JP2000043343A - Printing system having pack bits control part and printing control method by pack bits control - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the amount of codes generated by a usual Pack Bits compression method in such a case that the same data appear repeatedly by the raster. SOLUTION: Regarding the data in a rectangular area which are coded by the byte by using a Pack Bits method (S2), comparison of lines is executed by the raster (S5) and, as to the data which appear in many times, tag information for discrimination is stored in addition in a data table (S9). By inserting the tag information into a code string at the time of compression (S8), it is made possible to refer to the data appearing in many times and thereby the total amount of data of compression codes is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a Pack Bit
Printing system having s control unit and PackBits
The present invention relates to a printing control method by control.

[0002]

2. Description of the Related Art Conventionally, binary data of a rectangular area is packed.
When encoding using the Bits compression method, data is processed in units of bytes. Therefore, (N
-1) Even when the line and the Nth line have the same data, the same code is generated separately for each line.

[0003]

However, in the above conventional example, when the same data as before appears repeatedly in raster units, there is a drawback that the amount of compression codes cannot be reduced.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and compares data of a rectangular area to be compressed with respect to preceding and succeeding lines in raster units.
For data with a large number of appearances, a tag for identification is added to the data table and stored, and the tag is inserted into the code string at the time of compression, thereby reducing the total amount of compressed codes and reducing raster data development time. Then, the data of the area to be compressed is compared with the previous line in raster units, and if the same raster continues, a new code is generated to reduce the total amount of compressed codes. is there. In order to achieve the above object, the present invention has the following configurations.

That is, a printing system having a Pack Bits control unit converts binary data of a rectangular area into Pack B data.
means for encoding the encoded data in units of bytes, means for comparing lines of the encoded data in units of raster, and registration of the same data if the data is not the same as the previous line by the comparison. Means for searching for presence or absence;
Means for inserting a registered coded sequence by referring to tag information in the case of registration based on the search, and attribute information for identifying tag information and occurrence frequency if the same as the previous line by the comparison. Means for updating and storing the updated data in the data table.

A printing system having a Pack Bits control unit converts binary data of a rectangular area into Pack B data.
a means for encoding the encoded data in byte units, a means for comparing the encoded data in lines in raster units, and a code in accordance with whether or not the data is the same as the previous line by the comparison. The main configuration is provided with a means for generating and a means for storing the code in a memory.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) FIG. 1 is a block diagram showing a case where the present invention is applied to an LBP control unit. In FIG. 1, reference numeral 101 denotes an I / F unit for exchanging data with a host computer (not shown); 102, a CPU serving as a microcomputer of the control unit; 103, a control program and various font data for printing; ROM, 1
Reference numeral 04 denotes a hard disk drive (HD) for storing large-capacity data (for example, various document formats for overlay, etc.). Reference numeral 105 denotes an NV for storing information on various LBP settings (paper size, character type, print offset, etc.).
RAM (non-volatile memory), 106 is DRAMCont
roller, 107 is DRAM, 108 is Pack
A control unit for generating / decoding Bits code, 109 is an operation panel, 110 is a VIDEO I / F unit of LBP, 111
Is an LBP engine.

FIG. 2 shows a Pack Bits control unit (108) and a DRAM Controller (1) in FIG.
06) in detail. 20
Reference numeral 1 denotes a line memory for temporarily storing binary data of a rectangular area in raster units at the time of compression, and reference numeral 202 denotes a compression control unit, which stores input binary data in raster units or bytes.
A comparator for comparing in units and a 7-bit counter for counting the number of repetitions of byte data, and Pack
It comprises a Bits (PB) code generator. 20
3 reads / wr the compressed data output from the code generation unit 202 to the drawing object memory 204;
or write the data expanded by the data expansion unit 206 to the Bit Map expansion memory 205.
This is a memory control unit that performs control to perform the te operation.

FIG. 3 is a memory map showing the usage of the DRAM (107) of FIG. 1 in this embodiment. Each is a system area used by the CPU of FIG. 1, a band
This is a drawing object area for storing intermediate data generated in units.

In the present embodiment, one page is divided into a plurality of pages, and real-time processing is performed with m lines as 1 band in order to realize a printing process with less memory. The above-mentioned band indicates this divided one band (see FIG. 4).

Other areas include a cache area used as a data table of the present invention, an area for down loading data from the host, and a buffer area for storing received print data.

FIG. 5 is a flowchart showing the flow of the processing of this embodiment. In S1, the data is sequentially stored in the line memory for each line of the rectangular area to be compressed.

In the next step S2, a pack in byte units
Performs Bits compression. In S4, the next line is read into the line memory, and in S5, the data is compared with the previous line to compare the lines in raster units. If they are not the same, a search is made in S7 to see if they have already been registered in the data table. If they have been registered, the coded sequence is inserted with reference to the tag (S8). Then, in S9, the value of the attribute of the number of appearances is increased by (+1), and writing is performed again in the data table.

Here, as an example in which the lines are the same, a raster scan of a character "" shown in FIG.
Row and k2 row. Tag information for identification is attached to each raster data (FIG. 7). For a line having a raster data structure with a large number of appearances, the raster encoded column of k1 rows is referred to by using the tag as an argument. It can be inserted as a raster encoded column of k2 rows.

