JP2001111432A - Data compression controller, method for controlling data compression, printing information forming device, printing system, and recording medium recording program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data compression controller and a controlling method capable of selecting data compression/non-compression in accordance with the transfer speed of a communication interface and the compression ratio of data and to provide also a printing information forming device and a recording medium recording a program. SOLUTION: Data loss caused by compression/restoration processing can be solved by judging the transfer speed of the communication interface, compressing data and sending the compressed data when the transfer speed may cause the bottleneck of the whole process or sending the non-compressed data as it is in the other case. Since the compression ratio of transmission data is previously inspected and compressed data are sent only when the compression ratio of a prescribed value and over is obtained, communication data can be compressed only when a compression effect is surely obtained. Thereby the load of peripheral equipment for receiving the compressed data and restoring the data can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data compression control device, a data compression control method, a print information forming device, a printing system, and a recording medium on which a program is recorded. More specifically, the present invention relates to a data compression control device capable of appropriately determining whether to compress data according to the transmission speed of a communication interface when transmitting data via the communication interface, The present invention relates to a control method, a print information forming apparatus, a printing system, and a recording medium on which a program is recorded.

[0002]

2. Description of the Related Art In recent years, communication interfaces between a host device and peripheral devices have been diversified. For example, in the case where a printer or scanner is connected to a personal computer, for example, the personal computer is provided with both a parallel communication interface and a serial communication interface. In many cases, any one of them can be appropriately selected and used. Furthermore, peripheral devices such as printers and scanners also have a plurality of communication interfaces, and any of them can be arbitrarily selected and connected to a host device.

Hereinafter, a computer and a printer will be described as examples in which a host device and a peripheral device are connected.

FIG. 13 is a block diagram conceptually showing a printing system in which a host computer and a printer are connected.

[0005] The host computer 100 is provided with a control unit 110 implemented by software commonly called a "printer driver". This control unit 110
Receives “image data” to be printed in the host computer 100, converts the “image data” into “print data”,
The “print data” is sent to a printer to execute printing.

The control unit 110 includes an interface 12
0 and 210, data can be exchanged with the printer 200. The printer engine 250 includes a print head and a paper feed mechanism (not shown), receives predetermined data via the interface 210, and executes a printing operation.

Here, the data transfer rates of the communication interfaces 110 and 210 frequently used for data communication between the host computer 100 and the printer 200 are as follows. In the following notation,
The unit “bps” of the data transfer speed is an abbreviation of “bit per second”, and “USB” is “Universal Serial Bus”.
s ”. Communication interface (setting mode) Data transfer speed Parallel (compatible mode) 100 Kbps parallel (compatible + DMA mode) 500 Kbps parallel (ECP mode) 1 Mbps USB (low speed mode) 1.5 Mbps USB (full speed mode) 12 Mbps IEEE 1394 100 M to 2 Gbps

[0008]

In the printing system illustrated in FIG. 13, a part that can be a "bottleneck" in the printing process is the communication interfaces 120 and 21.
0 and a printer engine 250 with mechanical operations. At present, the processing speed of the printer engine of the “inkjet printer” most widely used as a personal printer is about 500 Kbps in terms of data amount, which is faster than the above-described parallel communication interface compatible mode (100 Kbit / sec). .

That is, when the compatible mode is selected from a plurality of prepared communication interfaces, the data processing speed of the communication interfaces 120 and 210 falls below the data processing speed of the printer engine 250, and the entire printing process is rate-determined. It becomes a "bottleneck".

In a situation where a plurality of types of communication interfaces are prepared and it is not known which one is selected, a "bottleneck", that is, a certain processing speed is ensured even when the interface having the lowest transfer speed is used. It is necessary to. That is, it is necessary to compress the data in order to reduce the processing time at the bottleneck. For this reason, in a conventional printing system, usually, a compression unit 114 is provided in the control unit 110 to perform data compression. In response, the printer 200
Restores the compressed data received via the interface 210 in the decompression unit 220,
Send to 50.

In the case of a printing system using an ink-jet printer, “run length compression” is often used as a data compression method in the compression section 114. This is because when data of the same value is continuous in the digital data string, the data is replaced by data obtained by combining the "compressed display header", the "number of continuous data (run length)", and the "data value". It is a way to reduce the amount.

Referring to the example of FIG. 13, the computer 1
A control unit (printer driver) 110 provided in the printer 100 converts the image data into print data, and further executes run-length compression on the obtained print data and transmits the print data to the printer 200. The printer 200 decompresses the run-length compressed data by the decompression unit 220 and executes a printing process.

That is, conventionally, in order to cope with a communication interface having the lowest transfer speed, a data compression process in the host device and a data restoration process in the printer have been provided.

However, as the communication interface evolves, the transfer speed of an interface actually used, such as a USB interface, is often much higher than that of an interface that becomes a “bottleneck”. Until such a high-speed communication interface is selected, if data is compressed and transmitted, the burden on the CPU (Central Processing Unit) will only be increased, and other tasks will be squeezed.

Further, depending on the contents of data to be transmitted and the transfer speed of the interface, an increase in processing time for data compression / decompression may be larger than a reduction in transfer time due to compression. In other words, there is a case where the demerit due to the labor of compression / decompression is greater than the merit of compressing the data.

Further, there is actually a case where the data amount increases when compression is performed.

The present invention has been made based on the recognition of such a problem. That is, the object is to record a data compression control device, a data compression control method, a print information forming device, and a program which can select compression / non-compression of data according to the transfer speed of the communication interface and the data compression ratio. It is to provide a recording medium.

