JPH0756589B2 - Character image data processor - Google Patents

Description

The present invention relates to a character image data processing device, and more particularly to a data compression technique.

[Conventional technology]

In recent years, an automatic typesetting machine has been proposed in which characters, symbols, etc. are projected on a cathode ray tube and the image is projected onto a photosensitive material through a lens to perform phototypesetting.

As a character signal generation technique used there, there is a technique in which a character is decomposed into many pixels and the presence or absence of an image in each pixel is output in association with digital "1" or "0".

[Problems to be solved by the invention]

In the conventional character signal generation technology described above, in the case of a complicated character such as Kanji, each character is, for example, at least 250 pixels x 2
It is necessary to decompose it into about 50 pixels.

Therefore, a storage capacity of 62,500 bits is required for each character, which makes the storage device expensive and impractical.

On the other hand, various techniques have been proposed for a character image data processing device that reduces storage capacity by compressing data.

For example, as shown in FIG. 5 (a), each pattern data P _A , P _B , P _C , and each of these patterns is applied to a pattern sequence 1 composed of different pattern data P _A , P _B , P _C. There is a repeat compression technique in which a pattern sequence 2 is obtained by storing the number of times data is repeated as a pair.

However, in this technique, as shown in FIG. 5 (b), with respect to the pattern sequence 3 in which different pattern data P _A , P _B , and P _C appear adjacently one after another, it is repeated for each pattern data. The pattern sequence 4 is accompanied by the number "1",
On the contrary, the amount of data to be stored increases, resulting in the inability to compress data.

The present invention has been made focusing on such a conventional problem, and when the same pattern data is repeated,
(EN) Provided is a character image data processing device which is converted into a sufficiently compressed pattern string and, when different pattern data appear adjacently, are converted into a pattern string and stored as it is.

In the description of the device according to the present invention, it is necessary to clearly express the order of input patterns.

Therefore, in the following description, the m-th input pattern is expressed as a pattern Pm.

Further, when paying attention to the contents of the pattern Pm, that is, when paying attention to the predetermined n-bit data itself forming each pattern, the pattern data Pm, or simply Pm
Express.

[Means for solving problems]

In the character image data processing device of the present invention, the pattern data Pm-1 immediately before the currently input pattern Pm is held in the data holding unit, and
The data comparator compares Pm and Pm-1. When the two data match, the repeat counter is incremented and the same pattern detection / holding unit holds the matching signal.

In addition, this same pattern detection holding unit is used for the next pattern Pm +
When 1 is input, the held coincidence signal of Pm = Pm-1 is output. That is, as shown in FIG. 1, paying attention to the time when the pattern Pm is input, the coincidence signal of Pm-1 = Pm-2 is output.

Next, the pattern data Pm and Pm-1 do not match,
Moreover, when the coincidence signal is output from the same pattern detection holding unit, based on the pattern data Pm-1 stored in the data holding unit and the count value Rc of the repeat counter, [Pm-1, Pm -1, Rc], the compressed data generating section outputs the compressed data.

On the contrary, the pattern data Pm and Pm-1 do not match,
Moreover, when the coincidence signal is not output from the same pattern detection holding unit, only the pattern data Pm-1 is output from the compressed data generating unit.

[Action]

When the pattern Pm of the character image is input, the data comparator compares this pattern data Pm with the pattern data Pm-1 of the data holding unit, and when Pm = Pm-1,
The repeat counter is incremented by way of the control unit and the coincidence is held in the same pattern detection holding unit.

Further, when Pm ≠ Pm-1, it is determined whether or not the stored content of the same pattern detection holding unit indicates Pm-1 = Pm-2, and Pm-1 = Pm-2 is inserted. In the case shown, the pattern data Pm-1 stored in the data holding unit
And the count value Rc accumulated in the repeat counter are sent to the compressed data generation section, and the compressed data generation section outputs compressed data composed of a series of data consisting of [Pm-1, Pm-1, Rc]. .

Further, when the determination result of the storage content of the same pattern detection section indicates that Pm-1 ≠ Pm-2, that is, when the same pattern data is not continuous, the Pm stored in the data holding section is stored. -1 pattern data is sent to the compressed data generation unit as it is, and the compressed data generation unit outputs Pm-1.
Pattern data is generated. This makes it possible to significantly reduce the storage capacity.

