JP3308995B2 - Image receiving device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image receiving apparatus in a communication terminal such as a facsimile.

[0002]

2. Description of the Related Art FIG. 10 shows a schematic configuration of a conventional facsimile apparatus. A scanner 102 and a printer 103 are connected to a reading / recording control unit 101. At the time of transmission, the original read by the scanner 102 is converted into an image signal, encoded by the encoding / decoding circuit 105 of the main control / communication control unit 104, and transmitted to the line. At the time of reception, the encoded data sent from the line is decoded by the encoding / decoding circuit 104 and sent to the reading / recording control unit 101, where recording is performed by controlling the printer 103. Therefore, exchange of image data between the reading / recording control unit 101 and the main control / communication control unit 104 is performed using raw data before encoding or after decoding.

FIG. 11 shows a schematic configuration of another conventional facsimile apparatus, and includes communication control units 11a, 111b, 1
11c is assigned to each line, and each has an encoding / decoding circuit 112a, 112b, 112c. The reading / recording control unit 113 includes an encoding / decoding circuit 114, a scanner 115, and a printer 116.
Is connected. Each encoding / decoding circuit 112a-1
Reference numerals 12c and 114 are connected to an encoding / decoding circuit 118 of the main control unit 117 via an encoded data bus 119. That is, exchange of image data in each unit is performed by encoded data via the encoded data bus 119. For example, the encoded data sent from the G4 line is sent to the encoded data bus 119 as it is, and the encoding / decoding circuit 11 of the reading / recording control unit 113 is used.
4 and output by the printer 116.

By the way, in a facsimile apparatus capable of supporting the G4 class, the recording density is higher than that of the G3 class compatible machine in order to enable more precise recording. Therefore, for example, the received data transmitted at 200 dpi is 4
It is necessary to convert the data to 00 dpi and record it. When such pixel density conversion is performed, pixels are enlarged by pixel interpolation so that images of the same size can be recorded before and after conversion. The pixel interpolation includes an interpolation method (hereinafter, referred to as smoothing) suitable for character image data that makes the step-like jaggedness inconspicuous by referring to the peripheral pixels of the print pixel, and an image signal according to the pixel enlargement magnification. And an interpolation method suitable for photographic image data to be interpolated with the same signal. This depends on the fact that the character image data is a binary signal of white and black, and the photographic image data is a binary signal whose area is modulated in order to reproduce halftones.

FIG. 12 shows a schematic configuration of a conventional image receiving apparatus for performing such pixel interpolation. In FIG. 12, reference numeral 121 denotes a decoding circuit for decoding received encoded data, 122 denotes a storage circuit for temporarily storing decoded image data, and 123 denotes a smoothing process for a necessary portion of the decoded data. A smoothing processing circuit 124 performs a recording unit for recording the smoothed image data on paper, and a control unit 125 controls these units. The control unit 125 sends a clear signal CLR to each circuit prior to reception and, when performing smoothing of received data, sends a select signal SELC to the smoothing processing circuit 123 in advance according to a user's instruction. When a request signal REQ for encoded data is transmitted to the partner device through the decoding circuit 121, the encoded data DATA is transmitted from the partner device in synchronization with the clock DCLK. When the data transfer for one page is completed, the control unit 12
5 sends a decoding start signal DSTR to the decoding circuit 121, and the decoding circuit 12 starts decoding the coded data DATA, and outputs the decoded image signal PPIX to the clock PC.
It is sent to the storage circuit 122 together with the LK. When the decoding of one page is completed, the decoding circuit 121 outputs a decoding end signal DEND to the control unit 125, and the control unit 125 sends a read start signal RSTR to the storage circuit 122, and stores the stored image signal MPIX. To the smoothing processing circuit 123 together with the clock MCLK. The smoothing processing circuit 123 performs smoothing on a required portion of the image signal MPIX, and outputs the processed image signal SPIX to the clock SCLK.
Is sent to the recording unit 124. When reading of one page is completed, the storage circuit 122 sends a read end signal REND to the control unit 125, and the control unit 125
4 is sent a recording start signal PSTR. The recording unit 124 stores the sent image signal SPIX, and starts recording in response to a recording start signal. When the recording of one page is completed, the recording unit 124 transmits a recording end signal PE to the control unit 125.
Send ND.

[0006]

As described above, in the above-described conventional image receiving apparatus, when the pixel is enlarged, the user is not required to perform the interpolation, although there is an interpolation method suitable for each of the character image data and the photographic image data. in advance either way to select one has been taken. For this reason, when character image data and photo image data are mixed in one page, if an interpolation method suitable for the character image data is used, the area ratio between white and black of the photo image data changes, so When the interpolation method suitable for the photographic image data is used, the stepped jaggedness of the character image data is recorded as it is, so that there is a problem that the printed character becomes unsightly.

The present invention solves such a conventional problem, and provides an image receiving apparatus capable of performing pixel enlargement by an interpolation method suitable for each of character image data and photographic image data. Aim.

