KR940002976B1 - Picture data changing device for fax system - Google Patents

Abstract

The converter comprises an interface for generating address and clock control signal according to the resolution conversion data, a buffer for providing enable signal when data is present in the internal storage, a line memory for storing 1 line picture data out of the buffer, an address generator for loading address onto the memory according to the conversion starting signal from the interface and a clock controller providing clock to the latch according to the resolution conversion signal.

Description

The resolution and linear density converter of the image data of the facsimile system

1 is a block diagram of a conventional facsimile system.

2 is a block diagram of a facsimile system according to the present invention.

3 is a circuit diagram of a resolution converter according to the present invention.

The present invention relates to a resolution converting apparatus in a facsimile system for transmitting and receiving image data, and more particularly, to a converting apparatus for reducing / enlarging image data of a facsimile system at a desired ratio.

In current digital networks, it is recommended to enable data exchange with the G3 and G4 facsimiles recommended in the CCITT Recommendations. In the G3 facsimile system, the resolution of the scanner and printing is 200x100 DPI (Dot Per Inch) (scanning direction x subscanning resolution) or 200x200 DPI. In addition, the resolution of the high-resolution high end system scanner and printer, which is the G4, is 400 × 400 DPI, or the resolution of the printer is higher than that of the scanner.

Therefore, when the image data scanned and transmitted from the G3 facsimile is received by the G4 facsimile system, 200 × 200 DPI or 200 × 100 DPI low resolution data is converted into 400 × 400 DPI high resolution printing data.

In addition, even when copying from a high-end system designed for a scanner whose resolution is lower than that of the printer, a resolution conversion technology that matches the resolution of the scanned data at the resolution of the printer is required.

1 is a block diagram of a general facsimile system, and performs system control according to an OPE (Operating Pannel) 12 generated by pressing a key of an operation mode or the like and a control command of the OPE 12. A microprocessor (MPU) 14, a scanner 16 for scanning the main and sub-scanning of a document set under the control of the MPU 14 at a predetermined resolution, and outputting data, and under the control of the MPU 14; A scanner interface (hereinafter referred to as " SIF ") 18 for driving the scanner 16 and interfacing the output data of the scanner 16 with the system, and scanning under the control of the MPU 14; A memory 24 for accessing the generated image data, a codec 20 for encoding and decoding input image data and outputting the same, and under the control of the MPU 14, Transfer the stored data of the memory 24 to the codec 20. Direct memory access controller (DMAC) 22, a printer 26 for printing input image data, and data output from the memory 24 under the control of the DMAC 22 to interface with the printer 28. A printer interface (hereinafter referred to as " PIF ") 26, a modem for modulating and transmitting the coded data coded by the codec 20 to the telephone line 32 and demodulating the modulated received signal; It consists of a LIU (Line Interface) 30.

15 in the configuration of FIG. 1 transfers an address, data, control signals, etc. as a system bus.

First, the conventional operation will be described with reference to FIG.

When the original is inserted into the facsimile system as shown in FIG. 1, the MPU 14 detects the size of the inserted original by the original size detection sensor in the SIF 18. At this time, the scan resolution of the original to be scanned is set to the system's initial resolution value unless otherwise specified.

If the user inputs the subscriber number of the other station through the OPE 12 and presses the start key, a corresponding command is generated from the MPU 14 and the SIF 18 is executed. Is passed on. The SIF 18 which inputs a command from the MPU 14 generates a general signal or the like for driving the scanner 16 at a predetermined resolution and linear density to drive the scanner 16. The image data read out from the scanner 16 is stored in the memory 24 by the DMA 22. The image data stored in the memory 24 is moved to the codec 20 by the DMA 22 and encoded in a desired encoding form. Encoded image data is transmitted to the modem unit in the internal buffer by the DMAC function in the codec 20. The modem and the modem unit in the LIU 30 are modulated by the modem unit and then transmitted to the telephone line passage through the LIU (Line Interface Unit) at a transmission rate that matches the line status.

On the contrary, in the case of reception, the data is processed in the reverse operation of the transmission, and the image data decoded by the codec 20 is transmitted from the memory 24 to the PIF 26 by the DMAC 22, and the printer 28 It is printed to obtain the original original image output.

