JPH0556278A - Coder and decoder and image processor - Google Patents

Abstract

PURPOSE:To continuously perform the coding or decoding of picture data having the capacity equal to or more than that of a buffer memory with one trigger at the time of performing the coding and decoding of the picture data through the buffer memory. CONSTITUTION:A means to surely provide the prescribed difference between both addresses so that a writing address 116 for writing a picture data on a buffer memory cannot pass a reading address 117 is provided, or a comparing means to arrange a counter corresponding to both the addresses and always compare these counter values so that the writing does not pass the reading is provided. Thus, it is not necessary to code and decode considering the writing speed and the reading speed on and from a buffer, and even when the coding and decoding of the picture data having the capacity equal to of more than that of the buffer memory are performed continuously, the event that another picture data are overwritten on the picture data not read yet and the part not written yet is read is not generated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image processing apparatus such as a facsimile machine, and more particularly to an encoding / decoding apparatus suitable for eliminating the need for line-by-line management.

[0002]

2. Description of the Related Art A conventional encoding / decoding device is an address control device for inputting image data for encoding, as disclosed in, for example, Japanese Patent Laid-Open Nos. 61-84164 and 61-242463. An address control device for outputting decoded data is built in, and the operation of encoding / decoding is controlled line by line and the reading speed is controlled based on the remaining amount of the memory being used. Also, for example, Japanese Patent Laid-Open No. Sho 5
In the prior art described in Japanese Patent Publication No. 9-1645, when the remaining amount of the buffer memory for storing image data at the time of encoding becomes small, the encoding operation is stopped and waits for the remaining amount of the buffer memory to recover.

[0003]

In the MH coding, the MR coding, and the MMR coding used in the facsimile machine or the like, the generated code amount changes at the frequency of the change point of the black and white binary image of the coding line. In the two-dimensional encoding, the generated code amount changes depending on the relationship between the position of the change point of the reference line and the position of the change point of the coding line. Generally, the code amount increases in an image that changes finely in black and white, and the code amount decreases in an image that does not change much. In the above-described image in which the amount of code increases, whether the processing is performed by a microcomputer or by hardware logic, the number of pixels that can be processed per unit time is reduced and the encoding speed is reduced. On the contrary, in an image with little change in black and white, the processing speed per unit time is high and the encoding speed is high. The same applies to the case of decoding. If the amount of code data to be decoded increases, the amount of image data that can be restored per unit time decreases, and if the amount of code data is small, the restoration speed increases.

A control device for controlling a conventional system checks whether or not image data to be encoded is set in an input port for each line at the time of encoding and receives a control command from the control device to perform encoding. Is working. Also,
The control device receives the coding end signal from the coding device for each line and controls the reading speed. That is, the system control device needs to exchange control signals with the encoding device and the image data input device on a line-by-line basis, which causes a problem of a large processing load. Further, even at the time of decoding, while the system control device monitors the processing operation and time of the device that receives the decoded data, a device that processes the decoded data while outputting the control signal to the decoding device in line units Have control. Therefore, there is a problem that the processing load of the system controller is large even during the decoding operation.

Due to the recent technological progress, the processing speed of the encoding / decoding device is improved, and the processing speed of the image data input / output device connected thereto is also improved. The processing load on the system control device has become excessive as the processing speed of these devices has increased. Moreover, as described above, since the number of pixels that can be processed per unit time of the encoding / decoding device differs depending on the black and white pattern of the image, the processing speed greatly varies. This causes an excessive processing load on the system control device and requires the use of an expensive high-performance machine as the system control device, and the entire system becomes large due to complicated control. There is.

An object of the present invention is to provide a small-sized encoding / decoding device and an image processing device capable of high-speed operation by controlling only the start / stop of encoding / decoding by the system controller. Especially.

[0007]

SUMMARY OF THE INVENTION The above object is to prevent a read address of a storage device from overtaking a write address in a coding device for reading and encoding image data written in a storage device for a buffer. It is achieved by providing means.

The above object can also be achieved by providing a means for prohibiting new image data from being overwritten on the data which has been written in the storage device and which has not been encoded yet.

The above object is also to provide means for reducing the encoding speed when the encoding speed is faster than the writing speed of the image data to the storage device and the difference between the write address and the read address becomes a predetermined value or more. It will be achieved.

The above object is also to provide means for switching the coding mode to the high speed mode when the coding speed is slower than the writing speed of the image data to the storage device and the difference between the write address and the read address becomes less than a predetermined value. It will be achieved.

The above-mentioned object is, in a decoding device which reads out the decoded restored image data written in the buffer storage device and outputs it to the image data output device, the write address of the storage device overtakes the read address. It is achieved by providing a means to prohibit.

The above-mentioned object is also to provide means for prohibiting the overwriting of new decoded data on the data written in the storage device and not yet output to the image data output device. It will be achieved.

The above object is also achieved by providing means for reducing the decoding speed when the decoding speed is faster than the output speed of the restored data to the image data output device.

The above object is also achieved by providing means for reducing the output speed when the output speed to the image data output device is faster than the decoding speed.

The above-mentioned object is a coding / decoding apparatus for compressing / decompressing image data having means for writing / reading image data, and at the time of coding, the coding operation is performed without overtaking the image data written in the storage device. This is achieved by providing encoding means.

[0016]

In the present invention, encoding / decoding is performed at the time of encoding / decoding.
Even if the read speed and the write speed of the storage device used as the buffer for the decoded data are unbalanced, it is prohibited to write on the data that has not been read yet, or the data that has not been written is read. Since it is simply prohibited, the system control device does not need to control the line unit and the processing load is reduced.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of an encoding / decoding device according to an embodiment of the present invention. The encoding / decoding device 1 includes a system bus I / F 2 for exchanging signals with the system control device, an encoding / decoding control unit 3 for controlling an encoding / decoding operation, and Via an encoding / decoding processing unit 5 for performing encoding / decoding, an image bus I / F4 for inputting image data for encoding and outputting image data after decoding, and an image bus I / F4. An image data storage device input / output management unit 6 for controlling input / output of image data is provided. The image data storage device input / output management unit 6, which is a feature of this embodiment, uses the signal line 102 to connect the image bus I / F 4
, And the signal line 101 is connected to the encoding / decoding control unit 3. The signal line 100 is a line connecting the encoding / decoding control unit 3 and the image bus I / F 4. Image bus I /
F4 is connected by a signal line 103 to an external storage device 7 and an image data input / output unit of an apparatus for inputting / outputting image data, such as a CCD scanner or a printer (none of which is shown).