[0018]

In order to achieve the above object, a data compression control device according to the present invention is a data compression control device for controlling a compression process of data to be transmitted, wherein the data compression control device compresses data. And a path selecting means for selecting a processing path for the data to be transmitted, wherein the path selecting means determines whether or not the data to be transmitted is compressed by the compression means. It is characterized by being determined according to a physical or logical type.

According to the above configuration, it is possible to prevent data compression from being performed even when the communication interface is high speed, and to perform efficient processing without the need for compression / decompression.

Here, the physical or logical type of the communication interface can be determined when the communication interface is connected to the communication interface.

Alternatively, the physical or logical type of the communication interface may be determined each time data is transmitted.

Further, the apparatus further comprises a compression ratio checking unit for checking a compression ratio of data to be transmitted by the compression unit, wherein the path selecting unit determines whether or not the data to be transmitted is compressed by the compression unit. Is determined according to the physical or logical type of the communication interface that transmits the data, and only when the compression ratio checked by the compression ratio checking unit is higher than a predetermined value, the data to be transmitted is compressed by the compression unit. May be determined to be compressed and output. In this way, data compression can be performed only when the effect of compression can be reliably obtained by further checking the compression ratio.

Further, first storage means for storing the data to be transmitted in an uncompressed state, and second storage means for storing data obtained by compressing the data to be transmitted by the compression means. And the compression ratio inspection unit compares the uncompressed data stored in the first storage unit with the compressed data stored in the second storage unit. Checking the compression ratio, and when it is determined that the data to be transmitted is compressed and output, the path selection means supplies the compressed data stored in the second storage means to the interface. When it is determined that the data to be transmitted is not compressed and output, the uncompressed data stored in the first storage means may be supplied to the interface. . In this case, any of the data stored in the respective storage means may be output,
Efficient processing becomes possible.

Alternatively, if the compression rate inspection means predicts the compression rate without using data obtained by compressing the data to be transmitted by the compression means,
Inspection of the compression ratio can be performed quickly in a short time.

[0025] Further, if the physical or logical type of the communication interface is a type having a high transfer rate, the route selecting means determines that the data to be transmitted is not to be compressed. Data compression can be prevented from being performed even when the interface is high-speed, and efficient processing can be performed without the need for compression and decompression.

On the other hand, a data compression control method according to the present invention is a data compression control method for controlling a compression process of data to be transmitted, wherein a communication interface for transmitting data determines whether or not to compress data to be transmitted. Is determined according to the physical or logical type of

According to the above configuration, it is possible to prevent the data compression from being performed even when the communication interface is high-speed, and it is possible to perform efficient processing while saving the trouble of compression / decompression.

On the other hand, a print information forming apparatus of the present invention is a print information forming apparatus for forming print information of an image to be printed on a print image forming medium such as paper, and generates print data by inputting image data. A print data generation unit; a compression control unit that controls a compression process of the print data generated by the print data generation unit; the compression control unit includes a compression unit that compresses the print data; Path selection means for selecting a processing path for print data;
Wherein the path selecting means determines whether or not to compress the print data to be transmitted by the compressing means in accordance with the physical or logical type of the communication interface for transmitting the print data. I do.

According to the above configuration, it is possible to prevent data compression from being performed when the communication interface between the print information forming apparatus and a printing apparatus such as a printer is high-speed, and to save time and effort for compression and restoration. Processing can be performed.

On the other hand, a printing system according to the present invention forms a print information forming apparatus for forming print information of an image to be printed, and forms a predetermined image on a print medium by using the print information generated by the print information forming apparatus. A printing apparatus, wherein the print information forming apparatus comprises:
A print data generation unit for inputting image data to generate print data; and a compression control unit for controlling a compression process of the print data generated by the print data generation unit, wherein the compression control unit Compression means for compressing, and a path selection means for selecting a processing path for the print data to be transmitted, the path selection means, whether to compress the print data to be transmitted by the compression means, Determined according to the physical or logical type of the communication interface for transmitting the print data, wherein the printing apparatus receives the print data from the print image forming apparatus and the print data is compressed Is characterized in that a predetermined image is formed on a print medium by restoring.

According to the above configuration, it is possible to prevent the data compression from being performed even when the communication interface between the print information forming apparatus and the printing apparatus is high-speed, and to save time and effort in the compression and decompression to perform efficient processing. Can be possible.

On the other hand, a recording medium of the present invention is a computer-readable recording medium storing a program for controlling a compression process of data to be transmitted, wherein the program is a compression module for compressing data to be transmitted. And determining whether to compress and output the data to be transmitted by the compression module according to the physical or logical type of the communication interface for transmitting the data.

Here, in the present specification, the “recording medium” is, for example, a hard disk (HD), a DVD-
RAM, DVD-ROM, magneto-optical recording medium, flexible disk (FD), CD-ROM, etc.
Various memories such as M and ROM are also included.

In addition, programs to be recorded on these media may be used as they are, or may be encrypted, modulated, or compressed as necessary, using a wired line such as an intranet or the Internet, or wireless. It may be distributed via a line.

[0035]

Embodiments of the present invention will be described below with reference to the drawings.

(First Embodiment) First, the first embodiment of the present invention will be described.
As an embodiment of the present invention, there will be described a data compression control device which determines the compression / non-compression by checking the transfer speed of the communication interface in advance when setting the system.

FIG. 1 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to the present embodiment. That is, in FIG.
00 and the peripheral device 200 are interfaces 120, 2
10 are connected. In the host device 100,
A data compression control device 10A is provided, and controls whether data to be transmitted to the interface is compressed or not.

The data compression control device 10A has a path selection means 12, a selection information storage means 13, a compression means (compression module) 14, and a transfer speed determination means 16. Data to be transmitted to the peripheral device 200 is input to the route selection unit 12.