[0008]

In order to achieve the above object, the present invention provides a means for measuring a total time required for decoding received data, and a method for measuring the obtained total decoding time by the number of lines or the number of lines. Means for calculating the average decoding time by averaging with the number of bits, and comparing the average decoding time with a preset reference value. If the average decoding time is shorter than the reference value, the received data is determined to be character image data. If it is long, it is determined that the image data is photographic image data.
Performs smoothing processing for character images and converts them to photographic image data.
Smoothine that performs smoothing processing for photographic images
And processing means .

The present invention also provides a means for measuring the time required for decoding received data for each line or for every N bits, and for comparing the obtained unit decoding time with a preset reference value. means for counting the number of times when the unit decoding time is long relative to, is less than another reference value that this number is set in advance, it is determined that the character image data, if large means for determining an image data To character image data
For text image smoothing processing,
Performs photographic image smoothing on data.
And a smoothing processing means .

[0010] The present invention also includes means for measuring the time required for decryption of the received data for each line unit or N bits is compared with a reference value unit previously sets the decoding time obtained, line unit hand determined or if the unit decoding time is shorter, it is determined the received data and character image data with respect to a reference value for each N bits is longer than the photographic image data
Columns and text image smoothin for character image data
Processing, and the photographic image data
And a smoothing means for performing a smoothing process .

[0011] The present invention also relates to a method of receiving encoded data.
Means for measuring the amount of received data per in or N bits, and comparing the obtained received data amount with a preset reference value, and when the received data amount is smaller than the reference value, determining that the received data amount is character image data; If there are many photos and image data
Means for determining and for character image data
Performs smoothing processing, and applies
Smoothing processing means for performing smoothing processing for true images
It is provided with.

[0012]

[0013]

According to the present invention, the time required for decoding the received coded data or the amount of received data or the communication time differs between the character image data and the photographic image data. By comparing with a preset reference value, it is possible to determine whether the received data is character image data or photographic image data. Therefore, the reference value is determined in units of one document, one page, one line, or N bits, so that the character image data can be determined for each document, one page, one line, or N bits. Can be determined, pixel interpolation can be performed by a method suitable for each image data, and a clear and good-looking recorded image can be obtained.

[0014]

(Embodiment 1) FIG. 1 shows the structure of a first embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a decoding circuit, which decodes encoded data transferred from an external circuit (not shown) and converts the encoded data into monochrome print data. Reference numeral 2 denotes a timer for measuring a total decoding time required for decoding the encoded data and converting the encoded data into print data. A line counter 3 counts the total number of print data lines. Reference numeral 4 denotes an average value calculation circuit, which divides the measurement value of the timer 2 by the number of lines of the line counter 3 to calculate an average decoding time per line. 5 is a memory circuit,
Print data is temporarily stored. Reference numeral 6 denotes a comparator which compares a preset reference value A with an average decoding time c output from the average value calculation circuit 4, and outputs "0" when the reference value A> the average decoding time c. Is set, and when the reference value A ≦ the average decoding time c, “1” is set to the output d. 7
Is a latch circuit for latching the output d of the comparator 6.
Reference numeral 8 denotes a smoothing processing circuit which performs smoothing for a character image when the output e of the latch circuit 7 is "0", and performs smoothing for a photographic image when the output e is "1". A recording unit 9 has a built-in storage circuit for storing one page of recording data, and records data according to the recording data. Reference numeral 10 denotes a control unit that controls the above units.

FIG. 2 shows a ROM table 11 for generating a reference value A. Three elements, ie, an x value representing an encoding system, a y value representing a format size, and a z value representing a line density are inputted. Thus, the reference value A is determined.

The smoothing processing circuit 8 has a ROM 12 as shown in FIG.
LK and the image signals MPIX0 to MPIX8 and the latch output e from the latch circuit 7 are input, and the clock SCLK and the image signals SPIX0 to SPIX3 are output. Input image signal MPIX0
8 are the target pixels MPI at the time of printing as shown in FIG.
X4 and its surrounding eight pixels.
X4 is doubled in each of the following embodiments in the main scanning direction and the sub-scanning direction. Also, the ROM 12
As shown in FIG. 5, each of the input pixels MP has a smoothing area for a document image and a smoothing area for a photographic image.
The most suitable smoothing is performed in accordance with the black and white information of the IX.