The image data storage device input / output management unit 6 manages the storage state of the storage device 7 from the flow of the image data input to the storage device 7 and the image data read from the storage device 7, and performs encoding / decoding. A control signal for encoding / decoding is transmitted to the control unit 3 via the signal line 101. The basic method of the present embodiment shown in FIG. 1 will be described below with reference to FIG.

FIG. 2 shows an input / output management unit 6 for the image data storage device.
3 is a detailed configuration diagram of FIG. First, the case of encoding will be described. In order to store the image data to be encoded in the storage device 7 by using the data transfer function of the image bus I / F 4, the management unit 11 that manages the write address to the storage device 7 sends the write control signal to the signal line. It is given to the image bus I / F 4 through 102, and the image data is written to the storage device 7 through the image bus I / F 4. In order to read the image data from the storage device 7 for encoding, similarly, a control signal is issued from the management unit 12 that manages the read address from the storage device 7, and the image data is read. The read image data is transmitted to the encoding / decoding control unit 3 through the image bus I / F 4 and encoded.

If reading and writing are performed in the same fixed cycle, the storage capacity used by the storage device 7 is always constant and no special control is required. For example, if the input of the image data is set to the maximum time of the encoding time of one scanning line, the reading in synchronization with the image data input device is possible. However, this method is not efficient because the coding time is always fixed at the longest time even for a document whose image data is not fine. Therefore, conventionally, the control command from the system control unit is waited in units of one scanning line, and the encoding is performed while matching the input speed of the image data and the encoding speed.

FIG. 3 is a diagram showing reading and writing in the storage device 7. The image data temporarily stored for encoding is the write address management unit 11
According to the write address 116 output by the storage device 7
When read for writing, the read address 115 is used for reading. There is an address difference 117 between the two.

If the encoding is too fast for the input of image data, the address difference 117 disappears. If nothing is controlled here, the write address 116 will be overtaken by the read address 115, and an erroneous operation will occur in which the area where image data is not yet set is encoded. When the storage capacity of the storage device 7 is a delimiter which is a unit of the input image data, for example, less than one page, the image data of the portion exceeding the capacity is to go around the storage device 7 and overwrite the previous image data. Become. There is no problem if the image data of the portion to be overwritten is read and encoded before being overwritten. However, if the encoding is too slow, the write address 116 will overtake the read address 115 and the image cannot be encoded. A malfunction occurs that a data area is generated.

In order to prevent the above-mentioned malfunctions, reduce the control load of the system control device, and efficiently perform encoding with a storage device having a small capacity, in the present embodiment, the read address 115 is set to the signal line. The write address 116 is input to the address comparison unit 14 via 111, and the write address 116 is input to the address comparison unit 14 via the signal line 110. The comparison unit 14 generates the address difference 117. Then, the address difference 117 is input to the encoding / decoding operation mode determination unit 13 via the signal line 112. According to the flowchart shown in FIG. 4, the operation mode determination unit 13 delays the encoding when the address difference 117 is small, and shifts to the faster encoding mode when the address difference 117 is large. A control signal for instructing the mode change is output and transmitted to the encoding / decoding control unit 3 through the signal line 101. As a result, the above-described malfunction can be prevented, the control of the input speed to the image data input unit can be eliminated, and the system control can be simplified.

Next, the case of decoding will be described. In the case of decoding, what is written in the storage device 7 (FIG. 1) by the write address management unit 11 (FIG. 2) is the restored image data decoded by the encoding / decoding processing unit 5 and the read address. The data read by the management unit 12 is the restored image data to be output by the output device. Also in this case, if nothing is controlled for reading and writing, and if the decoding is fast, the write address 116 (FIG. 3) goes around the storage device 7 and the read address 115.
Overwriting and rewriting (overwriting) on the restored image data that has not yet been output to the output device. Further, if the decryption is slow, an erroneous operation of outputting data that has not been restored occurs. Therefore, in the case of decoding, the encoding / decoding operation mode determination unit 13 executes control according to the flowchart shown in FIG. That is, as shown in this flowchart, the operation mode determination unit 13 delays the decoding when the address difference 117 is large, and the address difference 1
When 17 is small, the output of the restored image data is delayed in processing step 118, and the state is notified to the output device. Decoding also requires the above processing depending on the degree of image fineness, but unlike encoding, decoding is performed according to the coding mode of already coded data, thus speeding up decoding. I can't take the method. Therefore, the above step 118 is required. However, depending on the output device, this processing step 118 may not be acceptable. But,
If encoding is performed by using the encoding method of the above-described embodiment, a fatal delay can be avoided even in decoding, and the processing step 118 is unnecessary.

However, in facsimile communication, etc.,
It is recommended that the coding modes may be different depending on the partner device, and thus the code data according to this embodiment is not always available. When the output delay is not allowed, if the received data is re-encoded according to the above-described encoding method and the data is used as an input for decoding, the process 119 shown in FIG. 5 can be omitted. In addition, this processing 119
In an acceptable system, no special re-encoding is required. Alternatively, if the output device that outputs the restored data is properly set so that the restoration is not delayed, the process 119 is unnecessary. These should be determined appropriately from the system construction design. In any case, in the case of decoding as well, like the case of encoding, malfunction can be prevented by the operation of the decoding device alone. In addition, with a small number of restored data output buffers, it is possible to realize a simple and efficient decoding system without the need for decoding control in line units by the system control device.