Example of Invention

FIG. 1 is a block connection diagram showing an embodiment of the character image data processing apparatus of the present invention. In parentheses, the patterns or signals output from the respective parts when the m-th pattern Pm is input are shown.

In the figure, reference numeral 30 is a data holding unit which previously fetches and holds the immediately preceding pattern data Pm-1, and 31 is the currently input pattern data Pm and the data holding unit 30.
Is compared with the pattern data Pm−1 held in Pm = Pm−
When it is 1, it is a data comparator that outputs a signal indicating that they match (hereinafter simply referred to as a match signal).

Reference numeral 32 is a control unit for performing various controls which will be described later in detail in relation to each operation, and 33 is a repeat counter (initial value Rc = 1) for counting the number Rc of times when the same pattern data is continuously repeated. .

34 holds the match signal output from the data comparator 31 when the previous pattern data is input, that is, when the pattern data Pm-1 is input to the data holding unit 30, and Pattern data Pm-1, Pm-2
The same pattern detection holding unit that stores that the two are the same, and outputs the same pattern detection signal indicating that they are the same,
Reference numeral 35 is a compressed data generator.

Next, the operation of the character image data processing device will be described based on this block diagram.

When the pattern data Pm is input, the data comparator 31 compares the previous pattern data Pm-1 already stored in the data holding unit 30 with this pattern data Pm.

When the data comparator 31 determines that Pm = Pm−1, a match signal indicating the determination result is supplied to the control unit 32, and the control unit 32 sets the repeat counter 33 to “1” based on the match signal. Step forward.

Further, at this time, the coincidence signal is also supplied to the same pattern detection / holding unit 34 to hold that they are in agreement (Pm = Pm−1).

When Pm ≠ Pm−1 and the match signal from the data comparator 31 disappears, that is, when pattern data different from the previous pattern data is input, the control unit 32 is supplied from the same pattern detection holding unit 34. Based on the presence / absence of the same pattern detection signal, Pm-1
= Pm-2 is determined.

When it is determined that Pm-1 = Pm-2, the pattern data Pm-1 stored in the data holding unit 30 and the count value Rc (≧ 2) accumulated in the repeat counter 33 are used as the compressed data generation unit. Supply to 35.

The compressed data generation unit 35 forms a data string of [Pm-1, Pm-1, Rc (≧ 2)] based on the data supplied by the above term and outputs it as compressed data.

FIG. 2A shows a pattern string for explaining the processing of the above pattern data, and here it is shown as a pattern string 41 when the input pattern data shown in FIG. 1 is P _A.

Next, if Pm ≠ Pm−1, and the same pattern detection holding unit
When the control unit 32 determines that the same pattern detection signal (Pm-1 ≠ Pm-2) from the 34 does not exist, the same pattern data is not repeated, so the compressed data generation unit 35 uses the data holding unit 30. The pattern data Pm-1 stored in is output as it is.

FIG. 2B shows the pattern string at this time, and here, it is shown as the pattern string 42 when the input pattern data is P _B , P _C , and P _D.

In other words, when different pattern data continues every time,
This is written as it is as a parallel pattern string.

FIG. 3 is a block connection diagram showing another embodiment of the invention.

In this embodiment, 36 is the input pattern data Pm
Is a 0 pattern detection unit that determines whether or not
Reference numeral 37 is a 0 pattern detection holding unit which stores that the pattern data Pm-1 immediately before is 0.

The same components as those in FIG. 1 are designated by the same reference numerals.

Next, the operation of the character image data processing apparatus according to another invention will be described with reference to this block diagram.

When the pattern data Pm is input, the 0 pattern detection unit
36 determines if it is zero.

Here, if Pm = 0, 0 is stored in the 0 pattern detection and holding unit 37.
The pattern detection signal is sent, and the 0 pattern detection holding unit 37 sets 0.
Holds that it is a pattern.

The data comparator 31 receives the input pattern data.
Pm and the pattern data Pm-1 stored in the data holding unit 30
Compare with.

When Pm = Pm−1, the control unit 32 advances the repeat counter 33 by “1” by the coincidence signal from the data comparator 31.