Next, the operation of the above embodiment will be described.
Prior to printing, the control unit 10 first outputs a clear signal CLR to clear each circuit of each unit, and then outputs a request signal REQ of encoded data to an external circuit (not shown). When the external circuit receives the request signal REQ,
The valid section signal DENB is made valid, the encoded data DATA is transferred to the decoding circuit 1 in synchronization with the clock DCLK, and when the transfer of one page of data is completed, the valid section signal DENB is made invalid. When the valid section signal DENB becomes invalid, the control section 10 outputs a decoding start signal DSTR to the decoding circuit 1. When the decoding start signal DSTR is input, the decoding circuit 1 starts decoding, and stores the valid section signal LENB and the clock PC in the storage circuit 5 line by line.
LK and the image signal PPIX are output, and the storage circuit 5 sequentially stores the transferred image signal PPIX. Control unit 1
0 outputs a start signal TSTR to the timer 2 at the same time as outputting the decoding start signal DSTR, and the timer 2 starts measuring time in response to the start signal TSTR. The line counter 3 sequentially counts the number of valid section signals LENB. When the decoding circuit 1 detects the end of the received data from the transferred encoded data, the decoding circuit 1
To output a decoding end signal DEND. The control unit 10
The stop signal TSTP is output to the timer 2 and the timer 2
Stops the time measurement in response to the stop signal TSTP. The average value calculation circuit 4 divides the measured value b of the timer 2 by the number of lines a of the line counter 3 to calculate an average decoding time per line. The comparator 6 compares the preset reference value A with the average decoding time value c output from the average value calculation circuit 4, and outputs “0” when the reference value A> the average decoding time value c. Is set, and when the reference value A ≦ the average decoding time c, “1” is set to the output d. Control unit 1
0 outputs the latch signal LATH to the latch circuit 7 to latch the output signal d of the comparator 6, and outputs the read start signal RSTR to the storage circuit 5. Storage circuit 5
Receives the read start signal RSTR, sequentially transfers the stored image signals MPIX0 to MPIX8. At this time, the peripheral image signal is also transferred together with the image signal to be transferred. The smoothing circuit 8 outputs the transferred image signal M
As shown in FIG. 4, the pixels are enlarged by a factor of two in the main scanning and the sub-scanning from PIX0 to PIX8. When the signal e is "0", as shown in FIG.
Is smoothed for the image signal from image data to 1FFH, and when the signal e is "1", the address 20
The image signal from 0H to 3FFH is subjected to photographic image smoothing, and the processed image signals SPIX0 to SPIX3 are sequentially transferred to the recording unit 9. The recording unit 9 sequentially stores the image signals SPIX0 to SPIX3 in a storage circuit capable of storing image signals for one page. On the other hand, when all the stored data has been transferred, the storage circuit 5 outputs an end signal REND to the control unit 10. When receiving the end signal REND, the control unit 10 outputs a recording start signal PSTR to the recording unit 9, and the recording unit 9 records the stored image signal. The recording end signal PEND is output. When the recording end signal PEND is input, the control unit 10 knows that the recording has ended, and ends a series of operations.

As described above, according to the first embodiment,
The total time required to decode the received encoded data was measured, the obtained total decoding time was averaged by the total number of lines to obtain an average decoding time, and the average decoding time was set in advance. Compared with the reference value A, if the average decoding time is shorter than the reference value A, it is determined that the received data has a large amount of character image data. It is possible to determine whether there is a large amount of image data or a large amount of photographic image data, and even if character image data and photographic image data are mixed, 1
Pixel enlargement can be performed for each document by an interpolation method suitable for each image data.

In the first embodiment, the character image or the photographic image is determined based on the average decoding time per line in one document. However, the average decoding per N bits, not per line. You may make it determine both from time. Alternatively, both may be determined from the average decoding time of the entire page instead of the entire document.

(Embodiment 2) FIG. 6 shows the configuration of a second embodiment of the present invention. In FIG. 6, a decoding circuit 21 decodes encoded data transferred from an external circuit (not shown) and converts the encoded data into print data. 22
Is a timer for measuring a decoding time for each line required to decode the encoded data. Reference numeral 23 denotes a comparator which compares a preset reference value B with a decoding time a measured by the timer 22, and sets "0" to an output b when the reference value B> the decoding time a. If the value B ≦ the decoding time a, “1” is set to the output b. Numeral 24 denotes a counter, and when the output b of the comparator 23 is "1", the control unit 3
When a clock signal is input from 0, the count value is incremented. A storage circuit 25 temporarily stores print data. Reference numeral 26 denotes a comparator, which compares another preset reference value C with the output value c of the counter 24, and sets “0” to the output d when the reference value C> the output value c. If ≤output value c, set "1" to output d. A latch circuit 27 latches the output d of the comparator 26. Reference numeral 28 denotes a smoothing processing circuit which performs character image smoothing when the output e of the latch circuit 27 is "0".
When it is "1", smoothing for a photographic image is performed.
A recording unit 29 has a built-in storage circuit for storing one page of recording data, and records according to the recording data. Reference numeral 30 denotes a control unit, which controls the above units.

The reference value B or C is generated by a ROM table similar to that of the first embodiment. An x value indicating an encoding method, a y value indicating a format size, and a z value indicating a line density are used. The three elements of the value are input to determine reference values B and C.