The path selecting means 12 determines whether data to be transmitted to the peripheral device 200 is compressed or uncompressed, and selects a processing path for the input transmission data.

The selection information storage means 13 checks the transfer speed of the communication interface in advance at the time of setting the system, etc.
This is means for storing selection information corresponding to the selection information.

The compression means 14 compresses the input data and outputs it. As the compression method, in addition to the above-described run-length compression, any method such as data coding, Huffman coding, and arithmetic coding can be used.

The operation of the data compression control device 10A having the above-described configuration will be described below.

FIG. 2 is a flowchart showing a schematic operation of the data compression control device 10A.

In the flowchart, step S1
Steps 0A to S16 are mainly executed when the system is set. On the other hand, steps S20 to S32
Is a step executed at the time of normal data transmission.

First, in step S10A, a communication interface is specified. That is, the communication interface to which the data compression control device 10A is connected and the setting mode thereof are specified. This can be performed, for example, by checking which of a plurality of data input / output ports provided in the host device 100 is selected, which communication mode is set, and the like. Or, for the peripheral device 200,
It is also possible to determine the data transfer rate by actually transmitting the predetermined test data.

When the host device 100 is a computer, the communication interface can be specified by checking the "port driver". This specification can be executed, for example, by the route selection unit 12 or the selection information storage unit 13.

Alternatively, in step S10A, the user
It may be executed by inputting the type of communication interface and the setting mode.

Next, in step S12, it is determined whether the transfer speed of the specified communication interface is lower than a predetermined speed. This determination is performed, for example, by the route selection unit 12. Here, the “predetermined speed” can be defined as, for example, the maximum transfer speed that can control the entire target process. That is, in the target process, it can be defined as the transfer speed (or data processing speed) of the slowest part excluding the interface unit.

Here, the "target process" means a process to be performed in the peripheral device 200. When the peripheral device 200 is a printer, a printing process is performed. When the peripheral device 200 is a display device, a display process is performed. In the case of, the conversion process,
In the case of a motor or an actuator, this is processing such as mechanical operation processing. Therefore, in the case of the printing system illustrated in FIG. 13, the data processing speed of the printer engine 250 can be set to the “predetermined speed”. Further, as will be described in detail later, the effect of data compression may be taken into account when determining the “predetermined speed”.

Returning to FIG. 2, if the transfer speed of the interface is lower than the "predetermined speed" (step S1)
2: Yes) proceeds to step S14A and sets the selection information to “route A”. On the other hand, when the transfer speed of the interface is equal to or higher than the "predetermined speed" (step S12: N
In o), the process proceeds to step S14B, where the selection information is set as “route B”. These paths A and B correspond to data compression / non-compression paths as shown in FIG.

Next, in step S16, these pieces of selection information are stored in the selection information storage means 13. This is the process of “initial setting” or “change of setting”. That is, in the process up to this point, whether to compress data is determined according to the transfer speed of the communication interface, and the information is stored in the selection information storage unit 13.

As described above, steps S10A to S10S
When the "setting" of the system is performed by the user 16, the data transmission operation can be performed. "Setting" of this system can be executed when the hardware of the present invention, that is, the data compression control device is connected to the communication interface. Alternatively, the program stored in the recording medium of the present invention can be executed at an initial setting stage after being installed in a computer.

When the "setting" of the system is completed in this way, an actual data transmission operation can be executed.

That is, in step S20, the route selecting means 12 inputs data to be transmitted.

Next, in step S22, the route selection means 12 checks the selection information stored in the selection information storage means 13.

When the selection information stored in the selection information storage means 13 is "route A" (step S24: Y
es) In step S26A, the path selecting unit 12 selects “path A” and sends the data. As a result, the transmission data is compressed by the compression means 14 (step S28) and output (step S30).

On the other hand, when the selection information stored in the selection information storage means 13 is "route B" (step S2).
4: No) indicates that the route selection unit 12 determines in step S26B
, "Path B" is selected and data is transmitted. As a result, the transmission data is output to the interface 120 in an uncompressed state (step S30).

When the communication interface or its setting mode is changed (step S32: Yes)
Returns to step S10A and executes the setting operation of the system again. On the other hand, when there is no change in the setting (step S
32: No) returns to step S20 to wait for the next transmission data.

As is clear from the above description, steps S10A to S16 in the flowchart of FIG.
This is a step executed when setting the system. For example, when the data compression control device 10A of the present embodiment is realized by installing software called a “driver” or the like on a computer, the “initial setting” or “change of setting” of the driver can be performed. At this time, steps S10A to S16 can be executed.

On the other hand, steps S20 to S32
Is a step executed when normal data is transmitted after software is installed and settings are completed.

The peripheral device 200 determines whether or not the received data is compressed and performs appropriate processing.

As described above, the data compression control device of this embodiment compresses / decompresses data according to the transfer speed of the communication interface. For example, if the transfer rate of the communication interface can be a "bottleneck" in the entire process, the data can be compressed and sent; otherwise, the data can be sent uncompressed. In this way, when a communication interface with a peripheral device having a low transfer speed is used, the data is compressed to shorten the transfer time. On the other hand, when an interface having a high transfer rate is used, data is transmitted in an uncompressed state, and the loss associated with compression / decompression processing is eliminated.

FIG. 1 shows a configuration example in which the data compression control device 10A is provided only in the host device 100, but the present invention is not limited to this. That is, when the host device 100 and the peripheral device 200 perform two-way communication, it goes without saying that the peripheral device 200 may be provided with a similar data compression control device.

