the encoded header is configured with a specific number of bits indicating that pixel data continues to the line end. 4. When the information aggregate is arranged on a data line having a finite bit length, and the same pixel data in the data block of one compression unit continues up to the line end of the data line, The encoded header is configured with a specific number of bits indicating that the pixel data continues to the line end; when the same pixel data in the data block of one compression unit is not continuous to the line end of the data line, If the data length of the same pixel data continuation number in the data block of one compression unit is 3 or less, no bit is allocated to the encoded header, and the data length of the same pixel data continuation number in the data block of one compression unit is Is greater than or equal to 4 and less than or equal to a predetermined number, two or more and less than or equal to a predetermined number of bits are assigned to the encoded header. The method according to claim 1, wherein the method is applied. 5. When the information aggregate is arranged on a data line having a finite bit length, when the generation of a compression unit data block for all data on the data line is completed, the entire compression unit data block is generated. 2. The manufacturing method according to claim 1, wherein, if the bit length is not an integral multiple of 8 bits, dummy bit data whose total bit length is an integral multiple of 8 bits is added. 6. If the data length of the same pixel data continuation number in the data block of one compression unit is 3 or less, no bit is assigned to the encoding header, and the same pixel data continuation in the data block of one compression unit is not performed. When the data length of the number is 4 or more and a predetermined number or less, two bits or more and a predetermined bit or less are assigned to the encoded header, and when the information aggregate is arranged on a data line having a finite bit length, If the bit length of the entire compression unit data block is not an integral multiple of 8 bits when the generation of the compression unit data block for all data on this data line is completed, the total bit length is set to an integral multiple of 8 bits. 2. The method according to claim 1, wherein dummy bit data is added. 7. When the information aggregate is arranged on a data line having a finite bit length, and the same pixel data in the data block of one compression unit continues up to the line end of the data line, The encoding header is configured with a specific number of bits indicating that the pixel data continues to the line end; when the information aggregate is arranged on a data line having a finite bit length, If the bit length of the entire compressed unit data block is not an integral multiple of 8 bits when the generation of the compressed unit data block for all data is completed, dummy bit data whose integral bit length is an integral multiple of 8 bits. The method according to claim 1, wherein is added. 8. When the information aggregate is arranged on a data line having a finite bit length, and the same pixel data in the data block of one compression unit continues up to the line end of the data line, The encoding header is configured with a specific number of bits indicating that the pixel data continues to the line end; when the information aggregate is arranged on a data line having a finite bit length, If the bit length of the entire compressed unit data block is not an integral multiple of 8 bits when the generation of the compressed unit data block for all data is completed, dummy bit data whose integral bit length is an integral multiple of 8 bits. 3. The method according to claim 2, further comprising: 9. The method according to claim 1, wherein the encoding step includes a step of compressing a moving image based on the MPEG standard, and the moving image compressed based on the MPEG standard is written to the medium master. Any one of
The production method according to the paragraph. 10. The image information recording medium has a standard thickness of 1.2 mm obtained by laminating a substrate having a substantial thickness of 0.6 mm.
The method according to any one of claims 1 to 9, wherein information recorded on the medium master is transferred to at least one of the bonded substrates. Optical disc created with. 11. An information aggregate formed by gathering a plurality of pixel data defined by a plurality of bits, and information obtained by compressing a data block in which the same pixel data is continuous as one compression unit in a predetermined pack unit. An image information recording medium having a recording track which is packetized and recorded as a data packet, comprising: a data block of one compression unit; an encoding header corresponding to the number of consecutive same pixel data in the data block; And data of a plurality of bits indicating the same pixel data itself in the data block of the one compression unit; and forming predetermined compressed data including one or more of the data blocks; A predetermined header is added to the compressed data to constitute one unit of the compressed data; Serial data packet, the corresponding sequences as one unit of the compressed data, the record information recording medium characterized in that it is recorded in the track. 12. When the data length of the same pixel data continuation number in the data block of one compression unit is 3 or less, no bit is assigned to the encoded header, and the same pixel in the data block of one compression unit is used. 12. The information recording medium according to claim 11, wherein when the data length of the continuous data number is 4 or more and a predetermined number or less, 2 bits or more and a predetermined bit or less are assigned to the encoded header. 13. When the information aggregate is arranged on a data line having a finite bit length and the same pixel data in the data block of one compression unit continues to the line end of the data line, 13. The information recording medium according to claim 11, wherein the encoded header is configured with a specific number of bits indicating that pixel data continues to the line end. 14. When the information aggregate is arranged on a data line having a finite bit length, when the generation of a compression unit data block for all data on this data line is completed, the entire compression unit data block is generated. 14. If the bit length is not an integral multiple of 8 bits, dummy bit data whose total bit length is an integral multiple of 8 bits is added. The information recording medium described in the section. 15. The information recording medium has a substantial thickness of 0.6.
An optical disc having a standard thickness of 1.2 mm, which is obtained by laminating substrates having a thickness of 1.2 mm, is characterized in that at least one unit of the compressed data is transferred to one or both of the laminated substrates. An information recording medium according to any one of claims 11 to 14. 16. An information set formed by gathering a plurality of pixel data defined by a plurality of bits, and information obtained by compressing a data block in which the same pixel data is continuous as one compression unit, in a predetermined pack unit. An optical disk having a recording track for packetizing and recording as a data packet, wherein the compressed information can be reproduced in the pack unit by a reproducing apparatus having an optical head, wherein the data block in one compression unit is the data block. , A coded header corresponding to the number of consecutive identical pixel data, continuous pixel number data indicating the consecutive number of identical pixel data, and data of a plurality of bits indicating the same pixel data itself in the data block of one compression unit. A predetermined compressed data including one or more of the data blocks. ; With a predetermined header to the post-compression data, one unit of the compressed data is configured;
One or more of the data packets are recorded on the recording track in an array corresponding to one unit of the compressed data; when the playback device plays back the compressed information, the array of one or more of the data packets is: An optical disc recorded on the recording track so that it can be continuously reproduced by the optical head. 17. If the data length of the same pixel data continuation number in the data block of one compression unit is 3 or less, no bit is assigned to the encoded header, and the same pixel in the data block of one compression unit is used. 17. The optical disk according to claim 16, wherein when the data length of the continuous data number is 4 or more and a predetermined number or less, 2 bits or more and a predetermined bit or less are assigned to the encoded header. 18. The information aggregate is arranged on a data line having a finite bit length, and when the same pixel data in the data block of one compression unit continues up to the line end of the data line, the same 18. The optical disc according to claim 16, wherein the encoded header is configured with a specific number of bits indicating that pixel data continues to the line end. 19. When the information aggregate is arranged on a data line having a finite bit length, when the generation of a compression unit data block for all data on this data line is completed, the entire compression unit data block is 19. The dummy bit data whose total bit length is an integral multiple of 8 bits is added when the bit length of the data is not an integral multiple of 8 bits. An optical disk according to the item. 20. The information recording medium having a substantial thickness of 0.6
An optical disc having a standard thickness of 1.2 mm, which is obtained by laminating substrates having a thickness of 1.2 mm, is characterized in that at least one unit of the compressed data is transferred to one or both of the laminated substrates. An optical disc according to any one of claims 16 to 19.