Next, the operation of the second embodiment will be described. First, the control unit 30 outputs a clear signal CLR to clear each circuit of each unit, and then outputs a request signal REQ of encoded data to an external circuit (not shown). When this request signal REQ is input, the external circuit makes the valid section signal DENB valid, transfers the encoded data DATA to the decoding circuit 21 in synchronization with the clock DCLK, and completes the transfer of one page of data. Then, the valid section signal DE
Disable NB. The control unit 30 controls the valid section signal DEN
When B becomes invalid, the decoding circuit 21 outputs a decoding start signal D
STR, and outputs a clear signal TCLR to the timer 22. The decoding circuit 21 starts decoding when the decoding start signal DSTR is input, and the storage circuit 25 for one line
To output the valid section signal LENB, the clock PCLK and the image signal PPIX. The storage circuit 25 sequentially stores the transferred image signals PPIX. The control unit 30 outputs the decoding start signal DSTR to the decoding circuit 21 and simultaneously outputs the start signal TSTR to the timer 22, and the timer 22 starts measuring the time when receiving the start signal TSTR. When the decoding of one line is completed, the decoding circuit 21 sends a one-line decoding end signal D to the control unit 30.
END is output. When the one-line decoding end signal DEND is input, the control unit 30 outputs a stop signal TSTP to the timer 22, and the timer 22 stops measuring time when receiving the stop signal TSTP. Comparator 23
Compares the preset reference value B with the decoding time value a measured by the timer 22, sets “0” to the output b when the reference value B> the decoding time value a, and sets the reference value B ≦ In the case of the decoding time value a, "1" is set to the output b. The control unit 30
The clock signal CCLK is output to the counter 24, and the counter 24 increments the count value when the clock signal CCLK is input while the output b of the comparator 23 is "1". Next, the control unit 30 outputs the decoding start signal DSTR to the decoding circuit 21 and outputs the clear signal TCLR to the timer 22. When detecting the end of the data from the transmitted encoded data, the decoding circuit 21
0, the decoding end signal DFIN is output, and the control unit 30
The above operation is repeated until the decoding end signal DFIN is input.

The comparator 26 compares the preset reference value C with the output value c of the counter 24, and sets “0” to the output d when the reference value C> the output value c. In the case of the output value c, "1" is set to the output d. The control unit 30
When the decoding end signal DFIN is input, the latch circuit 2
7, a latch signal LATH is output to latch the output signal d of the comparator 26, and a read start signal RSTR is output to the storage circuit 25. Upon receiving the read start signal RSTR, the storage circuit 25 stores the stored image signal M
PIX0 to PIX8 are sequentially transferred. At this time, the peripheral image signal is also transferred together with the image signal to be transferred. The smoothing processing circuit 28 receives the transferred image signal MPI
From X0 to X8, 2 for each of main scanning and sub-scanning
The pixel is enlarged twice. In this case, when the signal e is “0”, smoothing for the character image is performed, and the signal e becomes “1”.
In the case of, the photographic image smoothing is performed and the processed image signals SPIX0 to SPIX3 are sequentially transferred to the recording unit 29. The recording unit 29 sequentially stores the image signals SPIX0 to SPIX3 in a storage circuit capable of storing image signals for one page. On the other hand, when all the stored data has been transferred, the storage circuit 25 outputs a read end signal REND to the control unit 30. When the control unit 30 receives the read end signal REND,
A recording start signal PSTR is output to the recording unit 29, and the recording unit 2
9 records the stored image signal, and outputs a recording end signal PEND to the control unit 30 when the recording is completed. When the recording end signal PEND is input, the control unit 30 knows the end of the recording and ends a series of operations.

As described above, according to the second embodiment,
The decoding time is measured for each line unit required to decode the received encoded data, and the obtained decoding time is compared with a preset reference value B. The number of lines in the long case is counted, and the number is compared with a preset reference value C for each page. If the number is small relative to the reference value C, the received data is determined to be character image data. Since it is determined to be photographic image data, 1
It is possible to determine whether there is a lot of character image data or a lot of photographic image data for each page, and it is possible to enlarge pixels by an interpolation method suitable for each image data for each page.

In the second embodiment, the character image and the photographic image are determined for each page based on the number of lines in which the decoding time of one line exceeds the reference value B. Alternatively, the determination may be made from the number of times for each N bits exceeding the reference value of the decoding time. Alternatively, the determination may be made based on the number of times in one document, not in each page.

Embodiment 3 Next, a third embodiment of the present invention will be described with reference to FIG. In FIG. 7, a decoding circuit 31 decodes encoded data transferred from an external circuit (not shown) and converts the encoded data into monochrome print data. A timer 32 measures a decoding time for each line required to decode the encoded data. 3
Reference numeral 3 denotes a comparator, which has a preset reference value D and a timer 32.
Is compared with the decoding time value a measured in the above step. When the reference value D> the decoding time value a, the output b is set to “0”. When the reference value D ≦ the decoding time value a, the output b is set. Set “1”. A storage circuit 34 temporarily stores the print data and the output value b of the comparator 33. Reference numeral 35 denotes a smoothing processing circuit which performs smoothing for a character image when the output c of the storage circuit 34 is "0", and performs smoothing for a photographic image when the output c is "1". A recording unit 36 has a built-in storage circuit for storing one page of recording data, and records according to the recording data. Reference numeral 37 denotes a control unit which controls the above-described units.