FIG. 6 is a block diagram showing a second embodiment of the image data storage device input / output management unit 6 (FIG. 1). The address comparison unit 14 of the embodiment shown in FIG. 2 includes a read / write image data number counter 20 and a count value comparison unit 2 of the counter 20.
1 and a signal line 120 connecting them. Then, the comparison result of the comparison unit 21 is transmitted to the encoding / decoding operation mode determination unit 22 through the signal line 121, as in the embodiment of FIG. The read / write image data number counter 20 obtains the read image data number 125 shown in FIG. 7 from the address of the read image data transmitted through the signal line 123, and writes the write image data from the address of the write image data transmitted through the signal line 122. Equation 126 is obtained. Each of them is input to the count value comparison unit 21 through the signal line 120 and compared, and the count difference 12
7 is required. This count difference 127 is calculated by the signal line 12
1 is transmitted to the encoding / decoding operation mode determination unit 22.

At the time of encoding, the operation mode determination unit 22 determines the operation mode according to the flowchart shown in FIG. 8, and delays the encoding or speeds up the encoding according to the count difference similarly to the processing shown in FIG. The control signal for instructing the change to the encoding mode is output and transmitted to the encoding / decoding control unit 3 through the signal line 101.

At the time of decoding, the operation mode is determined according to the flow chart shown in FIG. 9 by the count difference 127, and the decoding is delayed or the output of the restored image data is performed in the process 128 as in the process shown in FIG. It is delayed and the state is notified to the output device. The process 129 shown in FIG.
As with the processing 119 described with reference to FIG. 5, the necessity thereof is determined depending on the system configuration.

Next, a third embodiment of the image data input / output management unit 6 will be described with reference to FIG. In this embodiment, the address comparison unit 14 in FIG.
This is replaced with the address generation unit 31 which is late, the address overtaking determination unit 32, and the signal line 130 which connects them. Here, the processing contents of each of the configuration units 31 and 32 will be described with reference to FIG.

In the address generator 31 that advances / lags the write address, from the address 134 transmitted through the signal line 132 to the address 13 that retards to the address.
5 and the preceding address 136 are generated. Address 1
35 is logically obtained from the determination threshold Ms (encoding deceleration instruction threshold address difference, restored data output deceleration threshold address difference) determined by the processing shown in the flowcharts of FIGS. 4 and 5, and the write address 116. Corresponds to the address. Similarly, the address 136 is an address obtained from the write address 116, the capacity Mo of the storage device 7, and the threshold value Md (the threshold address difference for changing to the high-speed encoding mode, the threshold address difference for decoding deceleration instruction). Equivalent to. During the encoding operation, the address overtaking determination unit 32
Read address 13 transmitted through the signal line 133
7 passes the address 135, the overtaking signal is encoded and decoded through the signal line 131.
Transmit to 3. The address 136 goes around and the address 13
Similarly, when passing 7, the overtaking signal is output to the determination unit 33. The determination unit 33 performs the same control as the processing in FIG. 4 according to the flowchart shown in FIG. At the time of decoding, the same signal as in the case of encoding is transmitted to the determination unit 33, and the same control as the decoding control shown in FIG. 5 is performed according to the flowchart shown in FIG. Whether or not the process 139 shown in FIG. 13 is necessary is determined depending on the system configuration, like the process 119 described with reference to FIG.

Next, a fourth embodiment of the image data storage device input / output management unit 6 will be described with reference to FIG. In the present embodiment, the address comparison unit 14 in FIG. 2 is replaced with an address generation unit 40 that advances / lags the read address, an address overtaking determination unit 41, and a signal line 140 connecting these. Here, the processing contents of the constituent units 40 and 41 will be described with reference to FIG. The address generation unit 40 that advances / lags the read address generates the address 145 that advances to the address 144 and the address 146 that precedes the read address 144 transmitted by the signal line 143. The address 146 corresponds to an address logically obtained from the determination threshold Ms determined in the processing of FIGS. 4 and 5 and the write address 116.
Similarly, the address 145 is the write address 116.
And the address obtained from the capacity Mo of the storage device 7 and the threshold Md. During the encoding operation, in the address overtaking determination unit 41, when the address 146 overtakes the write address 147 transmitted through the signal line 142, or when the address 147 makes one round and overtakes the address 145, the overtaking signal is similarly output. , Through the signal line 141 to the encoding / decoding operation mode determination unit 42.
The determination unit 42 performs the same control as the processing of FIG. 4 according to the flowchart shown in FIG. At the time of decoding, the same signal as that at the time of encoding is transmitted to the determination unit 42, and
The same control as the decoding control shown in FIG. 5 is performed according to the flowchart shown in FIG. Whether or not the process 149 shown in FIG. 17 is necessary is determined depending on the system configuration, like the process 119 described with reference to FIG. Next, a fifth embodiment of the image data input / output management unit 6 will be described with reference to FIG.
In this embodiment, the count value comparison unit 21 and the signal line 1 in FIG.
20 is replaced with a counter 50 that advances / lags the write image data number counter, a count value overtaking determination unit 51, and signal lines 150, 151, and 152. Here, regarding the processing contents of each of the components 50 and 51,
This will be described with reference to FIG.

The counter 50, which advances / lags the write image data number counter, counts from the write image data count value 154 transmitted by the signal line 150 to the count value 155 that delays to the count value and the preceding count value 1
56 is generated. These values transmitted through the signal line 151 and the read image data number count value 157 transmitted through the signal line 152 are compared and determined by the count value overtaking determination unit 51. That is, the read number count value 1
57 overtakes count value 155 or count value 1
When the count value 156 is overtaken after one round of 57, the overtaking signal is output to the encoding / decoding operation mode determination unit 52 through the signal line 153. The count value 155 is logically obtained from the judgment threshold value Ns (encoded deceleration instruction threshold value count difference, restored data output deceleration threshold value difference) defined in the flowcharts of FIGS. 8 and 9 and the write count value 126. Corresponds to the count value. Similarly, the count value 156 is the same as the count value 126 and the storage device 7.
And a threshold value Nd (threshold count difference for changing to high-speed encoding mode, decoding deceleration instruction threshold count difference), which corresponds to a count value logically obtained. At the time of encoding, the determination unit 52 performs processing according to the flowchart shown in FIG. 20, and performs the same control as the encoding processing shown in FIG. At the time of decoding, the process is performed according to the flowchart shown in FIG. 21, and the same control as the decoding process shown in FIG. 9 is performed. Processing 15 shown in FIG. 21
Whether or not No. 9 is necessary is determined depending on the system configuration, like the process 129 of FIG.