If the resolution and line density of the other station and itself, i.e., the transmitting station, are different, the resolution and line density should be converted at either of the transceiver stations. When the transmitting station converts the resolution and the linear density, after converting the image data stored in the memory 24 through the SIF 18 by the software of the MPU 14 that knows the desired conversion ratio by the protocol communication with the other station, it is again converted. Stored in memory 24. The stored data of the memory 24 having completed the resolution conversion is accessed by the DMAC 22 and input to the codec 20. As described above, the data input to the codec 20 is transmitted to the modem and the LIU 30, modulated, and then transmitted to the opposite station through the telephone line 32.

However, the facsimile system as shown in FIG. 1 causes the burden of the program of the MPU 14 by processing the resolution conversion by the software in the MPU 14, and has a problem that the processing time is very late.

Accordingly, an object of the present invention is to provide an apparatus for converting image data having a predetermined resolution and linear density by hardware in a system for transmitting and receiving image data.

Another object of the present invention is to provide an apparatus for converting image data having a predetermined resolution and linear density into image data having a desired resolution and linear density, and recording the result into a memory.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

2 is a hardware block diagram of a facsimile system according to the present invention, wherein the SIF 18 is controlled by the MPU 14 between the memory 24 and the system bus 15 that access image data by a predetermined control. A converter 32 for converting the resolution and the linear density of the image data outputted from) is connected. Other configurations and reference numerals are the same as those in FIG.

3 is a circuit diagram of the resolution converting apparatus according to the present invention, which is a detailed view of the converter 32 shown in FIG.

The MPU interface unit (hereinafter referred to as MPU I) for inputting resolution conversion information and conversion start signal (converter on / off signal) from the MPU 14 and outputting an address generation control signal and a clock control signal according to the resolution conversion 34) and a buffer 36 for buffering the scanned image data output from the SIF 18, and outputting an enable signal when there is data in the internal storage area, and the buffer 36 A line memory 38 for storing and outputting one line of image data outputted from 36, a clock generator 40 for generating a clock of a predetermined period, and the MPU I / F unit 34 An image outputted at a predetermined cycle from the line generator 38 and the address generator 42 for generating an address of the memory according to the resolution conversion information and inputting the memory address according to the resolution conversion information. Data conversion clock The clock generator may be operated according to a latch 44 outputting a latch according to a speed and an enable signal output from the buffer 36 and according to resolution conversion information output from the MPU I / F unit 34. A clock control unit 46 which varies the clock of 40 and provides the clock of the latch 44; and a line of image data whose resolution and linear density are converted by counting a resolution conversion clock outputted from the clock control unit 46; And a line detection counter 48 for inputting the number to the MPU I / F section 34.

Hereinafter, a resolution conversion embodiment according to the present invention will be described in detail.

Now, when the user inputs the information necessary to read the communication and the original, such as the subscriber number of the other station and the scanning resolution of the scanner 16, through the OPE 12, the MPU 14 presses the scanning start key. After recognizing the key signal, the SIF 18 sends information about the scan command and the resolution. The SIF 18, which receives the scan command and the resolution information from the MPU 14, drives the scanner 16 according to the resolution and the linear density to read the data and reads the data through the bus 15 and 15a. Save it to 24).

When the data for one page is processed by processing the image data for one line of the original set by the control of the scanning as described above, the MPU 14 uses the modem and the LIU 30 to communicate with the other station and the possibility of communication. Performs low-speed protocol exchange on possible resolutions, and communicates resolution, line density conversion, coding scheme, line status, etc. with the other station.

When resolution conversion is required by the protocol communication as described above, for example, if the resolution of the own scan data is G3 and the counterpart is G4, the MPU 14 sends the converter 32 via the system bus 15 to the converter 32. The corresponding degree conversion information and a start signal (converter on / off) signal are output.