The generation of the reference value D is based on the first
Is a ROM table similar to that of the first embodiment, and three elements of an x value indicating an encoding method, a y value indicating a format size, and a z value indicating a linear density are input, and a reference value A is determined.

Next, the operation of the third embodiment will be described. First, the control unit 37 outputs a clear signal CLR to clear each circuit of each unit, and then outputs a request signal REQ of encoded data to an external circuit (not shown). When this request signal REQ is input, the external circuit makes the valid section signal DENB valid, transfers the encoded data DATA to the decoding circuit 31 in synchronization with the clock DCLK, and completes the transfer of one page of data. Then, the valid section signal DE
Disable NB. The control unit 37 outputs the valid section signal DEN
When B becomes invalid, a decoding start signal D
STR, and outputs a clear signal TCLR to the timer 32. The decoding circuit 31 starts decoding when the decoding start signal DSTR is input, and the storage circuit 34 for one line
To output the valid section signal LENB, the clock PCLK and the image signal PPIX. The storage circuit 34 sequentially stores the transferred image signals PPIX. The control unit 37 outputs the start signal TSTR to the timer 32 at the same time as outputting the decoding start signal DSTR, and the timer 32 starts measuring time in response to the start signal TSTR. When the decoding of one line is completed, the decoding circuit 31 outputs a one-line decoding end signal DEND to the control unit 37.
When the one-line decoding end signal DEND is input, the control unit 37 outputs a stop signal TSTP to the timer 32, and the timer 32 stops measuring time in response to the stop signal TSTP. The comparator 33 compares the preset reference value D with the decoding time value a measured by the timer 32, and sets “0” to the output b when the reference value D> the decoding time value a. If the value D ≦ the decoding time value a, “1” is set to the output b. The control unit 37 outputs the latch signal LATH to the storage circuit 34, and the storage circuit 34 stores the output signal b of the comparator 33 in correspondence with the currently processed data of one line. Next, the control unit 37 outputs the decoding start signal DSTR to the decoding circuit 31 and outputs the clear signal TCLR to the timer 32.
Upon detecting the end of the data from the transmitted encoded data, the decoding circuit 31 sends a decoding end signal D to the control unit 37.
FIN, and the control unit 37 outputs the decoding end signal D
The above operation is repeated until FIN is input.

When the decoding end signal DFIN is input, the control section 37 stores the read start signal RST in the storage circuit 34.
R, and the storage circuit 34 outputs the read start signal RST
The image signals MPIX0 to MPIX8 are sequentially transferred with the signal b corresponding to the image signal received and stored as the signal c. At this time, the peripheral image signal is also transferred together with the image signal to be transferred. The smoothing processing circuit 35 enlarges the pixels twice in each of the main scanning and the sub-scanning from the transferred image signals MPIX0 to MPIX for each line. At this time, when the signal c is "0", smoothing for a character image is performed, and when the signal c is "1", smoothing for a photographic image is performed, and the processed image signals SPIX0 to SPIX3 are sequentially stored in the recording unit 36. Forward. The recording unit 36 sequentially stores the image signals SPIX0 to SPIX3 in a storage circuit capable of storing image signals for one page. On the other hand, when all of the stored data has been transferred, the storage circuit 34 sends an end signal REND to the control unit 37.
Is output. When receiving the end signal REND, the control unit 37 outputs a recording start signal PSTR to the recording unit 36,
The recording unit 36 records the stored image signal, and outputs a recording end signal PEND when the recording is completed. When the recording end signal PEND is input, the control unit 37 knows the end of the recording, and ends a series of operations.

As described above, according to the third embodiment,
The decoding time required to decode the received coded data is measured for each line, and the obtained decoding time is compared with a preset reference value D. If it is shorter, the received data is determined to be character image data,
If the image data is long, it is determined that the image data is photographic image data. Therefore, it is possible to determine whether there is a large amount of character image data or a large amount of photographic image data for each line. Pixel enlargement can be performed.

In the third embodiment, the character image and the photographic image are discriminated based on whether the decoding time of one line exceeds the reference value D. However, the decoding is not limited to one line but every N bits. Alternatively, the determination may be made from the activation time.

Embodiment 4 Next, a fourth embodiment of the present invention will be described with reference to FIG. In FIG. 8, reference numeral 41 denotes a decoding circuit, which decodes encoded data transferred from an external circuit (not shown) and converts it into print data. A data amount detection circuit 42 counts the transfer clock DCLK of the encoded data and detects the data amount. A line counter 43 counts the number of print data lines. An average value calculation circuit 44 divides the measurement value of the data amount detection circuit 42 by the number of lines of the line counter 43 to calculate an average encoded data amount per line. A storage circuit 45 temporarily stores the print data. Reference numeral 46 denotes a comparator, which is a reference value E set in advance and an average coded data amount value c output from the average value calculation circuit 44.
When the reference value E> the average encoded data amount value c, the output d is set to “0”. When the reference value E ≦ the average encoded data amount value c, the output d is set to “1”. set. A latch circuit 47 latches the output d of the comparator 46. 48 is a smoothing processing circuit which performs smoothing for a character image when the output e of the latch circuit 47 is "0";
When it is "1", smoothing for a photographic image is performed.
A recording unit 49 has a built-in storage circuit for storing one page of recording data, and records according to the recording data. Reference numeral 50 denotes a control unit, which controls the above units.

