JP3990119B2 - Information encoding apparatus, method thereof, program thereof and recording medium on which program is recorded, and information reproducing apparatus, method thereof, program thereof and recording medium on which program is recorded - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information encoding device used for optical information recording, a method thereof, a program thereof, a recording medium on which the program is recorded, an information reproducing device used for optical information reproduction, a method thereof, Regarding the program.
[0002]
[Prior art]
In a holographic memory or the like, information to be recorded is first two-dimensionally encoded and recorded as a black or white pixel on a recording medium (recording material) using laser light or the like as signal light or reference light. Then, a two-dimensional image obtained by the image sensor using laser light or the like as reproduction light is decoded and reproduced to the original information.
[0003]
[Problems to be solved by the invention]
Normally, the recording density of pixels in the recording medium is lower than the reading resolution. According to the sampling theorem, the recording density needs to be 1/3 times or less of the reading resolution.
[0004]
In order to completely restore the original signal with respect to the input signal, a sampling frequency that is twice or more of the maximum frequency is required. First, the minimum unit of reading is the pixel size of a reading device, for example, a CCD camera. That is, the minimum pixel size of the hologram image is the pixel size of the CCD camera. In this case, the sampling theorem is applied as follows.
[0005]
1. When the positional deviation only in the horizontal and vertical directions is allowed between the image and the CCD, the minimum size that can be read by the CCD is 2 × 2 pixels.
[0006]
2. If the positional deviation in the rotation direction is allowed, the minimum size is 3 × 3 pixels. This is because when the image is inclined 45 degrees, the length of the signal is the maximum, and one side of the pixel × √2. Therefore, if it is 2 × 2 pixels, it is about 2. Eight pixels are required, and 3 × 3 pixels are required.
[0007]
That is, 1-bit information must be expressed by a 3 × 3-bit encoded block at a minimum. Furthermore, in a multi-layer holographic memory, the contrast at the time of reading deteriorates due to light noise from other layers, so in reality, the recording density must be further reduced.
[0008]
On the other hand, the amount of information handled in a highly information-oriented society is steadily increasing, and even in holographic memory, there is a desire to reduce the redundancy in recorded images and increase the essential information density. strong. For this purpose, in order to increase the information density while maintaining a low recording density, a new technique must be introduced for two-dimensional encoding of information and reproduction from the read image to the original information. .
[0009]
Accordingly, the present invention has been made in view of the above-described conventional problems, and an object of the present invention is to provide an information code capable of encoding information to be recorded at a two-dimensional and higher information density in optical information recording. And an information reproducing apparatus capable of reproducing a multi-valued image obtained by optical reading after recording by the apparatus into original information.
[0010]
[Means for Solving the Problems]
In order to solve the above-described conventional problems, the present invention according to claim 1 is an information encoding apparatus used for optical information recording.
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. A basic block generating means for generating as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generating means for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding apparatus including an expanded basic block arrangement unit that arranges each of the generated extended basic blocks in a predetermined recording area according to the order of information bits in the input information is used as a solution unit.
[0011]
The present invention according to claim 2 is an information encoding method used for optical information recording.
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding method including an extended basic block arrangement procedure for arranging each of the generated extended basic blocks in a predetermined recording area in accordance with the order of information bits in the input information is used as a solution means.
[0012]
The present invention according to claim 3 is an information encoding program used for optical information recording.
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding program comprising an extended basic block arrangement procedure for arranging each of the generated extended basic blocks in a predetermined recording area in accordance with the order of information bits in the input information is used as a solving means.
[0013]
The present invention according to claim 4 is a recording medium on which an information encoding program used for optical information recording is recorded,
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
A recording medium on which is recorded an information encoding program that includes each of the generated extended basic blocks arranged in a predetermined recording area according to the order of information bits in the input information. Let it be a solution.
[0014]
According to these embodiments of the present invention, 2-bit information can be represented by a 4 × 4-bit encoded block. That is, information can be encoded two-dimensionally with a higher information density. Further, since one bit is not adjacent to each other, erroneous recognition at the time of reading can be prevented. Note that setting the bit to “1” means a meaningful value, and inverting the logic to “0” is also included in the technical scope of the present invention.
[0015]
According to a fifth aspect of the present invention, there is provided an information reproducing apparatus for reproducing information when a recorded pixel is optically read.
Enlarged basic block detection means for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels;
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection means for
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproducing apparatus comprising information reproducing means arranged in accordance with the position of the enlarged basic block in the read image is used as the solving means.
