JPH06164651A - Image data transmitter - Google Patents

Abstract

PURPOSE:To provide an image data transmitter which reduces communication time in the case of transmitting image data via a network and reduces communication loads on the network. CONSTITUTION:This device is provided with a storage means 1 for storing image data, data amount detecting means 2 for detecting the data amount of image data stored in this storage means 1, data compressing means 3 for compressing the image data, transmitting means 4 for transmitting compressed or noncompressed data to a network 11, communicated amount monitoring means 5 for monitoring the communicated amount of data on the network, and image data compression judging means 6 for deciding whether the image data to be transmitted by the transmitting means 4 are compressed or not based on the image data amount provided from the data amount detecting means 2 and the communicated data amount provided from the communicated amount monitoring means 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image data transmitting apparatus connected to a local area network (hereinafter referred to as LAN).

[0002]

2. Description of the Related Art In recent years, image processing apparatuses such as printers, digital copiers, and facsimiles have passed image data obtained by converting code data into bit image data, read image data read by a scanner, and public lines. It has an image transmitting means for transmitting the transmitted image data to a network such as a LAN. The image data transmitted by these image processing devices to the network has a huge amount of data, and the amount of traffic on the network at the time of transmission of these data greatly increases. At this time, since the communication capacity on the network is reduced, the mixture with the image data communication on the LAN is a serious problem for other network users who are communicating data other than the image data.

Therefore, conventionally, the image data is converted into CCITT.
Recommendation T. 4 and T.S. It was transmitted on the network after being compressed by the encoding compression conforming to the standard No. 6. However, even if the amount of data to be transmitted on the network can be reduced by compressing the data in this way, there is a disadvantage that the time spent for the data compression and expansion is increased.

As a method for solving these problems, there is a method disclosed in Japanese Patent Laid-Open No. 2-143762. This is to detect the collision detection signal on the network to monitor the communication load condition of the network, and when the load exceeds a reference value, compress the image data and send it out on the network. The data amount is reduced and the image data is directly transmitted when the amount is less than the reference value.

[0005]

However, in the image data transmission method disclosed in Japanese Patent Laid-Open No. 2-143762, image data is transmitted without being compressed when the communication load on the network is small. Therefore, if the amount of image data to be transmitted at this time is large, the communication load on the network will increase,
It does not reduce the communication load on the network. That is, such an inconvenience occurs because the amount of image data to be transmitted is not considered as a parameter of the criterion for determining whether or not compression is possible.

Further, since the sum of the compression time and the transmission time of the image data and the decompression time of the compressed data at the destination terminal is not considered to have a correlation with the data amount of the target image, the image There is also a problem that the data communication time is not properly reduced. Therefore, it is an object of the present invention to eliminate the above-mentioned problems, and to provide an image data transmitting apparatus that realizes reduction of communication time when transmitting image data via a network and reduction of communication load on the network. And

[0007]

In order to achieve the above object, the present invention comprises a storage means for storing image data, and a data amount detection means for detecting the data amount of the image data stored in the storage means. A data compression means for compressing image data, a transmission means for transmitting the compressed or uncompressed data to a network, a communication amount monitoring means for monitoring the data communication amount on the network, and a communication amount monitoring means. An image data compression determination unit that determines whether to compress the image data to be transmitted by the transmission unit based on the image data amount and the data communication amount obtained by the communication monitoring unit is provided.