As described above, the "predetermined speed" used as a criterion for determination of compression / non-compression in the present embodiment is, as described above, the slowest part (ex. In the example, it can be defined as the data processing speed of the printer engine 250), but may be further determined in consideration of the data compression ratio and the time of the compression / decompression processing. For example, if the compression ratio of data transmitted from the host device 100 to the peripheral device 200 is substantially constant and the compression / decompression processing time can be roughly predicted, the transmission time is reduced by compressing the data. The “predetermined speed” can be relatively easily determined in consideration of the effect and the increase in the time required for the compression / decompression processing. In this case, the “predetermined speed” is obtained by multiplying the data processing speed of the slowest part (for example, the printer engine 250 in the example of FIG. 13) of the target process except the interface unit by a predetermined coefficient. Can be defined as

(Second Embodiment) Next, a second embodiment of the present invention will be described.
As an embodiment of the present invention, a description will be given of a data compression control device which determines the transfer speed of a communication interface as needed, and controls the compression / non-compression of data accordingly.

FIG. 3 is a block diagram conceptually showing the configuration of a communication system including the data compression control device according to the present embodiment. That is, in FIG.
00 and the peripheral device 200 are interfaces 120, 2
10 are connected. In the host device 100,
A data compression control device 10B is provided, and controls whether or not data to be transmitted to the interface is compressed.

The data compression control device 10 B has a path selecting means 12, a compressing means (compression module) 14, and a transfer speed judging means 16. Data to be transmitted to the peripheral device 200 is input to the route selection unit 12.

The path selection means 12 determines whether data to be transmitted to the peripheral device 200 is compressed or uncompressed, and selects a processing path for the input transmission data.

The compression means 14 compresses the input data and outputs it. As a compression method, in addition to the above-described run-length compression, for example, data coding, Huffman coding, and the arithmetic transfer rate determining unit 16 determine the data transfer rate of the interface 120, and select the result as a path selection. Report to means 12.

The operation of the data compression control device 10B having the above-described configuration will be described below.

FIG. 4 is a flowchart showing a schematic operation of the data compression control device 10B.

First, in step S10B, the determination means 16 determines the data transfer speed of the interface 120. This can be performed, for example, by checking which of a plurality of data input / output ports provided in the host device 100 is selected, which communication mode is set, and the like. Alternatively, the data transfer rate can be determined by actually transmitting predetermined data to the peripheral device 200. The transfer rate determining means 16 reports the result of the transfer rate determination to the path selecting means 12 via the path C.

Next, in step S12, it is determined whether or not the transfer speed determination value is lower than a predetermined speed. This determination is performed, for example, by the route selection unit 12. Here, the “predetermined speed” can be defined as, for example, the maximum transfer speed that can control the entire target process. That is, in the target process, it can be defined as the transfer speed (or data processing speed) of the slowest part excluding the interface unit.

Here, the "target process" means a process to be performed in the peripheral device 200. When the peripheral device 200 is a printer, a printing process is performed. When the peripheral device 200 is a display device, a display process is performed. In the case of, the conversion process,
In the case of a motor or an actuator, this is processing such as mechanical operation processing. Therefore, in the case of the printing system illustrated in FIG. 13, the data processing speed of the printer engine 250 can be set to the “predetermined speed”. Further, as will be described in detail later, the effect of data compression may be taken into account when determining the “predetermined speed”.

Returning to FIG. 4, if the transfer speed of the interface is lower than the "predetermined speed" (step S1)
(2: Yes) The process proceeds to step S26A, where the path selection unit 12 selects the path A and inputs data to the compression unit 14.

The input data is compressed in step S28 and output to the interface 120 in step S30.

On the other hand, when the transfer speed of the interface is equal to or higher than the "predetermined speed" (step S12: No),
Proceeding to step S26B, the route selecting means 12 selects the route B. That is, the data is output to the interface 120 in a non-compressed state in step S30 without passing through the compression unit 14. The peripheral device 200
Determines whether the received data is compressed data and performs appropriate processing.

As described above, the data compression control device of this embodiment determines the transfer speed of the communication interface as needed, and if this can be a “bottleneck” in the entire process, compresses and sends out the data. Otherwise, the data is sent uncompressed. In this way, when a communication interface with a peripheral device or a setting mode having a low transfer speed is selected, the data is compressed to shorten the transfer time. On the other hand, when an interface with a high transfer rate or a transfer mode is selected, the data is transmitted in an uncompressed state, thereby eliminating the loss associated with the compression / decompression processing. This embodiment is particularly effective in applications where the transfer speed of the communication interface is frequently switched.

In FIG. 2, the host device 100
Although the configuration example in which the data compression control device 10 </ b> A is provided is described only in the above, the present invention is not limited to this. That is, when the host device 100 and the peripheral device 200 perform two-way communication, it goes without saying that the peripheral device 200 may be provided with a similar data compression control device.

Also, in the present embodiment, the "predetermined speed" as a criterion for determination of compression / non-compression can be appropriately determined as described above with reference to the first embodiment.

(Third Embodiment) Next, a third embodiment of the present invention will be described.
As an embodiment of the present invention, a description will be given of a data compression control device that dynamically checks the compression ratio of data to be transmitted and determines whether to compress or not to compress.

FIG. 5 is a block diagram conceptually showing the configuration of a communication system including the data compression control device according to the present embodiment. That is, the host device 100 and the peripheral device 2
00 are connected via interfaces 120 and 210. The host device 100 is provided with a data compression control device 10C. Data compression control device 10C
Regarding the details of each element part, the same parts as those described above with reference to FIGS. 1 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Data compression control device 10C of the present embodiment
Is the route selection means 12 described above with reference to FIGS.
In addition to the compression means 14 and the transfer speed determination means 16, the storage means 11 and 15 and the compression ratio inspection means 18 are provided. The storage means 11 is provided at the input stage of the data compression control device 10B and has a role of buffering transmission data as it is. The storage means 15 is provided after the compression means 14,
Buffer the compressed transmission data. The compression ratio inspection unit 18 has a role of inspecting the compression ratio when the data to be transmitted is compressed by the compression unit 14, and reporting the result to the path selection unit 12.