On the other hand, when Pm ≠ Pm−1, the control unit 32 discriminates the detection signals of the same pattern detection holding unit 34 and the 0 pattern detection holding unit 37, and the coincidence signal of the same pattern detection holding unit 34 (Pm−1 = Pm-2) and the detection signal (Pm-1 = 0) from the 0 pattern detection holding unit 37 are both output, the pattern data Pm-1 (=
0) and the counter value Rc (≧ 2) of the repeat counter 33 are sent to the compressed data generator 35.

The compressed data generator 35 outputs the compressed data of [“0”, Rc (≧ 2)]. This compressed data becomes like the pattern string 43 in FIG. 2 (c).

Further, the coincidence signal (Pm-1 = Pm of the same pattern generation unit 34
-2) is not detected and the detection signal (Pm-1 = 0) from the 0 pattern detection holding unit 37 is output, the pattern data Pm-1 (= 0) stored in the data holding unit 30 ,
Count value Rc (= 1) of the repeat counter 33 so far
To the compressed data generation unit 35.

At this time, the compressed data generator 35 [[0], Rc (=
1)] compressed data is output.

On the other hand, when the 0 pattern is not detected by the 0 pattern detector 36, the same operation as that described in FIG. 1 is performed.

As described above, in another embodiment of the present invention, when the pattern data of "0" is continuously repeated Rc times,
Since data compression is performed with [“0”, Rc], there is no compressed data that continues with “0” or “0” in the compressed data string.

Therefore, by setting a series of information "[0", "0"] as the function code, the compressed data can be used as a control code when decompressing (decoding) the original data.

FIG. 4 shows a specific example in the case of performing data compression using the present invention illustrated in the block diagram of FIG. 1 or FIG.

In the figure, reference numeral 50 is an example of an overall image of a character image to be data-compressed.

Reference numeral 51 is a partial image obtained by extracting a part of the character image 50. For example, 8-bit data shown as bit positions 0 to 7 at the left end is sequentially supplied to the data holding unit 30 as the pattern data.

(A), (b) and (c) shown in the lower part of the figure are code strings in which the pattern data before data compression or the pattern string after data compression is expressed in hexadecimal, for example, the code string (a) Is the bit position 4 (least significant) to 7 of the partial image 51.
4 bits consisting of (most significant) and 4 bits consisting of bit positions 0 (least significant) to 3 (most significant) are alternately expressed in hexadecimal.

Therefore, while the uncompressed pattern sequence is as shown in FIG. 4 (a), the pattern sequence when the data compression according to the embodiment of FIG. 1 is performed is as shown in FIG. 4 (b). ,
Further, the pattern sequence when the data compression according to the embodiment of FIG. 3 is performed is as shown in FIG. 4 (c). That is, it can be seen that the storage capacity can be significantly reduced.

〔The invention's effect〕

As described above, according to the device of the present invention, the following effects can be obtained.

When the same data as the pattern data Pm continues Rc times, it is described as [Pm, Pm, Rc] and the other data is described as it is, so that a high data compression rate can be obtained.

By writing the pattern data Pm that is continuously repeated twice like [Pm, Pm, Rc], a special code indicating that the data is continuous is not required.

Since no special code is provided, for example, the pattern data can be expressed using all bits of the n-bit pattern Pm.

When the pattern data of Pm = 0 is repeated Rc times consecutively, a higher data compression rate can be obtained by notating [“0”, Rc], and the data pattern of [“0”, “0”] The column can be used as a function code.

There is no need to provide a memory segment for every pixel that makes up a character image, the circuit is simple, and the overall size and cost of the memory device can be reduced, and the data processing speed is improved and the data transfer time is reduced. Complete.

As a result, a high-quality character image can be obtained even with a storage device having a small capacity.