[0016]
According to a sixth aspect of the present invention, there is provided an information reproducing method for reproducing information when recorded pixels are optically read.
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproduction method including an information reproduction procedure arranged according to the position of the enlarged basic block in the read image is used as the solving means.
[0017]
The present invention according to claim 7 is an information reproduction program for reproducing information when a recorded pixel is optically read.
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproduction program comprising an information reproduction procedure arranged according to the position of the enlarged basic block in the read image is used as the solving means.
[0018]
The present invention according to claim 8 is a recording medium on which an information reproduction program for reproducing information when a recorded pixel is optically read is recorded,
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproducing program including an information reproducing procedure arranged in accordance with the position of the enlarged basic block in the read image is used as a solving means.
[0019]
Prior to the implementation of the present invention, an image recorded in units of 4 × 4 bit encoded blocks including 2 bits of information is read to generate a multi-valued image. According to the present invention, this multi-valued image can be reproduced as the original information before being encoded.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of an information recording / reproducing apparatus 1 according to an embodiment of the present invention. The information recording / reproducing apparatus 1 is a computer including a recording unit 100 and a reproducing unit 200 as shown in FIG. The recording unit 100 and the reproducing unit 200 correspond to the information encoding device and the information reproducing device of the present invention, respectively.
[0021]
[First embodiment]
First, the recording unit 100 will be described as a first embodiment. As shown in FIG. 1B, the recording unit 100 includes an input information dividing unit 11, a recording bit string generating unit 12, a basic block generating unit 13, an enlarged basic block generating unit 14, a recorded image generating unit 15, a conversion table TB1, and TB2 is provided. These means are realized by executing a program stored in the information recording / reproducing apparatus 1 in advance. On the other hand, the conversion tables TB1 and TB2 are configured in a main storage device, an external storage device, or the like. The input information dividing unit 11, the recording bit string generating unit 12, and the basic block generating unit 13 constitute a basic block generating unit of the present invention. The enlarged basic block generating unit 14 corresponds to the enlarged basic block generating unit of the present invention. The recorded image generating means 15 corresponds to the enlarged basic block arranging means of the present invention.
[0022]
The input information dividing unit 11 divides the inputted input information D (information in which bits are arranged, that is, sequential bits) every two bits. The 2-bit information obtained by this division is called “information bit”. The recording bit string generation means 12 generates a 4-bit bit string (referred to as information bit string) based on the information bits. The basic block generation unit 13 generates a 2 × 2 bit encoded block (referred to as a basic block) based on the generated information bits. The expanded basic block generation unit 14 generates a 4 × 4 bit encoded block (referred to as an expanded basic block) based on the generated basic block B.
[0023]
In this specification, for convenience, the data stored in the memory is often illustrated two-dimensionally, but the value 1 is shown in black and the value 0 is shown in white. Of course, negative logic may be adopted if such logic is positive logic. Further, in the process of recording and reproducing information, processing may be performed by temporarily inverting the logic, but this situation will not be considered.
[0024]
In the present embodiment, an image recording area is provided in advance according to the amount of information to be recorded, and when the enlarged basic blocks BB are arranged in this area in the horizontal direction, the enlarged basic number is set as the maximum number that can be arranged. The number m of blocks and the maximum number n of enlarged basic blocks when arranged in the vertical direction are preset in the recording unit 100.
[0025]
As shown in FIG. 2, the information bit string is a 4-bit bit string generated based on the information bits, and only one of the bits is set to 1. Further, the information bit string is obtained by changing the position of the bit that is 1 in accordance with the value of the information bit that is the basis. Note that any conversion method shown in FIG. 2 can be adopted, but the conversion method 24 is adopted. That is, the information bit (00) is in the first information bit string (0001), the information bit (01) is in the second information bit string (0010), and the information bit (10) is in the third information bit string (0100). The information bit (11) is converted into the fourth information bit string (1000).
[0026]
As shown in FIG. 3, the basic block B is a coding block in which 2 bits are provided in the vertical direction and 2 bits are provided in the horizontal direction, and only 1 of them is set to 1. In the present embodiment, a total of four types of basic blocks B are used in which each of the upper right, lower left, and lower right is set to 1, in addition to the upper left shown in FIG. When these are distinguished, they are called first, second, third, and fourth basic blocks in order. “Block” may be read as “matrix”.
[0027]
As shown in FIG. 3, the extended basic block BB is a 4 × 4 bit encoded block, and only 1 bit is set to 1. One enlarged basic block BB is generated for one basic block B based on one basic block B. The enlarged basic block BB is positioned at the bit position which is 1 in the basic block among the 2 × 2-bit blocks in the upper left, upper right, lower left and lower right constituting the enlarged basic block BB. In one block at the corresponding position, only the bit at a predetermined position is set to 1.