The path selection means is connected to the output stage of the storage means 11 and the storage means 15 and sends out any of the data buffered in these to the interface.

FIG. 6 is a flowchart showing a schematic operation of the data compression control device 10C of the present embodiment. In the flowchart, the same steps as those described above with reference to FIG. 4 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In the present embodiment, step S10B
To determine the transfer speed of the interface, and step S1
In step S2, it is determined whether the transfer speed is lower than the predetermined speed.
In s), the compression ratio of the transmission data is actually measured in step S13A. That is, the transmission data buffered in the storage unit 11 is sent to the compression unit 14 to be compressed, and is buffered in the storage unit 15. Then, the compression ratio inspection unit 18 calculates the compression ratio by comparing the transmission data amounts buffered in the storage unit 11 and the storage unit 15, respectively, and reports the compression ratio to the path selection unit 12. In the specification of the present application, the “compression ratio” is defined as a value obtained by dividing the data amount before compression by the data amount after compression. That is, the higher the “compression ratio”, the smaller the data amount after compression.

When the compression ratio checker 18 checks the compression ratio of the transmission data as described above, it reports the result to the route selector 12.

Next, in step S13B, it is determined whether or not the compression ratio is equal to or more than a predetermined value. Then, when the compression ratio is equal to or more than a predetermined value (Step S13B: Yes)
Indicates that compressed data is selected in step S29A,
It is output in step S30. That is, the compressed data buffered in the storage unit 15 is selected by the path selection unit 12 and transmitted.

On the other hand, if the compression ratio is less than the predetermined value (step S13B: No), the process proceeds to step S29B, where uncompressed data is selected and output in step S30. That is, the uncompressed data buffered in the storage unit 11 is selected by the path selection unit 12 and transmitted.

As described above, in the present embodiment, the transmission data is compressed and output only when the transfer speed of the communication interface is lower than the predetermined speed and the compression ratio of the transmission data is equal to or higher than the predetermined value. Therefore, according to the present embodiment, in addition to the functions and effects described above with respect to the first embodiment, there is also obtained an effect that a compression effect is reliably obtained.

That is, depending on the contents of the transmission data,
Even if compression is performed, a very high compression ratio may not be obtained. In such a case, the disadvantage of increasing the work of compression / decompression is greater. Further, in an extreme case, when the data is compressed by the compression means 14, the data amount may be increased.

According to the present embodiment, the compression ratio of transmission data is checked in advance, and compressed data is transmitted only when a compression ratio equal to or more than a "predetermined value" is obtained. For example, step S
If the "predetermined value" of the compression ratio in 13B is "1",
Communication is performed with compressed data only when the compression ratio is 1 or more.
Therefore, when the data amount increases as a result of the compression, the non-compression can be selected and avoided. Further, for example, if the "predetermined value" of the compression ratio is set to "1.3" or the like, communication can be performed with the compressed data only when a compression ratio higher than this can be obtained.

Therefore, the above-described problem can be solved, and the transmission data can be compressed only when the effect of the compression is reliably obtained.

In this embodiment, there is a case where the transmission data is compressed and uncompressed data is transmitted as a result of the determination (step S29B). In this way, the burden on the peripheral device receiving the data to restore the compressed data is also eliminated. Host device 100 for sending data
Is often provided with a CPU having a high processing capability such as a personal computer. Therefore, the load of the compression process is relatively small.

On the other hand, C
The processing capacity of a PU is often limited. Therefore, reducing the process of restoring the compressed data imposed on the CPU of the peripheral device 200 is effective for making the system operate smoothly.

The specific example shown in FIG. 5 is obtained by adding “storage means 11”, “storage means 15”, and “compression rate inspection means 18” to the configuration example of the second embodiment shown in FIG. Corresponds to the example. However, the present invention is not limited to this.

FIGS. 7A and 7B show "storage means 11" and "storage means 1" for the configuration example described above as the first embodiment of the present invention.
FIG. 5 is a block diagram showing a data compression control device to which "compression ratio inspection means 18" is added.

FIG. 8 is a flowchart showing the operation of the data compression control device 10D of FIG.

Since the details of the specific examples shown in FIGS. 7 and 8 can be the same as those described above with reference to FIGS. 1 to 6, the same components and steps are denoted by the same reference numerals. Detailed description is omitted.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.
An embodiment will be described.

In the present embodiment, the compression ratio of transmission data is checked by prediction.

FIG. 9 is a block diagram conceptually showing the configuration of a communication system including the data compression control device according to the present embodiment.

FIG. 10 is a flowchart showing a schematic operation of the data compression control device 10E of the present embodiment.

Also in these figures, the same parts as those described above in FIGS. 1 to 8 are denoted by the same reference numerals, and detailed description thereof will be omitted.

Data compression control device 10E of the present embodiment
Are the route selection means 12 described above with reference to FIGS.
It has a compression unit 14, a transfer speed determination unit 16, and a compression ratio inspection device 18. However, the compression ratio inspection unit 18 of the present embodiment
Predicts the compression ratio of the data to be transmitted. That is,
When the transfer speed of the communication interface is lower than the predetermined speed in step S12 of FIG. 10 (step S12).
12: Yes) predicts the compression ratio of the transmission data in step S13C.

As a method of predicting the compression ratio, for example,
The compression means 14 samples only a part of the transmission data and
To calculate the compression ratio. According to this method, the inspection time can be reduced.