Next, a sixth embodiment of the image data storage device input / output management unit 6 will be described with reference to FIG. In the embodiment of FIG. 18, the counter values are generated before and after the write image data number counter, but the same control can be realized by generating similar counter values before and after the read image data number counter. The embodiment shown in FIG. 22 realizes this method. That is, the read image data number counter precedes /
The slowing counter 60 replaces the counter 50 of FIG. 18, and the signal lines 160, 161, 162 are replaced by the signal line 1 respectively.
The counter value passing determination unit 61 corresponds to 50, 151 and 152, and corresponds to the same determination unit 51. In this embodiment, the state of each counter value corresponding to FIG. 19 is as shown in FIG. 23, and the count value overtaking determination unit 61 uses the signal line 1
The respective values obtained through 61 and 162 are compared and judged. When encoding, the count value overtaking determination unit 61 outputs the overtaking signal to the determination unit 62 when the count value 166 preceding the read count value 164 overtakes the write count value 167. When the count value 167 laps over the count value 165 which lags behind the count value 164, the overtaking signal is output to the encoding / decoding operation mode determination unit 62 through the signal line 163. The determination unit 62
Performs the same encoding control as in FIG. 20 according to the flowchart shown in FIG.

In the case of decoding, the same control as the decoding control described in FIG. 21 is realized according to the flowchart shown in FIG. As described with reference to FIG. 21, whether or not the process 169 in FIG. 25 is necessary is determined depending on the system configuration.

FIGS. 26, 28, 30, and 32 are embodiments in which the system is simplified because they are applied to a system which requests the restored data at a constant speed when the decoding is started at the time of decoding. .. Since the mode of decoding is determined by the code, it is not possible to perform decoding while changing the decoding mode to a mode capable of faster decoding, such as coding. Therefore, the encoding is performed by the encoding method shown in each of the above-described embodiments of the present invention, or the buffer of the storage device 7 can absorb the acceleration / deceleration of the speed in advance. In this case, it is not necessary to delay the output of the restored data because decoding cannot be added in time, and the configuration is simplified.

First, the embodiment shown in FIG. 26 will be described.
In the seventh embodiment, the address generation unit 40 that advances / lags the read address shown in FIG. 14 is simplified to be an address generation unit 70 that delays the read address. 175 is generated. The address overtaking determination unit 71 corresponds to the determination unit 41 in FIG. 14, and the signal lines 170, 171, 172, 173 are also the signal lines 140, 141, 142, 143 in FIG.
Corresponding to. The determination unit 71 uses the write address 176 of the restored data transmitted via the signal line 172 to the storage device 7.
However, when it overtakes the lagging address 175 generated by the generator 70 from the read address transmitted by the signal line 173, the overtaking signal is transmitted to the decoding operation mode determination unit 72 via the signal line 171. The decryption operation mode determination unit 72 performs a simplified process by removing the process 149 of FIG. 17 to control the decryption operation. In the configuration of FIG. 26, coded data needs to be input in advance in accordance with the decoding speed, but there is an advantage that internal processing at the time of decoding can be simplified. Even in this case, the decoding control for each line of the system control device is not necessary, and the advantage of executing the decoding with the other configuration of FIG. 14 is not changed.

FIG. 28 relates to the eighth embodiment of the present invention, and an address generation unit 70 which advances to the read address of FIG. 26.
Is replaced with an address generator 81 preceding the write address. That is, as shown in FIG. 29, the generation unit 81 generates an address 185 preceding the address 184 for writing the restored data transmitted by the signal line 182 to the storage device 7. The address 185 and the signal line 18
The read address 186 transmitted by No. 3 is determined by the address passing determination unit 82, and when the address 185 makes a round and passes the address 186, the passing signal is transmitted to the decoding operation mode determination unit 83 through the signal line 181. The determination unit 83 controls the decoding operation by a simplified process in which the process 139 is removed from the flowchart shown in FIG. Also in this case, with the configuration more simplified than that of FIG. 10, if the input of the code data is restricted as described in FIG. 26, the output speed of the decoded data does not fall below the request of the output device, The decryption system can be configured while the control on the system side remains simplified.

FIG. 30 relates to the ninth embodiment of the present invention, and similarly to the description of FIGS. 26 and 28, the configuration of FIG. 18 at the time of decoding is assumed on the assumption that the input of code data is restricted. It's simplified. That is, the counter 50 which advances / lags the write image data number counter in FIG. 18 is simplified as the counter 90 which precedes the write image data number counter. In addition, the count value overtaking determination unit 91 corresponds to the count value overtaking determination unit 51 of FIG.
0, 191, 192, 193 are signal lines 150, 15 respectively
1, 152, 153. The counter 90 generates a counter value 195 preceding the counter value from the write image data number counter value 194 shown in FIG. 31 transmitted through the signal line 190. The count value overtaking determination unit 91 compares this value 195 with the read output counter value 196 input through the signal line 192. When the counter value 195 exceeds the counter value 196, the overtaking signal is output through the signal line 193. Output to the decoding operation mode determination unit 92. The determination unit 92 controls the decoding process by a simplified process in which the process 159 of the flowchart of FIG. 21 is deleted. Also in this case, the effect of simplifying the system control as described with reference to FIG. 18 is maintained.