[0028]
The conversion table TB1 shown in FIG. 4 is used by the basic block generation means 13, and the first information bit string is used as the first basic block, the second information bit string is used as the second basic block, and the third information bit string is used as the third information block. The information bit string is associated with the third basic block, and the fourth information bit string is associated with the fourth basic block.
[0029]
As shown in the method 2 in FIG. 5, the second, third, fourth, and first basic blocks may be associated with the first, second, third, and fourth information bit strings, respectively. , 4 information bit strings may be associated with the third, fourth, and first basic blocks, respectively, and the first, second, third, and fourth information bit strings may be respectively associated with the fourth, first, second, and third basic blocks. May be associated.
[0030]
The conversion table TB2 shown in FIG. 6 is used by the enlarged basic block generation unit 14, and the first basic block is used as the first extended basic block, the second basic block is used as the second extended basic block, The third basic block is associated with the third enlarged basic block, and the fourth basic block is associated with the fourth enlarged basic block.
[0031]
The enlargement method is the same as the enlargement method 1 in FIG. 7, in the basic block that is the base of the upper left, upper right, lower left, and lower right 2 × 2 bit blocks that constitute the enlarged basic block BB. In one block at a position corresponding to the position of a bit that is 1, only the “upper left” bit is set to 1. It should be noted that not only “upper left”, but “upper right” as shown in the enlargement method 2, or “lower left” like the enlargement method 3, or only the “lower right” bit as in the enlargement method 4. May be 1.
[0032]
Next, the operation of the first embodiment will be described. FIG. 8 is a flowchart of processing performed by the recording unit 100. Steps S11, S12 and S13 constitute the basic block generation procedure of the present invention. Step S14 corresponds to the enlarged basic block generation procedure of the present invention. Step S15 corresponds to the enlarged basic block arrangement procedure of the present invention.
[0033]
First, in step S11, the input information division means 11 divides the inputted input information D every two bits. Next, in step S12, the recording bit string generation means 12 generates an information bit string based on the divided information bits. Next, in step S13, the basic block generation means 13 performs conversion table TB1.
, A 2 × 2 bit basic block corresponding to each generated information bit string is generated.
[0034]
Next, in step S14, the enlarged basic block generation unit 14 refers to the conversion table TB2 and generates a 4 × 4 bit extended basic block based on the generated basic block. Next, in step S15, the recorded image generating means 15 generates the recorded image G by arranging the generated enlarged basic blocks by the number m of enlarged basic blocks horizontally and the number n of enlarged basic blocks vertically. At this time, the enlarged basic blocks are arranged in the storage area according to the order of the information bits in the input information. For example, if the enlarged basic block obtained from the first information bit in the input information is arranged at the upper left of the recording area, the one obtained from the next information bit is sequentially arranged to the right, and the number of enlarged basic blocks is arranged for m. A method such as a line feed can be adopted.
[0035]
Therefore, according to the first embodiment, 2-bit information can be represented by a 4 × 4-bit encoded block. That is, information can be encoded two-dimensionally with a higher information density. Further, since one bit is not adjacent to each other, erroneous recognition at the time of reading can be prevented.
[0036]
The recording image G obtained in this way becomes a black and white pixel according to the bit value in the recording image G, for example, on a recording material such as a holographic memory, for example, about 1.8 Mbit / square inch. Recorded in density.
[0037]
[Second Embodiment]
Next, the reproducing unit 200 will be described as a second embodiment.
[0038]
FIG. 9 is a diagram illustrating the configuration of the playback unit 200. The reproducing unit 200 includes an enlarged basic block detecting unit 21, a sub-block detecting unit 22, a recording bit string detecting unit 23, an information bit string converting unit 24, and an information reproducing unit 25. Such means is realized by executing a program stored in the information recording / reproducing apparatus 1 in advance.
[0039]
The enlarged basic block detecting means 21 corresponds to the enlarged basic block detecting means of the present invention. The sub-block detection unit 22 corresponds to the sub-block detection unit 22 of the present invention. The recording bit string detecting means 23, the information bit string converting means 24, and the information reproducing means 25 constitute the information reproducing means of the present invention.
[0040]
Now, the pixels recorded in the holographic memory are sampled by a reading device using a CCD image sensor or the like. At this time, it is assumed that sampling is performed at 1.8 Mbit / in 2 which is the same as the recording density, and quantization is performed with 8 bits (256 gradations).