Alternatively, there is a method in which a simple compression is tried for all or a part of the transmission data, and a final compression ratio is predicted from the result. As a simple compression method, for example, there is a method of executing only a part of the compression process in the compression unit 14 and predicting a final compression ratio from the result. Alternatively, the final compression ratio may be predicted by statistically analyzing or classifying the bit arrangement pattern of the transmission data. The inspection time can be reduced even by using such a “simple compression method”.

When the compression ratio check unit 18 checks the compression ratio of the transmission data as described above, it reports the result to the route selection unit 12.

Next, in step S13B, it is determined whether or not the compression ratio is equal to or more than a predetermined value. Then, when the compression ratio is equal to or more than a predetermined value (Step S13B: Yes)
Is selected in step S26A, compressed in step S28, and output in step S30.

On the other hand, if the transfer speed is equal to or higher than the predetermined speed (step S12: No) or if the compression ratio is lower than the predetermined value (step S13B: No), the process proceeds to step S13.
The process proceeds to 26B, where path B is selected, and uncompressed data is output in step S30. The route selection means 12
A storage unit (not shown) may be provided to buffer uncompressed transmission data.

As described above, also in this modified example, the transmission data is compressed and output only when the transfer speed of the communication interface is lower than the predetermined speed and the compression ratio of the transmission data is higher than the predetermined value. Therefore, in addition to the above-described effects of the first and second embodiments, the third embodiment
As described above with respect to the embodiment, the effect that the effect of compression can be reliably obtained is also obtained.

Further, according to the present embodiment, the effect that the inspection of the compression ratio can be executed quickly and unnecessary data compression can be eliminated can be obtained.

That is, as described above with reference to the third embodiment, when all of the transmission data is actually compressed,
While accurate compression ratios can be reliably obtained, since all of the transmission data is compressed once, it takes time and the compressed data may be wasted.

On the other hand, according to the present embodiment, the compression ratio is predicted by a simple method.
0 can be reduced, and quick processing can be secured.

The specific example shown in FIG. 9 corresponds to a specific example in which “compression ratio inspection means 18” is added to the configuration example of the second embodiment shown in FIG. However, the present invention is not limited to this. That is, it is needless to say that the same effect can be obtained by adding the "compression ratio inspection means 18" to the configuration example described above with reference to FIG. 1 as the first embodiment of the present invention.

(Fifth Embodiment) The first to fourth embodiments have been described.
As described in the embodiment, the data compression control device according to the present invention can appropriately control the compression / non-compression of transmission data according to the transfer speed of the communication interface and the like, and can improve the processing efficiency of the entire process. .

The data compression control device according to the present invention can be realized, for example, as hardware such as a dedicated integrated circuit semiconductor chip or a semiconductor chip array.

Further, the data compression control device according to the present invention is a device having a CPU (central processing unit) and a memory.
Can also be realized by operating.

The data compression control device implemented as described above is mounted on various devices having a communication interface to achieve a predetermined effect.

Hereinafter, as a fifth embodiment of the present invention,
A print information forming apparatus to which the data compression control device of the present invention is applied will be described.

FIG. 11 is a block diagram showing a schematic configuration of a printing system employing the print information forming apparatus according to the present embodiment. That is, the printing system shown in the figure has a configuration in which the host device 100 and the inkjet printer 300 are connected via the communication interface. The host device 100 includes the print information forming apparatus 160 of the present invention.
And a communication interface 120 are provided. The print information forming device 160 includes a print data generation unit 150 and any of the data compression control devices 10A to 10E (compression control units) described above with respect to the first to fourth embodiments. In the present specification, software corresponding to the print data generation unit 150 is referred to as a “print data generation module”.
Called.

The “image data” to be printed is input to the print data generation unit 150 from an application (not shown). Here, “image data” is, for example, RG
B24-bit digital data.

The print data generation section 150 has a role of converting the “image data” into “print data”. That is, “image data” represented by three elements of RGB (red, green, blue) and the like are converted into inks of respective colors (for example, cyan: C, magenta: M, yellow: Y, and black: K) used by the printer. The print data is converted into “print data” corresponding to dot arrangement information of four colors or six colors obtained by adding light cyan: LC and light magenta: LM.

FIG. 12 is a block diagram showing a specific example of the configuration of the print data generation unit 150. That is, the print data generation unit 150 includes the size conversion unit 150A and the color conversion unit 1
50B, a halftone processing unit 150C, and an interlace processing unit 150D.

The size conversion section 150A has a role of converting “image data” into a desired print size based on predetermined layout information. For example, “image data” consisting of RGB 24 bits is converted into a desired size.

The color conversion section 150B converts "image data" into data composed of printer color elements. That is,
The color correction is performed according to the characteristics of the ink colors and color development used by the printer, and the data is converted into ink color data. For example, R
“Image data” consisting of 24 bits of GB is converted to CMYK32
Convert to bit data.

The halftone processing section 150C executes binarization processing for expressing the density in a certain area based on the presence or absence of ink in dot units from the CMYK data after the color conversion. This halftone processing generates print data of CMYK. For example, CMYK 32-bit data obtained by color conversion is converted into CMYK 4-bit data.

The interlace processing section 150D converts the CMYK 4-bit data obtained by the halftone processing for interlace printing. Here, "interlace" means that printing is performed finely and at a pitch smaller than the arrangement pitch of the inkjet nozzles of the print head of the printer while shifting the print head in the main scanning direction and / or the sub-scanning direction. This is a printing method that can eliminate “unevenness” due to variations in the nozzle diameter of the head.

By the above processing, "image data" is converted into "print data".