The ROM table for generating the reference value E is
This is the same as the first embodiment described above. The x value indicating the encoding method, the y value indicating the format size, and the z value indicating the linear density are used.
A reference value E is determined from the three elements of the value.

Next, the operation of the fourth embodiment will be described. First, the control unit 50 outputs a clear signal CLR to clear each circuit of each unit, and subsequently outputs a request signal REQ of encoded data to an external circuit (not shown). When this request signal REQ is input, the external circuit enables the valid section signal DENB, transfers the encoded data DATA to the encoding circuit 41 in synchronization with the clock DCLK, and completes the transfer of one page of data. Then, the valid section signal DEN
Invalidate B. During this time, the data amount detection circuit 42 counts the transfer clock DCLK of the encoded data. When the valid section signal DENB becomes invalid, the control unit 50 outputs a decoding start signal DSTR to the decoding circuit 41. When the decoding start signal DSTR is input, the decoding circuit 41 starts decoding the encoded data, and outputs a valid section signal LENB, a clock PCLK, and an image signal PPIX to the storage circuit 45 in line units. The storage circuit 45 sequentially stores the transferred image signals PPIX. Control unit 50
Outputs the decoding start signal DSTR, the line counter 43 sequentially counts the number of valid section signals LENB, and the decoding circuit 41 detects the end of the data from the transferred encoded data, The decoding end signal DE is set to 50.
ND is output. The average value calculation circuit 44 calculates the measured value b of the data amount detection circuit 42 by the line number a of the line counter 43.
To calculate the average encoded data amount per line. The comparator 46 compares the preset reference value E with the average encoded data amount value c output from the average value calculation circuit 44, and outputs the output d when the reference value E> the average encoded data amount value c. “0” is set, and “1” is set to the output d when the reference value E ≦ the average encoded data amount value c. The control unit 50
The latch circuit 47 outputs the latch signal LATH to latch the output signal d of the comparator 46, and
5, the read start signal RSTR is output. Storage circuit 4
5 receives the read start signal RSTR and sequentially transfers the stored image signals MPIX0 to MPIX8. At this time,
Peripheral image signals are simultaneously transferred along with the image signals to be transferred. The smoothing processing circuit 48 doubles the pixels in the main scan and the sub-scan from the transferred image signals MPIX0 to MPIX8 twice. At this time, the signal e becomes “0”
When the signal e is "1", smoothing for a photographic image is performed, and the processed image signals SPIX0 to SPIX3 are sequentially transferred to the recording unit 49. The recording unit 49 stores image signals SPIX0 to SPIX3 for one page.
Are stored sequentially, and the storage circuit 45 transfers the read end signal REND to the control unit 50 when all the stored data is transferred.
Is output. The control unit 50 outputs a read end signal REND
Is input, a recording start signal PSTR is output to the recording unit 49, and the recording unit 49 records the stored image signal. When the recording is completed, the control unit 50 sends a recording end signal PE
ND is output, and the control unit 50 ends a series of operations.

As described above, according to the fourth embodiment, the received encoded data amount is detected, and the obtained encoded data amount is averaged by the number of lines to obtain an average encoded data amount.
The average encoded data amount is compared with a preset reference value E. If the average encoded data amount is smaller than the reference value E, the received data is determined as character image data, and if the average encoded data amount is larger than the reference value E, it is determined as photographic image data. Therefore, it can be determined whether there is a large amount of character image data or a large amount of photographic image data in one document, and pixel enlargement can be performed for each document by an interpolation method suitable for each image data.

In the fourth embodiment, the character image and the photographic image are distinguished from the average encoded data amount per line in each document. The determination may be made from the average value of the data amount. Also, one page or one page regardless of each document
Both may be determined from the average encoded data amount for each line.

(Embodiment 5) Next, a fifth embodiment of the present invention will be described with reference to FIG. In FIG. 9, a line control circuit 51 is connected to a communication line LINE and performs a series of controls such as starting communication with an external facsimile terminal, data transfer, and communication. A decoding circuit 52 decodes the coded data transferred from the line control circuit 51 and converts the coded data into print data. 53 is a timer for measuring the communication time. A line counter 54 counts the number of print data lines. An average value calculation circuit 55 calculates the average communication time per line by dividing the measured value b of the timer 53 by the number of lines a of the line counter 54. Reference numeral 56 denotes a comparator which compares a preset reference value F with an average communication time value c output from the average value calculation circuit 55, and outputs "0" when the reference value F> the average communication time value c. Is set, and when the reference value F ≦ the average communication time value c, the output d is set to “1”. A storage circuit 57 temporarily stores the print data output from the decoding circuit 52 and the output d of the comparator 56. Reference numeral 58 denotes a smoothing processing circuit which performs smoothing for a character image when the output e of the storage circuit 57 is "0", and performs smoothing for a photographic image when the output e is "1". A recording unit 59 has a built-in storage circuit for storing one page of recording data, and records according to the recording data. Reference numeral 60 denotes a control unit that controls the above units. The ROM table for generating the reference value F is the same as that of the first embodiment described above, and includes three values of an x value indicating the encoding method, a y value indicating the format size, and a z value indicating the linear density. A reference value F is determined from the elements.