On the other hand, if it is determined in S5 that it is the same as the previous line, registration is made in the data table using a data format as shown in FIG. In the raster scan of the character "" in FIG. 6, n-1 and n rows are the same.

In FIG. 7, a tag is an identification number assigned to each raster data. Where the number of times indicates the number of times the raster data has repeatedly appeared in the encoding up to the present. In the present embodiment, the tag is 00
It is four consecutive 256 bytes of (H) to FF (H) data. The raster data stores image data for one line of a rectangular area to be compressed. The raster data having such an attribute is stored in the line data table (207) shown in FIG. 2 and is referred to at the time of compression / expansion.

If the raster data is the same between adjacent lines, the data is registered with common tag information, and a tag is inserted into the compressed encoded sequence, thereby reducing the data amount of the compressed code. FIG. 8 shows that the tag of the present embodiment is Pac
This shows an example in which the k bits code is entered.

According to this embodiment, even when the same data repeatedly appears in raster units, the conventional Pack
There is an effect that the amount of codes generated by the Bits compression method can be reduced.

(Second Embodiment) In the first embodiment, the comparison is made for the entire width of the rectangular area.
As shown in FIG. 6, it is also possible to make a comparison only for the length w1> w2.

In FIG. 1, it is possible to store raster data of l, m, and n widths w2 in a data table. This embodiment is effective when processing a character having a large character size.

(Third Embodiment) FIG. 9 shows a circuit configuration of a data decompression unit in FIG. In the figure, reference numerals 901, 902, 903, and 904 denote 8bi of an input stage.
Data Latches of t width, 905 and 906 are gates for generating identification signals depending on whether the four Latches match or mismatch, 907 is a multiplexer for selecting Code or Data of Pack Bits for each byte, 908 Is a counter that counts repeated codes of PackBits, 910 is a Latch that collects expanded data in word units, 909
Is a sequencer that controls all the blocks described above. In the LBP control system configured as described above, print data sent from a host computer (not shown) shown in FIG.
It is stored in the reception buffer in the RAM. Receive Buf
When a certain amount of data is stored in fer, the RO of 103
The CPU of 102 performs analysis based on the program stored in M.

If the print data is a binary image, 1
The 08 Pack Bits control unit cuts out a certain rectangular area and performs compression in raster units. As an example in FIG.
The case where the kanji character “ta” is handled by a pixel having a height h and a width w is shown. At the time of compression, the line memory (20
In 1), two lines of data corresponding to the width w are stored. And 2
02, the (N-1) line and the N line are compared for equality, and if they are equal, a 4-byte continuous FF
FFFFFF (H) is output, and the (N + 1) th line is sequentially read into the line memory. If not equal, 8 pixels
Data is compared on a byte-by-l basis to generate normal Pack Bits data of (code) and (data).

FIG. 14 shows an example of a Pack Bits code generated based on the logic of the present invention. According to the data shown in the figure, the (N-1) th line and the Nth line are equivalent (because 4-byte continuous FFFFFFFF (H) is output), and the raster data is different from the (N + 1) th line. I understand.

In this way, the compressed binary image data of the rectangular area of height h and width w is stored in the drawing object memory (204) of FIG.

When a drawing object for m lines, which is a fraction of the area actually printed on the paper, can be prepared, the CPU of 102 controls the DRAM controller of 106.
The drawing object 204 is sequentially read out to the printer and the binary Bit Ma is output via the decompression unit 206.
The data is developed into p data, and the data is stored in the Bit Map development memory 205. In response to this, VIDEO I / F
The data sequentially read from the memory by the unit 110 is sent to the printer engine 111.

FIG. 10 is a timing chart showing the operation of the expansion circuit (FIG. 9). In FIG.
FFFFF (H) is detected, and R indicating the repetition of the previous line is detected.
The EPEAT signal is active. In response to this, the memory control unit 203 performs a batch write operation of one raster to the Bit Map development memory 205. From the next line, the bytes output from the last stage of the shift registers 301 to 304 are changed to 908 Count registers.
r, the CNTLD signal is made active, and the counter 908 loads the count number.

Until the counter carry (RCO) is output, the byte data from the shift registers 901 to 904 is latched in an output stage (width 32 bits) 910.
Keep setting to One word (32b) is stored in the latch.
When the data of (it) is prepared, the memory control unit 203 writes the data into the Bit Map development memory 205. Such a series of operations is performed until a binary image for h lines is generated in the BitMap development unit.

FIG. 12 is a memory map of the DRAM (107) of FIG. 1 in the present embodiment. A system area for an LBP control program area, a drawing object area for storing intermediate data generated in band units, and bit ma by rasterizing the intermediate data
p, a Map Map area for expanding to p, a Cache area used by the CPU of the LBP control unit, and a dow from the host.
Font area for storing n loaded Fonts, Receive Bu for storing print data from host
Used as the "ffer area".

FIG. 13 is a diagram showing that data to be developed in the Bit Map development area of FIG. 12 is generated by dividing one page of printing paper in units of m lines.