FIG. 32 relates to a tenth embodiment of the present invention,
Instead of the counter 90 preceding the write image data number counter in FIG. 30, a counter 200 that delays the read image data number counter is used, and the same control is realized. The count value overtaking determination unit 201 corresponds to the determination unit 91. Each signal line 300, 301, 302,
303 corresponds to the signal lines 190, 191, 192 and 193, respectively. In the configuration shown in FIG. 30, the counter preceding the number of write image data is used to prevent the decoding from proceeding too much. In the present embodiment, the counter 200
A counter value 305 that is delayed from the read image data number counter value 304 shown in FIG. 33 input through the signal line 300 is generated, and this value 305 and the write image data number count value 306 transmitted through the signal line 302 are The count value is input to the overtaking determination unit 201 to prevent excessive progress of decoding. That is, the determination unit 201 determines that the count value 30
When 6 passes one round and passes the count value 305, the overtaking signal is transmitted to the decoding operation mode determination unit 202 through the signal line 303. The determination unit 202 controls the decoding process by a simplified process in which the process 129 shown in FIG. 25 is deleted, and prevents the decoding from progressing too much. As described in the description of FIG. 22, in this case also, the simplification of the processing on the system control side is maintained, and with the effect of simplification with this device itself,
The decoding function can be realized with a simpler configuration.

Next, a system configuration example using the image data storage device input / output management unit 6 according to each of the above-described embodiments will be described. FIG. 34 is a block diagram of an encoding device using the diagram data storage device input / output management unit 6. The coding / decoding control unit 3 and the coding / decoding processing unit 5 in FIG. 1 are replaced by a coding control unit 481 and a coding processing unit 482, respectively. For example, the encoding device 480 is built in a filing device or the like attached to a database or the like used to store a document image or the like. As a system for reading image data, there is a system in which a plurality of output devices are prepared for one database and each decoding device outputs the data. FIG. 35 shows an embodiment in which the encoding device 480 is applied to a filing system. The reference numeral 500 in FIG. 35 denotes the document encoding system main body. The manuscript is code data input / output I
If a storage device that files through / O505 is directly connected, it is directly connected to the storage device, but if the storage device is remote, it is input to the storage device via a communication device. The device 500 will be described below along the flow of signals.

A control signal is transmitted from the control device 504 to the reading controller 506 through the signal line 604, and the controller 506 operates the reading drive system 508 through the signal line 605 according to this control signal, and the sensor 502.
Control the timing of. As a result, the image data of the original 509 is captured by the sensor 502 through the reading optical system 501. The captured image data is
The image processing device 503 performs image processing such as edge enhancement, dithering, and error diffusion processing. These processes are controlled by a control signal from the control device 504 transmitted through the signal line 602. Then, the image signal is input to the encoding device 480 through the signal line 601 using the storage device 507 as a buffer, and after being encoded here,
It is transmitted to the external storage device through the signal line 604 and the I / O 505. In this system, the encoding device 507 is
Since the speed control is independently performed according to the usage state of the storage device 507, it is possible to input the image data at a constant speed. Further, since the control load of the control device 504 is significantly reduced as compared with the conventional one, a high speed encoding system can be realized.

Next, the decoding system will be described.
FIG. 36 is a block diagram of a decoding device using the image data storage device input / output management unit 6 described above. The encoding / decoding control unit 3 of FIG. 1 is replaced with a decoding control unit 491, and the encoding / decoding processing unit 5 is replaced with a decoding process 492 to configure a decoding device. FIG. 37 shows an embodiment of the decoding device when applied to a printer or a display device for outputting an image. What is denoted by reference numeral 580 in FIG. 37 is
This is the main body of the original decryption system. Hereinafter, description will be given along the flow of signals.

Code data is input from a storage device such as a filing device through a signal line 680 and an I / O unit 581. The control signal output from the control device 582 is supplied to the input controller 585 through the signal line 681.
In addition, it is transmitted to the decoding device 490 and the output device I / F 583 through the signal line 684 and controls these. The coded data transmitted to the decoding device 490 is restored by the decoding device 490, and is output to the output device I / F 583 through the signal line 682 while synchronizing with the output device such as a printer using the storage device 585 as a buffer. .. After that, the restored image data is output from the I / F 583 to the printer, the display device or the like through the signal line 683.

If the output device is a laser beam printer, image data at a constant speed is required. Therefore, the input of the code data is limited, and FIG. 26, FIG. 28, FIG. 30, FIG.
The use of the decoding device shown in FIG. 2 allows a more simplified system. For a thermal printer, a display, or the like that does not necessarily require input of data at a constant speed, it is possible to provide a system that outputs image data at higher speed without limiting the input code data. However, in any case, compared with the conventional decoding system, the control load of the control device 582 is significantly reduced, so that the system can output the restored data at high speed.

FIG. 38 shows an embodiment in which the coding / decoding apparatus 1 shown in FIG. 1 is applied to a facsimile apparatus which requires both coding and decoding functions. First, among the functions of the facsimile device 550, the functions from encoding to image transmission will be described. An image processing unit 55 that reads an original image with a reading system 551 including a reading sensor such as a CCD image sensor or a contact sensor and performs processing such as edge enhancement, dithering, and error diffusion through a signal line 651.
The image signal is transmitted to 2. Next, using the storage device 557 as a buffer, the image signal is transmitted to the encoding / decoding device 1 through the signal line 652, and is encoded here. The coded data is temporarily stored in the code storage device 554 through the signal line 653 and then output to the communication line through the communication I / F 556 including a modem or an ISDN I / F, or the code storage device 554 is stored in the code storage device 554. It is output to the communication line through the direct communication I / F 556 without going through. The flow of these processes is from the control device 553 to the signal line 655.
It is controlled by a control signal transmitted through 653. In addition, a peripheral device 555 including a man-machine I / F, etc.
Is also controlled by the control device 553.

Next, the decoding operation will be described. The signal received through the communication line is temporarily stored in the code storage device 554 through the signal line 653 and then transmitted to the coding / decoding device 1 or directly to the coding / decoding device 1. Thereafter, the storage device 557 is used as a decoding buffer for decoding and the recording I / F 55 is supplied through the signal line 654.
8 and the restored data is transmitted to the recording system 559 through the signal line 655 in synchronization with the recording device (not shown). The operation from reception to recording is also controlled by the control device 553, and the processing proceeds efficiently.