Next, the operation of the fifth embodiment will be described. First, the control unit 60 outputs a clear signal CLR to clear each circuit. The line control circuit 51
When a communication start signal is received from a communication terminal such as a facsimile (not shown) via the communication line LINE, the communication signal L
CON is enabled and output to the control unit 60. Next, when data transfer for one page is received, a page signal PAGE indicating that one page of data is being transferred is enabled and output to the control unit 60, and the decoding start signal D is sent to the decoding circuit 52.
Output STR. The decoding circuit 52 receives the clock DCL
Upon receiving the encoded data DATA transferred in synchronization with K, when the transfer of one page of data is completed, the valid section signal DENB is invalidated. When the page signal PAGE is input, the control unit 60 sends the clear signal TC to the timer 53.
In addition to outputting LR, the timer 53 outputs a time measurement signal TSTR, and the timer 53 starts measuring time in response to this. When the valid section signal DENB becomes invalid, the control unit 60 outputs a decoding start signal DSTR to the decoding circuit 52. When the decoding start signal DSTR is input, the decoding circuit 52 starts decoding the sequentially transferred encoded data DATA, and also stores the valid section signal LENB, the clock PCLK, and the image signal in the storage circuit 57 line by line. Output PPIX. The storage circuit 57 sequentially stores the transferred image signals PPIX. The line control circuit 51
When a transfer end for one page is known from a communication terminal such as a facsimile (not shown), the page signal PAGE is invalidated. The control unit 50 outputs a decoding start signal DSTR,
The line counter 54 sequentially counts the number of valid section signals LENB. When the decoding circuit 52 detects the end of the data from the transferred encoded data, it outputs a decoding end signal DEND to the control unit 60. The average value calculation circuit 55 calculates the measured value b of the timer 52 by the line number a of the line counter 54.
To calculate the average value of the communication time per line. The comparator 56 compares the preset reference value F with the average communication time value c output from the average value calculation circuit 55, and outputs “0” to the output d when the reference value F> the average communication time value c. Set “1” to the output d when the reference value F ≦ the average communication time value c. The control unit 60
The latch signal LATH is output to the storage circuit 57 and the comparator 5
6 is latched, and the storage circuit 57 stores the output signal d of the comparator 56 corresponding to the currently processed data of one page. Next, upon receiving data transfer of the next one page from a communication terminal such as a facsimile (not shown), the page signal PAGE is invalidated, and when the data transfer is completed, the communication signal LCON is invalidated. The control unit 60 repeats the above operation until the in-communication signal LCON becomes invalid. When invalidating the in-communication signal LCON, the control unit 60 outputs a read start signal RSTR to the storage circuit 57. Upon receiving the read start signal RSTR, the storage circuit 57 sequentially transfers the stored image signals MPIX0 to MPIX8 to the smoothing processing circuit 58. At this time, the peripheral image signal is also transferred together with the image signal to be transferred. The smoothing processing circuit 58 outputs the transferred image signal MP
From IX0 to IX, 2 for each of main scanning and sub-scanning
The pixel is enlarged twice. At this time, when the signal e is "0", smoothing for a character image is performed, and when the signal e is "1", smoothing for a photographic image is performed.
PIX0 to PIX3 are sequentially transferred to the recording unit 59. Recording section 59
Sequentially stores the image signals SPIX0 to SPIX for one page. On the other hand, when all the stored data is transferred, the storage circuit 57 outputs a read end signal REND to the control unit 60. When receiving the read end signal REND, the control unit 60 outputs a recording start signal PSTR to the recording unit 59, and the recording unit 59 records the stored image signal.
When the recording is completed, a recording end signal PEND is sent to the control unit 60.
Is output, and the control unit 60 receives the notification and ends a series of operations.

As described above, according to the fifth embodiment,
Detects the communication time required to receive the received data of one document,
The obtained communication time is averaged by the number of lines to obtain an average communication time. The average communication time is compared with a preset reference value F. If the average communication time is shorter than the reference value F, the received data is converted to a character image. Since it is determined that the data is large, and if the number is large, it is determined that the image data is photographic image data.
Pixel enlargement can be performed for each document by an interpolation method suitable for each image data.

In the fifth embodiment, the character image and the photographic image are discriminated from the average value of the communication time per line for each document. However, the communication time is not limited to one line but every N bits. May be determined from the average value of. Further, the character image and the photographic image may be determined based on the communication time for each page or each line, not just for each document.