[0041]
The sampled image (referred to as read image E) is a multivalued image in which pixel values obtained by quantization are arranged vertically and horizontally.
[0042]
As shown in FIG. 10, “deviation” occurs between the reading device and the recorded image. Furthermore, since light may be incident as noise during reading, the pixel value will not be either 255 (white or bright in the figure) or 0 (black or dark in the figure) even if the pixel is either black and white. The read image E includes intermediate pixel values.
[0043]
In the present embodiment, it is assumed that the read image E is composed of a 4 × 4 bit pixel value block (enlarged basic block TT) as a unit of reproduction processing.
[0044]
Furthermore, as shown in FIG. 11, 2 × 2 pixel value blocks (referred to as sub-blocks T) occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block TT are first, second, third, fourth, and fourth. Sub-blocks T1, T2, T3, and T4 are used.
[0045]
The enlarged basic block detecting means 21 detects the enlarged basic block TT. The sub-block detection means 22 detects the sub-block T included in the enlarged basic block TT. The recording bit string detection means 23 detects the information bit string included in the enlarged basic block for each enlarged basic block TT. The information bit string converter 24 converts the information bit string into information bits. The information reproducing means 25 arranges the information bits according to the arrangement of the enlarged basic blocks in the read image.
[0046]
Next, the operation of the second embodiment will be described. FIG. 12 is a flowchart of processing performed by the playback unit 200. Step S21 corresponds to the enlarged basic block detection procedure of the present invention. Step S22 corresponds to the sub-block detection procedure of the present invention. Steps S23, S24 and S25 constitute the information reproduction procedure of the present invention.
[0047]
First, in step S21, the enlarged basic block detecting means 21 detects all enlarged basic blocks TT included in the read image E. In subsequent step S22, the sub-block detecting means 22 detects sub-blocks T1, T2, T3 and T4 in the enlarged basic block TT. Such detection is performed for all of the enlarged basic blocks.
[0048]
In step S23, the recording bit string detection means 23 detects an information bit string from the enlarged basic block. Specifically, first, as shown in Equation (1) in FIG. 13, the sum V ₁ , V ₂ , V ₃ , V ₄ of pixel values for each sub-block is obtained.
[0049]
However, V _n1 , V _n2 , V _n3 , and V _n4 (n = 1, ₂ , ₃ , and 4) are the upper left, upper right, lower left, and lower right pixel values of the nth sub-block, respectively.
[0050]
Next, as shown in Expression (2) of FIG. 14, for example, when the minimum value among V ₁ , V ₂ , V ₃ , and V ₄ is V ₁ , the information bit string is set to 1000. On the other hand, when the minimum values are V ₂ , V ₃ , and V ₄ , the information bit strings are 0100, 0010, and 0001, respectively. If it is negative logic, an information bit string corresponding to the maximum value is obtained. That is, according to the logic, which value is unique among V ₁ , V ₂ , V ₃ and V ₄ (which is particularly different from the other three values) is obtained.
[0051]
Note that the recording bit string detection unit 23 performs this process for all the enlarged basic blocks.
[0052]
Next, in step S24, the information bit string conversion means 24 converts the information bit string into information bits for all information bit strings. That is, the first information bit string (0001) is the information bit (00), the second information bit string (0010) is the information bit (01), the third information bit string (0100) is the information bit (10), The fourth information bit string (1000) is converted into information bits (11), respectively.
[0053]
Next, in step S25, when the information reproducing means 25 takes, for example, the above-described method as an example, the information bit corresponding to the expansion basic block detected on the upper left is sequentially expanded to the basic block detected on the right. The information is reproduced by, for example, following an information bit corresponding to.
[0054]
Therefore, according to the second embodiment, a multi-valued image can be reproduced as input information before encoding and recording, and information is reproduced depending on the total sum of pixels. It becomes difficult to receive. As a result, the encoding described in the first embodiment can be put into practical use.
[0055]
The program for executing the processing described above is recorded on a computer-readable recording medium such as a semiconductor memory, magnetic disk, optical disk, magneto-optical disk, magnetic tape, or transmitted via a communication network such as the Internet. And can be widely distributed.
[0056]
【The invention's effect】
As described above, according to the information encoding of the present invention, information to be recorded can be encoded two-dimensionally and with a higher information density in optical information recording. Further, according to the information reproduction of the present invention, it is possible to reproduce the multi-valued image obtained by the encoding by the information encoding of the present invention and the optical reading after recording into the original information.