Although the system having the code storage device 554 has been described here, even in the G3 facsimile and the G4 facsimile, the communication line speed is slower than the encoding and decoding speeds, and therefore the merit of the encoding / decoding device 1 is advantageous. In order to efficiently utilize the above, it is better to have this storage device 554 and match the speed. This allows
It is possible to improve man-machine characteristics such as reading a document quickly and shortening the time from the start to the end of recording. Even without the storage device 554, the load on the control device 553 is significantly reduced as compared with the conventional device, so that the firmware of the control device 553 can be reduced and the control device itself can be simplified. Even if only used, the facsimile apparatus can be sufficiently simplified.

According to the above-described embodiment, the encoding speed is controlled while the encoding / decoding device manages the use status of the storage buffer device for encoding, and the processing is advanced. On the system controller side,
After outputting the encoding start command, it is not necessary to intervene in the encoding process during operation. For this reason, for example, when reading an A4 size document at a line density in the sub-scanning direction of 7.7 lines / mm, control of at least 2300 times becomes unnecessary.

Furthermore, since the decoding process can be executed independently at the time of decoding as well, the control load of the system control device can be reduced as in the case of encoding. Further, when a system for encoding image data at high speed is configured by reducing the system control load, it is not necessary to upgrade the control device, and the control load of the system control device becomes a bottleneck to limit the speedup. Will disappear. Similarly, even when configuring a high-speed decoding system, the neck of the control load can be eliminated, so that the decoding system can be configured at high speed.

Furthermore, in encoding, since the encoding mode is changed independently in the encoding / decoding apparatus of the present embodiment and the feedback control to the reading system is not necessary, a constant state independent of the encoding system is obtained. A simple control reading system for reading a document at a speed can be configured.

Also in the case of decoding, if the encoded image is encoded by the encoding apparatus according to the present embodiment, or if the input speed of the code is limited, when outputting the restored image, an output below the encoding speed is output. In the case of a device, when delaying a restored image to the output device, feedback control for instructing the output device to decelerate is unnecessary, and the output system control system can be greatly simplified.

Furthermore, according to this embodiment, since a high-speed manuscript input / output process can be performed with a simple system, an increase in apparatus cost can be avoided and a higher-speed manuscript input / output system can be constructed. The effect of shortening the waiting time for the manuscript of the manuscript is improved, and the man-machine property is improved.

[0053]

According to the present invention, when the encoding / decoding is performed via the buffer memory, the data written in the buffer is not overtaken and the data is not read from the buffer. Data can be continuously encoded / decoded by one trigger command, the processing speed can be increased, and the control load can be reduced.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram of an encoding / decoding device according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of an image data storage device input / output management unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of an address management method of an image data storage device input / output management unit of the first embodiment.

FIG. 4 is a flowchart showing an encoding procedure of an image data storage device input / output management unit of the first embodiment.

FIG. 5 is a flowchart showing a decoding procedure of the image data storage device input / output management unit of the first embodiment.

FIG. 6 is a configuration diagram of an image data storage device input / output management unit according to a second embodiment.

FIG. 7 is an explanatory diagram of a counter management method of the image data storage device input / output management unit according to the second embodiment.

FIG. 8 is a flowchart showing an encoding procedure of an image data storage device input / output management unit according to the second embodiment.

FIG. 9 is a flowchart showing a decoding procedure of the image data storage device input / output management unit according to the second embodiment.

FIG. 10 is a configuration diagram of an image data storage device input / output management unit according to a third embodiment.

FIG. 11 is an explanatory diagram of an address management method of an image data storage device input / output management unit according to the third embodiment.

FIG. 12 is a flowchart showing an encoding procedure of an image data storage device input / output management unit according to the third embodiment.

FIG. 13 is a flowchart showing a decoding procedure of the image data storage device input / output management unit according to the third embodiment.

FIG. 14 is a configuration diagram of an image data storage device input / output management unit according to a fourth embodiment.

FIG. 15 is an explanatory diagram of an address management method of the image data storage device input / output management unit according to the fourth embodiment.

FIG. 16 is a flowchart showing a coding procedure of an image data storage device input / output management unit according to the fourth embodiment.

FIG. 17 is a flowchart showing a decoding procedure of the image data storage device input / output management unit according to the fourth embodiment.

FIG. 18 is a configuration diagram of an image data storage device input / output management unit according to the fifth embodiment.

FIG. 19 is an explanatory diagram of a counter management method of the image data storage device input / output management unit according to the fifth embodiment.

FIG. 20 is a flowchart showing the encoding procedure of the image data storage device input / output management unit according to the fifth embodiment.

FIG. 21 is a flowchart showing a decoding procedure of the image data storage device input / output management unit according to the fifth embodiment.

FIG. 22 is a configuration diagram of an image data storage device input / output management unit according to the sixth embodiment.

FIG. 23 is an explanatory diagram of a counter management method of the image data storage device input / output management unit according to the sixth embodiment.

FIG. 24 is a flowchart showing the encoding procedure of the image data storage device input / output management unit according to the sixth embodiment.

FIG. 25 is a flowchart showing a decoding procedure of the image data storage device input / output management unit according to the sixth embodiment.

FIG. 26 is a configuration diagram of an image data storage device input / output management unit according to the seventh embodiment.

FIG. 27 is an explanatory diagram of an address management method of the image data storage device input / output management unit according to the seventh embodiment.

FIG. 28 is a configuration diagram of an image data storage device input / output management unit according to the eighth embodiment.

FIG. 29 is an explanatory diagram of an address management method of the image data storage device input / output management unit according to the eighth embodiment.

FIG. 30 is a configuration diagram of an image data storage device input / output management unit according to the ninth embodiment.

FIG. 31 is an explanatory diagram of a counter management method of the image data storage device input / output management unit according to the ninth embodiment.

FIG. 32 is a configuration diagram of an image data storage device input / output management unit according to the tenth embodiment.