In each of the above embodiments, the pixel expansion in the smoothing processing circuit is 2 × 2. However, the present invention is not limited to this. Having. Further, when the counting of the number of lines is performed by the valid section signal LEND of one line, instead of this, in the case of MH and MR code data, EOL is detected from this data and the number of lines is obtained from the number. Is also good.

[0042]

As is apparent from the above description, the present invention focuses on the fact that the received encoded data amount differs between the character image data and the photographic image data, and the decoding time or the encoded data amount or the communication By comparing the time with a preset reference value, it is determined whether the received data is character image data or photographic image data. By determining the data in units of lines or N bits, it is possible to determine whether the image data is character image data or photographic image data for each unit. Pixel enlargement is performed by a method suitable for each image data. A clear and good-looking recorded image can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an image receiving apparatus according to a first embodiment of the present invention.

FIG. 2 shows an RO for generating a reference value according to the first embodiment;
Schematic diagram showing the M table

FIG. 3 is a block diagram illustrating a schematic configuration of a smoothing processing circuit according to the first embodiment;

FIG. 4 is a schematic diagram showing an example of enlarged pixels in the first embodiment.

FIG. 5 is a schematic diagram showing an example of ROM data of a smoothing processing circuit according to the first embodiment;

FIG. 6 is a block diagram illustrating a schematic configuration of an image receiving apparatus according to a second embodiment of the present invention.

FIG. 7 is a block diagram illustrating a schematic configuration of an image receiving apparatus according to a third embodiment of the present invention.

FIG. 8 is a block diagram illustrating a schematic configuration of an image receiving apparatus according to a fourth embodiment of the present invention.

FIG. 9 is a block diagram illustrating a schematic configuration of an image receiving apparatus according to a fifth embodiment of the present invention.

FIG. 10 is a block diagram showing a schematic configuration of a conventional facsimile machine.

FIG. 11 is a block diagram showing another schematic configuration of a conventional facsimile machine.

FIG. 12 is a block diagram illustrating a schematic configuration of a conventional image receiving apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Decoding circuit 2 Timer 3 Line counter 4 Average value calculation circuit 5 Storage circuit 6 Comparator 7 Latch circuit 8 Smoothing processing circuit 9 Recording unit 10 Control unit 11 ROM table storing reference value 12 ROM in smoothing processing circuit 21 Decoding Conversion circuit 22 timer 23 comparator 24 counter 25 storage circuit 26 comparator 27 latch circuit 28 smoothing processing circuit 29 recording unit 30 control unit 31 decoding circuit 32 timer 33 comparator 34 storage circuit 35 smoothing processing circuit 36 recording unit 37 control unit 41 decoding circuit 42 data amount detection circuit 43 line counter 44 average value calculation circuit 45 storage circuit 46 comparator 47 latch circuit 48 smoothing processing circuit 49 recording unit 50 control unit 51 line control circuit 52 decoding circuit 53 timer 54 line cow Counter 55 average value calculation circuit 56 comparator 57 storage circuit 58 smoothing processing circuit 59 recording unit 60 control unit

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H04N 1/40 H04N 1/387 101 H04N 1/41-1/419

Claims (4)

(57) [Claims] 1. A means for measuring a total time required for decoding received encoded data, and averaging the total decoding time obtained by the measurement by the number of lines or the number of bits to obtain an average decoding time. judging means, the comparison with the average reference value predetermined decoding time, the average when the decoding time is shorter relative to the reference value determines the received data and character image data is longer than the photographic image data Means to
The character image data is smoothed for the character image data.
Processing, and the photographic image data
An image receiving apparatus comprising: a smoothing processing unit that performs a smoothing process . 2. A means for measuring the time required for decoding received encoded data for each line or every N bits, and comparing the unit decoding time obtained by the measurement with a preset reference value. Means for counting the number of times when the unit decoding time is long with respect to the reference value, and comparing the number of times with another preset reference value. Means for determining the image data if the number is large,
For the character image, perform the smoothing process for the character image, and
Smoothing processing for photographic images for photographic image data
Image receiving apparatus and a smoothing processing means for performing. 3. A means for measuring the time required for decoding the received encoded data for each line or every N bits, and comparing the unit decoding time obtained by the measurement with a preset reference value. , Line unit or N bit unit
Wherein when the unit decoding time is shorter, it is determined that the character image data, long when photographic image data and determine the relative said reference value
And a character image for the character image data.
For the photographic image data
Processing to perform smoothing processing for photographic images
Image receiving device and a physical means. 4. A or per line of the received encoded data
Or means for measuring the amount of received data per N bits ;
Compared with a reference value set in advance the amount of received data, if the received data amount is smaller than the reference value, it is determined that the character image data, if often determines that the photographic image data
Means and a character image sum for the character image data.
Photographic processing, and the photographic image data is
Smoothing processing means for performing smoothing processing for true images
Image receiver including and.