[Brief description of the drawings]
FIG. 1 (a) is a diagram showing a configuration of an information recording / reproducing apparatus 1 according to the present invention. FIG. 1B is a diagram illustrating a configuration of the recording unit 100.
FIG. 2 is a diagram illustrating a method of converting information bits into information bit strings.
FIG. 3 is a diagram showing a basic block and an enlarged basic block.
FIG. 4 is a diagram showing a conversion table TB1.
FIG. 5 is a diagram illustrating a method of converting an information bit string.
FIG. 6 is a diagram showing a conversion table TB2.
FIG. 7 is a diagram illustrating a method of enlarging a basic block.
FIG. 8 is a flowchart of processing performed by a recording unit.
9 is a diagram showing a configuration of a playback unit 200. FIG.
FIG. 10 is a diagram illustrating a recorded image and a read image.
FIG. 11 is a diagram showing sub-blocks T1, T2, T3, and T4 in the enlarged basic block TT.
12 is a flowchart of processing performed by the playback unit 200. FIG.
FIG. 13 is a diagram illustrating processing performed by a recording bit string detection unit.
FIG. 14 is a diagram illustrating processing performed by a recording bit string detection unit.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Information recording / reproducing apparatus 11 Input information division | segmentation means 12 Recording bit string generation means 13 Basic block generation means 14 Extended basic block generation means 15 Recorded image generation means 21 Extended basic block detection means 22 Sub-block detection means 23 Recording bit string detection means 24 Information bit string Conversion means 25 Information reproduction means 100 Recording section 200 Playback section B Basic block BB Enlarged basic block D Input information G Recorded image E Read image m, n Number of enlarged basic blocks T, T1, T2, T3, T4 Sub-blocks TB1, TB2 Conversion Table TT Expanded basic block

Claims (8)

In an information encoding device used for optical information recording,
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. A basic block generating means for generating as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generating means for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding apparatus comprising: expanded basic block arrangement means for arranging the generated extended basic blocks in a predetermined recording area in accordance with the order of information bits in the input information. In an information encoding method used for optical information recording,
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding method comprising: an expansion basic block arrangement procedure for arranging each of the generated expansion basic blocks in a predetermined recording area in accordance with the order of information bits in the input information. In an information encoding program used for optical information recording,
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
An information encoding program comprising: an extended basic block arrangement procedure for arranging each of the generated extended basic blocks in a predetermined recording area in accordance with the order of information bits in the input information. A recording medium on which an information encoding program used for optical information recording is recorded,
Input information in which bits are arranged is a 2 × 2 bit encoded block for each information bit, with 2 bits as information bits, and only the bit corresponding to the value of the information bit is set to 1. Generating a basic block as a basic block;
For each of the generated basic blocks, a 4 × 4 bit encoded block and a bit that is 1 in the basic block among the upper left, upper right, lower left, and lower right 2 × 2 bit blocks An enlarged basic block generation procedure for generating, as an enlarged basic block, a block at a position corresponding to a position, in which only a bit at a predetermined position is set to 1.
A recording medium on which is recorded an information encoding program including an expanded basic block arrangement procedure for arranging each of the generated extended basic blocks in a predetermined recording area according to the order of information bits in the input information. In an information reproducing apparatus for reproducing information when recorded pixels are optically read,
Enlarged basic block detection means for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels;
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection means for
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproducing apparatus comprising information reproducing means arranged according to the position of the enlarged basic block in the read image. In an information reproduction method for reproducing information when a recorded pixel is optically read,
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproduction method comprising: an information reproduction procedure arranged according to the position of the enlarged basic block in the read image. In an information reproduction program for reproducing information when recorded pixels are optically read,
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is An information reproduction program comprising: an information reproduction procedure arranged according to the position of the enlarged basic block in the read image. A recording medium on which an information reproduction program for reproducing information when a recorded pixel is optically read is recorded,
An enlarged basic block detection procedure for detecting each enlarged basic block from the read image when the read image in which the read pixel values are arranged vertically and horizontally is composed of an enlarged basic block that is a pixel value block of 4 × 4 pixels,
For each detected enlarged basic block, a 2 × 2 pixel value block occupying each corner of the upper left, upper right, lower left, and lower right of the enlarged basic block is detected as first, second, third, and fourth sub-blocks. Sub-block detection procedure to
A total sum of pixel values included in each sub-block is obtained for each of the detected enlarged basic blocks, and an information bit value is obtained according to which one of the obtained sums is unique, and the information bit is A recording medium on which an information reproduction program comprising an information reproduction procedure arranged according to the position of the enlarged basic block in the read image is recorded.

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