[Brief description of drawings]

FIG. 1 is a block connection diagram showing an embodiment of an image data processing apparatus according to the present invention, FIG. 2 is an explanatory view showing a pattern sequence compressed by the present invention, and FIG. 3 shows an embodiment of another invention. FIG. 4 is a block connection diagram, FIG. 4 is an explanatory diagram showing an example of data compression of a character image, and FIG. 5 is an explanatory diagram showing a conventional compressed pattern sequence. 30 …… Data holding unit 31 …… Data comparator 32 …… Control unit 33 …… Repeat counter 34 …… Same pattern detection holding unit 35 …… Compressed data generation unit

 ─────────────────────────────────────────────────── ───Continuation of the front page Judgment panel Judge General Masahide Sakai Judge Keiko Kakizawa Judge Morinzo Iseki (56) References JP 50-16420 (JP, A) JP 58-173791 (JP, A) )

Claims (2)

[Claims] 1. A character image data compression apparatus for compressing data while successively inputting character image data divided into n-bit pattern data, wherein the pattern data Pm- is the pattern data Pm- 1 is compared with the pattern data Pm currently input and the pattern data Pm-1 held in the data holding unit 30 are compared, and Pm
Data comparator that outputs a coincidence signal when = Pm-1
31, a repeat counter 33 that counts the number Rc of times when the same pattern data is continuously repeated, and a match signal output from the data comparator 31 when the pattern data Pm-1 is input to the data holding unit 30. By holding the two previous pattern data
The same pattern detection holding unit 34 that holds that Pm-1 and Pm-2 are the same and outputs the same pattern detection signal, and the repeat counter 33 based on the coincidence signal output from the data comparator 31 1 "step by step, and when the coincidence signal from the data comparator 31 disappears, based on the presence / absence of the same pattern detection signal output by the same pattern detection holding unit 34, the following first set or second set Of the pattern data Pm− held in the data holding unit 30 and the control unit 32 that outputs any of the data of the above as compressed data creation data.
The first set of data consisting of 1 and the count value Rc accumulated in the repeat counter 33. b. Pattern data Pm− held in the data holding unit 30
A second set of data consisting of only ones. When the first set of data is supplied from the control unit 32, a data string of [Pm-1, Pm-1, Rc] is formed and output as compressed data, and the second set is output from the control unit 32. And a compressed data generation unit 35 that outputs only Pm-1 data as compressed data, the character image data processing device. 2. A character image data compression device for compressing data while sequentially inputting character image data divided into pattern data consisting of n bits, wherein pattern data Pm- 1 is compared with the pattern data Pm currently input and the pattern data Pm-1 held in the data holding unit 30 are compared, and Pm
Data comparator that outputs a coincidence signal when = Pm-1
31, a repeat counter 33 that counts the number Rc of times when the same pattern data is continuously repeated, and a match signal output from the data comparator 31 when the pattern data Pm-1 is input to the data holding unit 30. By holding the two previous pattern data
The same pattern detection holding unit 34, which holds that Pm-1 and Pm-2 are the same and outputs the same pattern detection signal, is discriminated whether or not the input pattern data Pm is 0. If = 0, 0 for outputting 0 pattern detection signal
By inputting the pattern detection unit 36 and the 0-pattern detection signal, the pattern data Pm-1 immediately before is held at 0.
Based on the match signal output from the pattern detection holding unit 37 and the data comparator 31, the repeat counter 33 is incremented by "1", and when the match signal from the data comparator 31 disappears, the same pattern detection is performed. Presence / absence of the same pattern detection signal output by the holding unit 34, and 0 pattern detection holding unit
Based on the presence / absence of 0 pattern detection signal output from 37,
A control unit 32 for outputting any of the following first to fourth sets of data as data for creating compressed data, and a. Pattern data Pm− held in the data holding unit 30.
A first set of data consisting of 1 (= 0) and a counter value Rc (≧ 2) accumulated in the repeat counter 33. b. Pattern data Pm− held in the data holding unit 30
A second set of data consisting of 1 (= 0) and the counter value Rc (= 1) accumulated in the repeat counter 33. c. Pattern data Pm− held in the data holding unit 30
A third set of data consisting of 1 (≠ 0) and the count value Rc (≧ 2) accumulated in the repeat counter 33. d. Pattern data Pm- held in the data holding unit 30
A fourth set of data consisting of only 1 (≠ 0). When the first set of data is supplied from the control unit 32, a data string of [“0”, Rc (≧ 2)] is formed, and the control unit 32
When the second set of data is supplied from [1], a data string of [“0”, Rc (= 1)] is formed, and when the third set of data is supplied from the control unit 32, [Pm
-1, Pm-1, Rc (≧ 2)], and these constructed data strings are used as compressed data. If the fourth set of data is supplied from the control unit 32, Pm-1 Compressed data generator 35 that outputs only the data of
And a character image data processing device.