[0008]

According to the present invention, the communication amount monitoring means monitors the communication amount on the network, and the data amount detecting means detects the data amount of the image data to be transmitted. Then, based on the communication amount and the data amount obtained from them, the image data compression determination unit determines whether to transmit the image data to be transmitted stored in the storage unit after compressing it or transmitting it as uncompressed (raw data). To do.
Based on this determination result, it is determined whether or not to activate the data compression unit when transmitting the image data to be transmitted by the transmission unit.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 shows the basic configuration of an embodiment of the present invention.
The present invention compresses image data by a storage means 1 such as a hard disk for storing digital image data input by an image reading device, a facsimile receiving device or the like (not shown), and a method such as CCITT recommended group 3 or group 4. Data compression means 3, transmission means 4 for transmitting the image data stored in the storage means 1 or the compressed image data compressed by the data compression means 3 to a network 11 such as a LAN, and communication for monitoring the amount of communication on the network. It comprises a quantity monitoring means 5 and a central processing unit (hereinafter referred to as a CPU) 7, and these means are connected to a system bus 15 so that data can be exchanged with each other.

Further, the CPU 7 performs various controls of this apparatus. As a part of these various controls, the data amount detecting means 2 for counting the data amount of the image data stored in the storage means 1 in byte units, and communication. Image data compression for determining whether to compress the image data by the data compression unit 3 when transmitting the image data to the network 11 based on the communication amount obtained from the amount monitoring unit 5 and the image data amount obtained from the data amount detection unit 2. It has a judging means 6.

The data amount detecting means 2 operates under the control of an operating system for starting various control software on the CPU 7, and uses a data amount counting means provided by a file system or the like. The transmission means 4 is composed of a transceiver 9 and a communication control means 8 for controlling the transceiver 9. Using the communication amount detection signal 10 detected from the transceiver 9, the communication amount monitoring means 5 monitors the communication amount on the network 11 per unit time.

FIG. 2 shows the communication amount monitoring means 5 in more detail. The communication amount monitoring means 5 receives the communication amount detection signal 10 and the system clock 13 of this apparatus, which are sent from the transceiver 9 as needed, and outputs the communication amount 14 on the network 11 per unit time. In this embodiment, a carrier signal detected by a carrier sense circuit (not shown) in the transceiver 9 is used as the communication amount detection signal 10. This and the clock 13
The logical product of is counted by the counter 20, and the count value is held in the flip-flop 21 by the pulse generated by the timer counter 22 every unit time. In the figure,
Although the flip-flop 21 is treated as a single one for simplification of description, it is actually necessary to prepare a quantity corresponding to the bit width transmitted from the counter 20.

With such a circuit configuration, it is possible to detect the communication amount 14 on the network 11 per unit time by counting the carriers per unit time flowing on the network 11. By monitoring this, the communication load on the network 11 at the present time can be measured. Next, when transmitting image data on the network 11, a criterion for determining whether or not image compression is performed will be described.

FIG. 3 is a graph showing the principle of deriving this criterion. In FIG. 3, the horizontal axis represents the data amount of the image data to be transmitted detected by the data amount detecting means 2,
The vertical axis represents the time until the transmission image data is received by another terminal 12 (shown in FIG. 1) connected to the network 11. The graph a in the figure indicates that when the image data is transmitted to the network 11 without being compressed, the other terminal 12
It represents the average time to be received by. The graph a at this time is represented by y = func1 (x). Similarly, the graph b represents the average time when the same image data is compressed. The graph b at this time is represented by y = func2 (x). Here, it is assumed that the data compression unit 3 compresses the image data amount to about 1/3 on average. In reality, compression methods such as the MH, MR, and MMR methods are methods in which the compression rate varies depending on the type of image data, but here, as a result of measuring the compression rate in a specific image format, it is about 1/3. The case of being compressed is b. From this figure, it can be seen that the average time required for communication proportionally increases as the amount of data increases in both graphs a and b.

At this time, the graph of b only represents the communication time required for transmitting the compressed image data to the other terminal 12 via the network 11. It is necessary to consider the time required to compress the data and the time required to decompress the compressed image data when the other terminal 12 receives the image data. Therefore, the time required for these compression / decompression is shown in graph b.
What is reflected in FIG. c is an addition of the overhead amount ov to the graph b when the data compression unit 3 and the decompression unit (not shown) in the other terminal 12 are executed. Accordingly, the graph c represents the communication time when the compressed image data is used. The graph c at this time is assumed to be represented by y = func3 (x) = func2 (x) + ov.