FIG. 33 is an explanatory diagram of a counter management method of the image data storage device input / output management unit according to the tenth embodiment.

FIG. 34 is a configuration diagram of an encoding device according to an eleventh embodiment.

[Fig. 35] Fig. 35 is a configuration diagram of a filing device main body to which the encoding device according to the eleventh embodiment is applied.

[Fig. 36] Fig. 36 is a configuration diagram of a decoding device according to a twelfth embodiment.

FIG. 37 is a configuration diagram of an output device to which the decoding device according to the twelfth embodiment is applied.

FIG. 38 is a block diagram of a facsimile apparatus according to a thirteenth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Encoding / decoding device, 6 ... Image data storage device input / output management unit, 11 ... Storage device write address management unit, 1
2 ... Read address management unit from storage device, 14 ... Address comparison unit, 13, 22, 33, 42, 52, 62 ...
Encoding / decoding operation mode determination unit, 20 ... Read / write image data number counter, 21 ... Count value comparison unit, 31 ... Address passing determination unit that advances / lags the write address,
32 ... Address overtaking determination unit, 40 ... Address generation unit that advances / lags the read address, 41 ... Address overtaking determination unit, 50 ... Advances / writes to the write image data number counter
Counter that slows down, 51 ... Count overtaking determination unit, 60
... a counter that advances / lags the read image data number counter, 61 ... a count value passing judgment unit, 70 ... an address generation unit that delays to a read address, 71 ... an address passing judgment unit, 72, 83, 92, 202 ... decoding Decoding operation mode determination unit, 81 ... Address generation unit preceding write address, 82 ... Address passing determination unit, 90 ... Counter preceding write image data number counter, 91 ... Count value passing determination unit, 200 ... Read image data number Counter that advances to the counter, 201 ... Count value overtaking determination unit, 480 ... Encoding device, 490 ... Decoding device, 500
Document reading image data coding system, 550 Facsimile device, 580 Coded data decoding system

Claims (30)