The "print data" generated in this manner
Is sent to the data compression control devices 10A to 10E. The data compression control device has any of the configurations described above with respect to the first to fourth embodiments.
Based on the transfer speed of the print data and the compression ratio of the “print data” to be transmitted, the “print data” is compressed or uncompressed and transmitted to the printer 300 via the communication interface 120.

The print information forming apparatus 160 described above
It can be realized by software commonly called “printer driver”. That is, the print data generation unit 1
50 and the functions of the data compression control devices 10A to 10E can be realized in the host device 100 as a part of the “printer driver”. However, the data compression control devices 10A-
Needless to say, E may be realized in the host device 100 as software other than the “printer driver” or hardware such as a dedicated semiconductor integrated circuit.

On the other hand, the printer 300 includes an interface section 310, a receiving section 320, an interpretation restoring section 330, an image generating section 340, a printer engine 350, and a control section 36.
0, a panel unit 370, a status management unit 380, and a memory management unit 390.

The interface unit 330 receives print data from the host device 100 and transmits various status information such as a data request signal to the host device 100.

[0134] Receiving section 320 temporarily stores data transmitted from host device 100 as necessary. In the present invention, the receiving section 320 is not always necessary, and “image data” or the like received by the interface section 310 may be immediately sent to the interpretation restoring section 330.

The interpretation restoring unit 330 checks the type of the signal sent from the host device 100 and performs necessary data processing as needed. That is, the compression / non-compression state of the “print data” processed by the data compression control devices 10A to 10C of the host device 100 is checked, and if the print data is compressed, it is restored. Further, the interpretation restoring unit removes header information and footer information included in the received signal, and sends “print data” to the image generation unit 340.

The image generating section 340 is provided with the interpretation restoring section 33.
Based on the “print data” sent from “0”, a print image is generated, and the printer engine 350 is driven.

The printer engine 350 has a print head (not shown), its drive system, a paper feed mechanism, and the like, and executes printing based on the print image generated by the image generation unit 340.

The control section 360 controls each section of the printer 300, and the panel section 370 controls the printer 300.
The status management unit 380 controls the status of the printer 300, and displays the operation status and the like of the printer 300.
Controls a memory (not shown) for temporarily storing a print image.

The printing system of the present embodiment described above includes the data compression control devices 10A to 10E, and compresses data when the transfer speed of the communication interfaces 120 and 310 can be a "bottleneck" of the entire process. If not, the data is sent to the printer 300 uncompressed. In this way, when the communication interfaces 120 and 310 between the host device 100 and the printer 300 have a low transfer speed (or as the communication mode,
When a mode with a low transfer rate is set), the data is compressed to shorten the transfer time. On the other hand, when an interface (or communication mode) with a high transfer rate is used, the data is transmitted in an uncompressed state, and the loss accompanying the compression / decompression processing is eliminated.

In particular, when a high-speed communication interface is selected in a printer such as an ink jet printer or a laser printer, a printer engine involving mechanical operations often becomes a “bottleneck” in processing a printing process. In such a case, if the print data is transmitted to the printer without being compressed, the CP of the host device 100 may be transmitted.
It is also possible to greatly reduce the load of the compression processing in U.

Further, as described above with reference to the second embodiment, the compression rate of the "print data" to be transmitted to the printer is checked, and the compression process is performed only when efficient compression is possible. The load of the processing and the restoration processing in the printer 300 can be greatly reduced. If the load of the restoration processing in the printer 300 is reduced, the CPU of the printer can be efficiently used, and the printing processing can be speeded up.

The embodiment of the invention has been described with reference to the examples. However, the present invention is not limited to these specific examples.

For example, as a third embodiment, a printing system using an ink-jet printer has been described as a specific example.
In addition to this, various printers such as laser printers and LED printers can be used in the same manner, and similar various effects can be obtained.

Further, the data compression control device according to the present invention is not limited to a printing system. That is, the data compression control device of the present invention can be implemented by using predetermined hardware such as a semiconductor integrated circuit, or a CPU (central processing).
It can also be realized by operating a CPU with predetermined software in a device having a unit and a memory. These hardware and software are, for example, various computers such as personal computers, printers, scanners, digital cameras, various PDA (personal data assistance), game machines, and other various digital devices. hand,
By providing it as a part having a function of transmitting data via a communication interface, a predetermined effect is achieved.

Further, the colors of the inks used by the printer of the printing system are not limited to the four CMYK colors mentioned above as specific examples, but may be obtained by adding light colors such as light cyan and light magenta, and any other inks. Can be similarly used.

Further, in the case of a printing system, as long as it has a printer mechanism, it is not limited to a printer-dedicated machine, but may be a multifunction machine having other functions such as a copying machine and a facsimile machine. .

In addition, those skilled in the art can make various additions and changes within the scope of the present invention disclosed in this specification.

[0148]

The present invention is embodied in the form described above, and has the following effects.

First, according to the present invention, the transfer rate of the communication interface is determined, and if this can be a “bottleneck” in the entire process, the data is compressed and transmitted. By sending the data in the compressed state, the loss associated with the compression / decompression processing can be eliminated.

Further, according to the present invention, the compression effect of the transmission data is checked in advance, and the compressed data is transmitted only when the compression ratio equal to or more than the "predetermined value" is obtained. The compression can be applied to the transmission data only when the transmission data is obtained. As a result, the burden on the peripheral device receiving the data to restore the compressed data is also eliminated.

Further, according to the present invention, by predicting the compression ratio by a simple method, the load on the host device can be reduced and quick processing can be ensured.

As described in detail above, according to the present invention, the load on the CPU can be reduced by efficiently controlling the data compression / non-compression according to the transfer rate of the communication interface and the compression ratio of the transmission data. As a result, it is possible to provide a data compression control device, a data compression control method, a print information forming device, and a recording medium on which a program is recorded, which can ensure the smoothness of data communication.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing a schematic operation of the data compression control device 10A.