At this time, consider an intersection (t, func1 (t)) between the graph a and the graph c. This intersection indicates that when the data amount is t, the time required until the other terminal 12 finishes receiving is the same whether the image data is transmitted as it is or is compressed and transmitted. That is, t is compressed / compressed when transmitted.
This is the amount of data that becomes equal to the communication time when transmitting without compression because the overhead ov required for the decompression operation is added to b. Therefore, when the amount of data is smaller than t, the communication time is shorter when the image data is transmitted without compression than when the image data is transmitted after compression, and vice versa when the amount of data is larger than t. I understand.

In such a situation, the network 1
Consider the communication amount 14 per unit time on 1. When the communication load on the network 11 is high, the communication load is further increased when a large amount of image data is transmitted from this apparatus, which is not preferable. Therefore, depending on the size of the communication amount 14 per unit time on the network 11. It is necessary to take measures to prevent the communication load when transmitting image data from exceeding a certain standard value. Since the communication load amount that increases when transmitting image data is proportional to the data amount of image data, it is also proportional to the time required to flow the data amount on the network 11, that is, the communication time.

Therefore, in order to keep the communication amount 14 per unit time on the network 11 below a certain specific communication load, it is necessary to provide an allowable communication time th and transmit a data amount that does not exceed the allowable communication time th. is there. This reference value th
Is the amount of communication 14 per unit time on the network 11.
It is a threshold value determined by, and it fluctuates depending on the amount of communication. That is, when the communication amount 14 is small, image data can be transmitted for a relatively long time as in th1 of FIG. 3, and when the communication amount 14 is large, th2.
As described above, the image data transmission needs to be completed in a short time.

Next, when the permissible communication time calculated from the communication amount 14 per unit time on the network 11 is th1, the image data to be transmitted depends on the size of the image data obtained by the data amount detecting means 2. The conditions for determining whether or not to compress will be described. When the data amount D is smaller than t, that is, in the case of A1 in FIG. 3, func1
Both (D) and func2 (D) are below th1.

Therefore, the communication load on the network 11 is within the allowable range because the allowable communication time th1 is less than the transmission of either compressed or non-compressed data. However, the time from transmitting the compressed data to receiving the image data at the other terminal 12 and ending the expansion is func3 (D),
Since func1 (D) <func3 (D), it can be understood that when the data amount D is smaller than t, it is possible to transmit to the other terminal 12 more efficiently in time by transmitting without compression.

When the data amount D is larger than t, and within the range of M1 in FIG. 3, the allowable communication time th1 is not exceeded even if the data is transmitted without compression (func1 (D) <th1), but f
Since unc3 (D) <func1 (D), it is understood that it is more efficient in terms of time to transmit the compressed data. B1,
Similarly, in the range of C1, it is more efficient to compress and transmit. However, in the range of C1, the allowable communication time th1 is exceeded, but in this case, the situation occurs when the user of this device wants to perform image communication even if the communication load of the network 11 exceeds the allowable range. It is necessary to take measures such as issuing a warning to the user before starting image transmission.

Next, consider a case where the allowable communication time obtained from the communication amount 14 per unit time on the network 11 is th2. In this case, it means image transmission when the communication load on the network 11 is considerably high. Func1 (D) when the amount of data D to be transmitted is smaller than t
In the case of <th2 (range A2 in FIG. 3), it is more time-efficient to send uncompressed image data (func1
Since (D) <func3 (D), and the communication load of the network 11 is also within the allowable range, it is understood that it is better to transmit without compression.

When func1 (D) <th2 (range M1 in FIG. 3), func1 (D) <func3 (D)
Therefore, it is more time efficient to send it uncompressed,
If uncompressed data is transmitted, there is a problem because the communication load of the network 11 also exceeds the allowable range. In this case, fun
Since c2 (D) <th2, when transmitting the compressed data, the allowable range of the communication load is not exceeded, so the image data is compressed and transmitted. Similarly, B2, C
In the range of 2, the image data is compressed and transmitted.
However, as in the case of C1, the allowable communication time th2 is exceeded in the case of C2 as well, so that it is necessary to take measures such as issuing a warning to the user before starting image transmission.