According to the present embodiment, when the same data repeatedly appears in raster units, the conventional Pa
This has the effect of reducing the amount of codes generated by the ck Bits compression method. In the above embodiment, Pac
Although the generation of the k Bits code has been performed by hardware, this processing can be performed by software.

[0030]

[Other Embodiments] Even if the present invention is applied to a system including a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copying machine) Machine, facsimile machine, etc.).

Another object of the present invention is to provide a storage medium storing a program code of software for realizing the functions of the above-described embodiments to a system or apparatus, and to provide a computer (or CPU) of the system or apparatus.
And MPU) read and execute the program code stored in the storage medium.

In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.

As a storage medium for supplying the program code, for example, a floppy disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD
-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like can be used.

When the computer executes the readout program code, not only the functions of the above-described embodiment are realized, but also the OS (Operating System) running on the computer based on the instruction of the program code. ) May perform some or all of the actual processing, and the processing may realize the functions of the above-described embodiments.

Further, after the program code read from the storage medium is written into a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, based on the instructions of the program code, It goes without saying that the CPU included in the function expansion board or the function expansion unit performs part or all of the actual processing, and the processing realizes the functions of the above-described embodiments.

[0036]

In the case where the same data repeatedly appears in raster units, there is an effect of reducing the amount of codes generated by the conventional Pack Bits compression method.

[0037]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an application to a printing apparatus according to a first embodiment.

FIG. 2 is a diagram showing a configuration of a compression / expansion circuit.

FIG. 3 is a diagram showing a memory map of FIG. 1;

FIG. 4 is a diagram illustrating band control of print processing according to the first embodiment.

FIG. 5 is a flowchart according to the first embodiment.

FIG. 6 is a diagram showing an example of binary data to which the present invention is applied.

FIG. 7 is a diagram showing a data format in a data table according to the present invention.

FIG. 8 is a diagram showing an example of a coded sequence according to the present invention.

FIG. 9 is a block diagram illustrating a decompression circuit according to a third embodiment.

FIG. 10 is a timing chart illustrating an expansion circuit according to a third embodiment.

FIG. 11 is a diagram illustrating binary data of a rectangular area according to the third embodiment.

FIG. 12 is a diagram illustrating a memory map of a DRAM.

FIG. 13 is a diagram illustrating band control of a printing apparatus according to a third embodiment.

FIG. 14 is a diagram illustrating a new code according to the third embodiment.

[Explanation of symbols]

 101 Host I / F Unit 102 CPU 103 ROM 104 Hard Disk Device 105 NVRAM 106 DRAM Controller 108 Pack Bits Control Unit 109 Operation Panel 110 VIDEO I / F Unit 111 Printer Engine

Claims (10)

[Claims] 1. A printing system having a Pack Bits control unit, comprising: means for encoding binary data of a rectangular area in units of bytes using a Pack Bits method; and line-coding the encoded data in units of rasters. Means for comparing the presence or absence of registration of the same data when the data is not the same as the previous line by the comparison; Means for inserting a coded column, and means for updating the attribute value for identifying the tag information and the occurrence frequency and storing the updated value in the data table when the result is the same as the previous line by the comparison. A printing system having a Pack Bits control unit that performs the operation. 2. The printing system according to claim 1, wherein the raster data can be compared by changing the data length of each line. 3. The printing system according to claim 1, wherein the tag information is information for identifying raster data for each line. 4. A printing system having a Pack Bits control unit, comprising: means for encoding binary data of a rectangular area in units of bytes using a Pack Bits method; and line-coding the encoded data in units of rasters. Pack Bits, comprising: a unit for performing a comparison of: a unit for generating a code based on whether or not the data is the same as the previous line by the comparison; and a unit for storing the code in a memory. A printing system having a control unit. 5. The printing system having a Pack Bits control unit according to claim 4, wherein, if the comparison indicates that the data is the same as the previous line, a 4-byte continuous code is output. 6. A printing control method based on Pack Bits control, comprising: encoding binary data of a rectangular area in byte units by using Pack Bits method; and converting the encoded data into line units in raster units. A step of performing a comparison; a step of searching for the presence / absence of the same data if the data is not the same as the previous line by the comparison; Inserting a column, and updating the attribute value for identifying the tag information and the frequency of occurrence when the result is the same as the previous line by the comparison and storing the updated value in a data table. A printing control method based on Pack Bits control. 7. The print control method according to Pack Bits control according to claim 6, wherein the raster data can be compared by changing the data length for each line. 8. The print control method according to claim 6, wherein the tag information is information for identifying raster data for each line. 9. A print control method based on Pack Bits control, comprising: encoding binary data of a rectangular area in byte units by using Pack Bits method; and converting the encoded data into line units in raster units. Pack Bits control, comprising the steps of: performing a comparison; generating a code based on whether or not the data is the same as a previous line by the comparison; and storing the code in a memory. Printing control method. 10. The print control method based on Pack Bits control according to claim 9, wherein, if the comparison indicates that the data is the same as the previous line, a code of 4 bytes continuous is output.