[Claims] 1. An encoding device for reading and encoding image data written in a storage device for a buffer,
An encoding apparatus comprising means for prohibiting a read address of the storage device from overtaking a write address. 2. An encoding device for reading and encoding image data written in a storage device for a buffer,
An encoding apparatus comprising means for prohibiting new image data from being overwritten on data which has been written in the storage device and which has not been encoded yet. 3. An encoding device for reading and encoding image data written in a storage device for a buffer,
Coding is characterized in that the coding speed is faster than the writing speed of the image data to the storage device, and the coding speed is reduced when the difference between the write address and the read address exceeds a predetermined value. apparatus. 4. A coding device for reading and coding image data written in a storage device for a buffer,
Coding is characterized in that the coding speed is slower than the writing speed of the image data to the storage device, and means for switching the coding mode to the high speed mode when the difference between the write address and the read address becomes equal to or less than a predetermined value. apparatus. 5. A decoding device which reads out decoded restored image data written in a buffer storage device and outputs the decoded image data to an image data output device, and prohibits a write address of the storage device from overtaking a read address. A decoding device comprising means for performing. 6. A decoding device for reading decoded restored image data written in a buffer storage device and outputting the decoded restored image data to an image data output device, wherein the data written in the storage device is still an image. A decoding device comprising means for prohibiting new decrypted data from being overwritten on data that has not been output to the data output device. 7. A decoding device which reads out decoded restored image data written in a buffer storage device and outputs the decoded restored image data to an image data output device, wherein the decoding speed is restored data to the image data output device. Decoding device comprising means for reducing the decoding speed when the output speed is faster than 8. A decoding device for reading decoded restored image data written in a buffer storage device and outputting the decoded restored image data to an image data output device, the output speed to the image data output device being higher than the decoding speed. A decoding device comprising means for reducing the output speed when the output speed is high. 9. An encoding / decoding device for compressing / decompressing image data having a means for writing / reading image data, wherein the encoding operation is performed without overtaking the image data written in the storage device at the time of encoding. An encoding / decoding device comprising means. 10. The method according to claim 9, wherein when the image data is continuously encoded in a capacity equal to or more than the storage device, it is prohibited to pass the image data and encode the image data. An encoding / decoding device comprising means for prohibiting rewriting of new image data in the. 11. The coding / decoding apparatus according to claim 9, further comprising means for prohibiting output of data which has not been decoded from the decoded image data storage apparatus at the time of decoding. 12. The output device according to claim 9, wherein when the code data is continuously decoded in a capacity equal to or larger than the capacity of the decoding buffer storage device, output of data from the storage device to the output device is prohibited up to an undecoded area. The encoding / decoding device further comprises means for prohibiting writing the decoded data again on the decoded data that has not been output to the output device. 13. The prohibition means according to claim 10, wherein the prohibition means compares the address of the address control device that writes the image data in the storage device at the time of encoding with the address of the read address control device for encoding. An encoding / decoding device characterized by determining whether or not to perform. 14. The method according to claim 12, wherein the prohibiting means includes an address of an address control device that writes the decrypted data to a storage device during decryption and an address of a read address controller that outputs the decrypted data to an output device. And an encoding / decoding device for determining whether or not to prohibit. 15. The means for inhibiting according to claim 10, wherein the prohibiting means reads a number of image data written in a storage device at the time of encoding into a first counter and an encoding / decoding device for encoding. Second to count the number of data
The counter and the first and second areas within a range which does not pass over image data from the storage device and is not written again on the uncoded image data stored in the storage device.
An encoding / decoding device comprising means for ensuring that the difference between the counter values is always present. 16. The method according to claim 12, wherein the prohibiting means counts a first counter that counts the number of pieces of decoded data written in the storage device during decoding, and a number of data that is output from the storage device to the output device. Between the second counter and the second counter, the difference between the values of the first and second counters is within a range in which the decoded data is not overtaken and output from the storage device and is not rewritten on the unoutput decoded data stored in the storage device. An encoding / decoding device, characterized in that it is a means for always entering. 17. The means according to claim 10, wherein the prohibiting means generates an address which is separated by a certain distance before and after the address of the address control device for writing the image data in the storage device during encoding. A means for temporarily stopping the encoding process when the address of the encoding image data reading address control device has overtaken the decelerating address and the address of the address control device for writing the image data in the storage device are preceded. When the address circulates and overtakes the address of the encoding image data reading address control device, the encoding is changed to a mode with a short encoding speed time such as a non-compression mode code. Encoding / decoding device. 18. The means according to claim 10, wherein the prohibiting means generates an address separated by a certain distance before and after the address of the address control device for reading the image data into the storage device during encoding. When the preceding address exceeds the address for writing the image data to the storage device, the means for temporarily stopping the encoding process, and the slowing address exceeds the address of the address control device for writing the image data in the storage device. And a means for changing the encoding to a mode having a short encoding speed time such as an uncompressed mode code. 19. The first and second cyclic counters having a capacity equal to that of the storage device according to claim 10, wherein the first cyclic counter counts the number of image data written in the storage device at the time of encoding and the memory at the time of encoding. A second cyclic counter for counting the number of image data read from the device for encoding is provided, and a count value separated by a certain number before and after the count value of the image data written to the storage device is also output. When the count value to be advanced exceeds the count value of the number of image data read out for encoding, the encoding is temporarily stopped and it is prohibited to encode the area where the image data is not set. If the count value exceeds the count value of the number of read image data for encoding, change the encoding mode to a mode with a shorter encoding speed time, such as non-compressed mode code, and uncode. It is prohibited to write the image data again on the image data, or to output a count value separated by a certain number before and after the count value of the number of image data read from the storage device for encoding. If the preceding count value exceeds the count value of the number of written image data, the encoding is temporarily stopped to prohibit encoding to the area where image data is not set, and conversely the delayed count value. If the count value of the number of written image data is exceeded, change the coding mode to a mode with a short coding speed time such as non-compression mode code and write the image data again on top of the uncoded image data. An encoding / decoding device characterized by being forbidden. 20. The means for inhibiting according to claim 12, wherein at the time of decoding, an address which is delayed from an address value of an address control device for reading the decoded image data from the storage device to the output device is generated. And a means for temporarily stopping the decoding when the address for writing the decoded image data to the storage device circulates the delay address when the decoding is fast, and the decoded image data to the storage device. Means for generating an address preceding the address value of the address controller for writing, and suspending decoding when the address circulates and exceeds the address for reading the decoded image data from the storage device to the output device An encoding / decoding device comprising: 21. The means according to claim 12, wherein the prohibiting means generates an address before and after the address value of the address control device for reading the decoded image data from the storage device to the output device during decoding. , If the decoding is fast, the means for writing the decoded image data to the storage device goes past the slower address and the means for pausing when the address exceeds and the preceding address writes the decoded image data to the storage device. When the address is exceeded, it is a means to issue a wait command to the output device side to stop the output of undecoded data to the output device, or alternatively, to write the decoded image data to the storage device. The means for generating the address before and after, and the address that precedes the cycle if the decoding is fast, makes a cycle to read the decoded data to the output device. A means to temporarily stop the decoding when the address is exceeded, and a wait command is issued to the output device to output the undecoded data to the output device when the address for reading the decoded data to the output device exceeds the delayed address. An encoding / decoding device comprising means for stopping the output of. 22. The means for inhibiting according to claim 12, wherein the prohibition means is a first and second cyclic counter equal to the capacity of the storage device, and counts the number of decoded data written in the storage device at the time of decoding. A counter and a second cyclic counter for counting the number of decoded data read from the storage device to the output device at the time of decoding, a means for outputting a count value preceding the count value of the number of image data written in the storage device, and the decoding If the preceding count value circulates the count value of the data read to the output device and passes, the decoding is temporarily stopped, or the number of decoded data read from the storage device to the output device is counted. A means to output a count value that is slower than the count value and a count value that writes the decoded data to the storage device when the decoding is fast. An encoding / decoding device comprising: means for pausing the decoding when the base count value is circulated and overtaken. 23. The first and second cyclic counters according to claim 12, wherein the first and second cyclic counters have a capacity equal to that of the storage device, and count the number of decoded data written in the storage device at the time of decoding.
A cyclic counter and a second cyclic counter for counting the number of decoded data read from the storage device to the output device at the time of decoding are provided, and a count value separated by a certain number before and after the count value of the number of image data written in the storage device. If the preceding count value circulates and overtakes the count value of the data read to the output device when the decoding is fast, the decoding is paused and the decoded image data that has not been output to the output device is output. When the writing of the decoded data to the area is stopped again and the count value of the decoded data read to the output device exceeds the delay count delay, a wait command is issued to the output device to prohibit the output of undecoded data, or , A count value separated by a certain number is output before and after the count delay of the number of read image data from the storage device to the output device, and the decoding is performed. If the count value at which the decoded data is written to the storage device has passed the delay count value, the decoding is temporarily stopped and the writing of the decoded data to the output device to the output image device is prohibited. An encoding / decoding device characterized in that when the preceding count value exceeds the count value of the decoded data written to the storage device, a wait command is issued to the output device to prohibit the output of undecoded data. 24. The encoding / decoding device according to claim 10, a storage device connected to a bus for inputting an image signal, the storage device having a capacity of one document or less, and a command for reading a document. An original reading system comprising a start / stop command input means. 25. A facsimile apparatus comprising the document reading apparatus according to claim 24. 26. A filing system comprising the document reading device according to claim 24. 27. The encoding / decoding device according to claim 12, and a storage device connected to a bus for outputting decoded data, the storage device having a capacity of one document or less.
A coded data decoding system, characterized by comprising start / stop command input means for outputting decoded data. 28. A facsimile apparatus comprising the coded data decoding system according to claim 27. 29. A document image output device comprising the coded data decoding system according to claim 27. 30. An image processing apparatus comprising: the encoding device according to any one of claims 1 to 4; and the decoding device according to any one of claims 5 to 8. ..