The image data compression determination means 6 performs image data compression determination using the above-described image data compression determination principle. The image data compression determination means 6 is realized by software in the CPU 7, and this flowchart is shown in FIG. However, t and func1 shown in FIG.
A value such as (x) is obtained in advance when the software is installed, and is stored in the storage means 1 or the like. At the time of image data compression determination, this value is read out and used as needed.

In FIG. 4, first, the data amount D obtained from the data amount detecting means 2 and the allowable communication time th obtained from the communication amount per unit time 14 of the network 11 obtained by the communication amount monitoring means 5 are acquired. (S1, S2). Then, the data amount D is compared with T using the value T stored in the storage means 1 or the like by previously obtaining the value of t in FIG. 3 (S
3). When D <T, func1 (D) is further compared with the allowable communication time th (S4).

If func1 (D) <th, it is determined that the image data is to be transmitted without being compressed, and the image data stored in the storage means 1 is sent to the transmission means 4 for data transmission (S5). When D ≧ T (S3), and func1
If (D) ≧ th (S4), it is determined that the data is compressed before transmission, and the data compression unit 3 is activated to compress the image data stored in the storage unit 1 (S6). Then, the compressed image data is sent to the transmission means 4 and data is transmitted (S5).

By performing such processing in the image data compression determination means 6, it is possible to appropriately determine whether or not to compress the image data according to the communication amount on the network 11 and the data amount of the image data to be transmitted. It becomes possible to do. Further, in the present embodiment, the parameters such as T and func1 (x) are stored in the storage means 1 and used, but a method of separately storing them in a read only memory (ROM) or the like, and these parameters are necessary. It is obvious that the operation of the present invention operates without any problem even with the method of obtaining it by sequential calculation at the point of time.

Further, in this embodiment, the network 11
Although the carrier signal is used as the communication amount detection signal 10 in the above, it is obvious that the present invention is not limited to this, and a collision detection signal (collision signal) on the network 11 can be used.

[0029]

As described above, according to the present invention,
By appropriately determining the compression / non-compression of the transmission target image data based on the transmission target image data amount and the communication amount per unit time on the network, it is possible to perform image data communication without exceeding the allowable communication load on the network. Since the required time can be transmitted in the most efficient manner, it is possible to reduce the load on the network due to the flow of image data and to reduce the communication time required for image data communication.

[Brief description of drawings]

FIG. 1 shows a basic configuration diagram in an embodiment of the present invention.

FIG. 2 shows a more detailed block diagram of a communication amount monitoring means.

FIG. 3 is a graph showing the principle of determining whether or not image data compression is possible.

FIG. 4 is a control flowchart in image data compression determination means.

[Explanation of symbols]

1 memory means 2 data amount detecting means 3 data compressing means 4 transmitting means 5 communication amount monitoring means 6 image data compression determining means 7 CPU 8 communication control means 9 transceiver 10 communication amount detecting signal 11 network 12 other terminal 13 clock 14 per unit Communication amount 15 System bus 20 Counter 21 Flip-flop 22 Timer counter S1 to S6 Image data compression determination means Each step of algorithm

Claims (1)

[Claims] 1. A storage unit for storing image data, a data amount detection unit for detecting a data amount of the image data stored in the storage unit, a data compression unit for compressing image data, and a compression unit for a network. Alternatively, a transmitting unit for transmitting uncompressed data, a communication amount monitoring unit for monitoring the data communication amount on the network, the image data amount obtained by the communication amount monitoring unit, and the data communication amount obtained by the communication monitoring unit. And an image data compression determination unit that determines whether or not the image data to be transmitted is compressed by the transmission unit.