FIG. 3 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to a second embodiment of the present invention.

FIG. 4 is a flowchart illustrating a schematic operation of a data compression control device 10B according to a second embodiment.

FIG. 5 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to a third embodiment of the present invention.

FIG. 6 is a flowchart illustrating a schematic operation of a data compression control device 10C according to a third embodiment.

FIG. 7 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to a modification of the third embodiment of the present invention.

FIG. 8 is a flowchart showing a schematic operation of a data compression control device 10D of the present modified example.

FIG. 9 is a block diagram conceptually showing a configuration of a communication system including a data compression control device according to a fourth embodiment of the present invention.

FIG. 10 is a flowchart illustrating a schematic operation of a data compression control device 10E according to a fourth embodiment.

FIG. 11 is a block diagram illustrating a schematic configuration of a printing system employing a print information forming apparatus according to a fifth embodiment of the present invention.

FIG. 12 is a block diagram illustrating a specific example of a configuration of a print data generation unit 150.

FIG. 13 is a block diagram conceptually showing a printing system in which a host computer and a printer are connected.

[Explanation of symbols]

10A, 10B, 10C Data compression control device 11 Storage means 12 Route selection means 13 Selection information storage means 14 Compression means (compression module) 15 Storage means 16 Transfer speed determination means 18 Compression ratio inspection means 100 Host device 110 Control unit 114 Compression unit Reference Signs List 120 communication interface 150 print data generation unit (print data generation module) 160 print information forming device 200 peripheral device 210 communication interface 220 restoration unit 250 printer engine 300 printer 310 communication interface 320 reception unit 330 interpretation restoration unit 340 image generation unit 350 printer engine 365 control unit 370 panel unit 387 status management unit 390 memory management unit

Claims (12)

[Claims] 1. A data compression control device for controlling compression processing of data to be transmitted, comprising: compression means for compressing data; and path selection means for selecting a processing path for data to be transmitted. The data compression control device, wherein the path selection means determines whether or not data to be transmitted is compressed by the compression means according to a physical or logical type of a communication interface for transmitting data. . 2. The data compression control device according to claim 1, wherein the determination of the physical or logical type of the communication interface is made when the communication interface is connected to the communication interface. 3. The data compression control device according to claim 1, wherein the physical or logical type of said communication interface is determined each time data is transmitted. 4. A compression rate checking means for checking a compression rate of data to be transmitted by said compression means, wherein said path selecting means determines whether or not data to be transmitted is compressed by said compression means. Is determined according to the physical or logical type of the communication interface that transmits the data, and only when the compression ratio checked by the compression ratio checking unit is higher than a predetermined value, the data to be transmitted is compressed by the compression unit. And determining to output by compressing.
3. The data compression control device according to any one of 3. 5. A first storage means for storing the data to be transmitted in an uncompressed state, and a second storage means for storing data obtained by compressing the data to be transmitted by the compression means. And the compression ratio checking unit compares the uncompressed data stored in the first storage unit with the compressed data stored in the second storage unit. Checking the compression ratio, and when it is determined that the data to be transmitted is to be compressed and output, the path selecting means supplies the compressed data stored in the second storage means to the interface. When it is determined that data to be transmitted is not compressed and output, the uncompressed data stored in the first storage means is supplied to the interface. Motomeko 4 data compression controller according. 6. The compression ratio inspecting unit predicts the compression ratio without using data obtained by compressing the data to be transmitted by the compression unit. Data compression control unit. 7. The communication apparatus according to claim 7, wherein said path selecting means determines that data to be transmitted is not compressed when a physical or logical type of said communication interface is a type having a high transfer rate. Item 1
7. The data compression control device according to any one of items 1 to 6. 8. A data compression control method for controlling compression processing of data to be transmitted, wherein whether to compress data to be transmitted is determined according to a physical or logical type of a communication interface for transmitting the data. A data compression control method characterized in that the data compression control method is determined in accordance with the above. 9. When the physical or logical type of the communication interface is a type having a high transfer rate,
9. The data compression control method according to claim 8, wherein it is determined that the data to be transmitted is not compressed. 10. A print information forming apparatus for forming print information of an image to be printed, comprising: a print data generating unit for inputting image data to generate print data; and the print data generated by the print data generating unit. A compression control unit for controlling data compression processing, the compression control unit comprising: compression means for compressing print data; and path selection means for selecting a processing path for print data to be transmitted, The print information, wherein the path selection means determines whether or not the print data to be transmitted is compressed by the compression means, according to the physical or logical type of the communication interface for transmitting the print data. Forming equipment. 11. A print information forming apparatus for forming print information of an image to be printed, a printing apparatus for forming a predetermined image on a print medium by using the print information generated by the print information forming apparatus,
A print data forming unit that inputs image data to generate print data; and a compression that controls a compression process of the print data generated by the print data generating unit. A compression unit for compressing the print data; and a path selection unit for selecting a processing path for the print data to be transmitted, wherein the path selection unit transmits the print data. Whether to compress print data to be compressed by the compression unit is determined according to the physical or logical type of a communication interface that transmits print data, and the printing apparatus sends the print data from the print image forming apparatus. Receiving the print data and, if the print data is compressed, decompressing the print data to form a predetermined image on a print medium. Stem. 12. A computer-readable recording medium storing a program for controlling a compression process of data to be transmitted, the program comprising a compression module for compressing data to be transmitted, and a data to be transmitted. And determining whether the data is to be compressed and output by the compression module in accordance with the physical or logical type of the communication interface for transmitting data.