The resolution conversion information is the conversion ratio information of the main scan and the sub scan of the image data. The resolution conversion information and the start signal output from the MPU 14 are input to the MPU I / F unit 34 in FIG. The MPU I / F unit 34 which inputs the resolution conversion information and the operation start control information for the main scan and the sub-scan conversion from the MPU 14, controls the address generation for storing the converted data in the memory 24. The reference clock is controlled by supplying information on conversion through the signal and the terminals P1 and P2 to the address generator 42 and the clock controller 46.

The address generation unit 42 for inputting the address generation control signal output from the MPU I / F unit 34 to the terminal P9 is operated by the control signal, and the resolution conversion information input to the terminal P10. Generates an address with a period according to The address signal output from the address generator 42 is input as an address signal of the memory 24 that accesses image data.

On the other hand, the buffer 36 receives the image data from the SIF 18 of FIG. 2 and outputs the image data to the line memory 38. The buffer 36 transmits an enable signal through the terminal P3. ).

The line memory 38 connected to the output terminal of the buffer 36 stores the image data output from the buffer 36 line by line and outputs the line data to the latch 44.

At this time, the clock control unit 46 which inputs the enable signal output from the buffer 36 and the resolution conversion information output from the MPU I / F unit 34 to the terminals P5 and P6 is a reference clock generator ( The reference clock output from 40 is changed to a changed resolution clock and provided as a clock of the latch 44. That is, the clock control unit 46 converts and outputs the reference clock which is operated by the input signal of the terminal P5 to the resolution clock corresponding to the resolution conversion control signal of the terminal P6.

For example, if twice the high resolution conversion information is inputted when the clock of the image data output from the scanner is CLK, the clock controller 46 doubles the clock CLK generated from the reference clock generator 40. It is variable by the conversion clock 2CLK and output to the latch 44 and the line detection counter 48.

At this time, the latch 44 latches the image data of one line output from the line memory 38 into a clock supplied from the clock controller 46 and inputs the data data to the data terminal of the memory 24. Accordingly, it can be seen that the data output from the line memory 38 is output from the latch 44 at twice the transmission speed by the resolution conversion clock, thereby increasing the resolution.

On the other hand, the MPU is counted by counting the number of data lines of the converted data (line detect counter) 48 to which the clock supplied to the terminal P4 of the latch 44 is input. When 14 stops the operation of the converter 32, it is used to inform the MPU 14 via the terminals P7 and P8 of the MPU I / F section 34. That is, the number of controlled clocks supplied to the clock terminal P4 of the latch 44 part is counted so that the MPU 14 that detects the number of lines and outputs them to the MPU I / F part 34 is recognized.

Accordingly, the MPU 14 can access the signal through the terminal P8 of the I / F unit 34 so as to know whether the current and the line have been converted.

As described above, the present invention converts the resolution of image data as a hardware operation, thereby making it possible to perform transmission / reception at the time of resolution conversion at high speed and reduce the program burden on the system controller.

Claims (2)

A system control unit for analyzing an input signal and controlling a resolution conversion operation; scanning means for converting an image of an original into an electrical signal and outputting scan data under the control of the system control unit; and scanning under control of the system control unit A resolution and linear density conversion apparatus for image data of a facsimile system having a memory for accessing data, comprising: inputting resolution conversion information and a conversion start signal from the system control unit to generate an address generation control signal and a clock control signal according to the resolution conversion; And a buffer 36 for inputting and buffering the scanned image data output from the SIF 18, and outputting an enable signal when there is data in the internal storage area, and the buffer 36. A line memory 38 for storing and outputting one line of image data to be output from An address generator 52 which is operated by a conversion start signal output from the interface unit 34 and generates an address of the memory according to the resolution conversion information and inputs it into the memory 24; and the line memory 38; A latch 44 for latching and outputting image data output at predetermined intervals from the buffer according to the resolution conversion clock speed, and an enable signal output from the buffer 36, and output from the interface unit 34. And a clock control unit (46) for varying a clock of a predetermined period according to the resolution conversion information to be provided as a clock of the latch (44). The line detection counter 48 according to claim 1, further comprising: a line detection counter 48 for counting a resolution conversion clock output from the clock control section 46 and inputting the number of lines of image data whose resolution and line density are converted to the interface section 34; And a resolution and line density conversion device for image data of a facsimile system.