JPS58173976A - Facsimile communication method - Google Patents

Abstract

PURPOSE:To decrease the transmission time and to improve the fidelity of a reception picture to an original picture, by omitting at each other line, the transmission of picture information at the transmission side and recording each picture element of lines omitted for the transmission by means of a series of algorithm at the reception side. CONSTITUTION:The 1st and the 3rd line of picture information is inputted to registers 7, 8 from line registers 3, 4 respectively, white information (''0'') shared for one line is inputted from white picture information generating circuits 5, 6, and the 5th and the 3rd line of picture information is inputted from the line registers 3, 4 respectively, and further, white picture information shared for one line is inputted from the white picture information generating circuits 5, 6. Thus, the picture information of the (2m-1)-th line and the (2n+1)-th line (where n=1, 2, 3,...) and the white picture information shared for one line are inputted alternately. The information is outputted to an ROM9 sequentially, and the ROM 9 inputs the picture information for the noted picture determined with the algorithm basing on the picture information to a line register 10.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a facsimile communication system, and more particularly to a facsimile communication system in which the sending side omits the transmission of image information every other line.

This type of facsimile communication method is implemented for the purpose of shortening the transmission time when transmitting coarse parts of the image, etc., but in the conventional facsimile communication method of this type (called recirculate method), , on the receiving side, the same image information as the line immediately before it was recorded for the line whose transmission was omitted.

Therefore, when a document as shown in Fig. 1 is sent, in normal facsimile communication in which the sending side sends image information for all lines, the receiving side obtains a received image as shown in Fig. 2; With the conventional NoriSarky rate method, a received image like the one shown in Figure 3 is obtained (in Figures 1 to 3, one square represents one pixel, and the shaded area represents the received image). The dotted portion in Figure 1 is always a black pixel in Figures 2 and 3, and the white blank area is a peak of 3 b/min in Figure 1 and is a white pixel in Figures 2 and 3.-! ,Ta,
The numbers on the left side of each figure and the alpha beneau numbers on the L side of each figure.
are written in order to make each pixel symmetrical with these combinations).

As is clear from comparing FIG. 3 with FIG. 2, in the conventional recirculating method, in the received image, pixels 2a, 4C, and 6e, which should originally be white pixels, become black pixels; Pixels 2d, 4f, 6h that should be
This has the drawback that the received image becomes a white pixel, and the fidelity of the received image with respect to the original image (FIG. 1) deteriorates significantly.

The present invention has been made in order to eliminate the above-mentioned drawbacks of the conventional art, and reduces the transmission time by omitting the transmission of image information every other line on the transmitting side, and improves the fidelity of the received image with respect to the original image. 0,1. ,.

The facnomy communication system according to the present invention does not simply record the same image information as the line immediately before the line for which the sending side has omitted transmission, as in the conventional method, but uses the image information of the line immediately before it and the image information immediately after it. The image information determined by taking into consideration both the image information of the line and the image information of the line is recorded.

Hereinafter, the present invention will be explained in more detail using the drawings.

In the present invention, as shown in FIGS. 4 to 6,
Whether pixel A of interest in a line that was not transmitted on the sending side is recorded as a black pixel or a white pixel is determined by pixel B and pixel B that are the same in the main scanning direction as pixel A of interest in the line just before it. The three pixels before and after it, pixels C and D,
The pixel A of interest in the immediately following line, the same pixel E in the main scanning direction, and the three pixels F and G before and after it,
It is determined based on a total of six pixels using the algorithm described below.

That is, in FIG. 4, the three pixels B and C of the immediately previous line are
, D, and the pattern of image information composed of the three pixels E, F, and G of the immediately following line are the same. There is. Among these, when pixels B to G are all white pixels in 6 basis as in (7), there is a high probability that the pixel of interest A sandwiched between these white pixels will also be a white pixel.

In the case of ox, (a) ~ (Shu, each black pixel has a high probability of forming a line extending in the sub-scanning direction. Therefore,
(a) ~ (As shown in the gradient, if pixels B and E are white pixels, there is a high probability that the pixel of interest A is also a white pixel; on the other hand, (4
) to shi), when pixels B and E are black pixels, there is a very high probability that the pixel of interest A is also a black pixel.

Therefore, in the present invention, as shown in FIG. If so, the pixel of interest A is recorded as the same type of pixel as pixels B and E. That is, if pixels B and E are white pixels, they are recorded as white pixels, and if pixels B and E are black pixels, they are recorded as black pixels.

Next, FIG. 6 shows three pixels B in the line immediately after the above.

・The image information consisting of C and D (turn and the above 6
The image information pattern consisting of three pixels E, F, and G on the line immediately before the page is not the same, and pixels B, C, and D are all white pixels, or pixels E, F, and G are all white pixels. It shows all the patterns when .

In the case of FIG. 5, the probability that the pixel of interest A becomes a black pixel consecutively in the sub-scanning direction or (and) the diagonal direction is small compared to the black pixels among the pixels B to G.

Therefore, in the present invention, in the case of FIG. 6, the pixel of interest A is recorded as a white pixel.

Next, in FIG. 6, the pattern of image information made up of pixels B, C, and D is not the same as the pattern of image information made up of pixels E, F, and G, and pixels B, C, and D A typical example is shown in which there is one or more black pixels in each of pixels E, F, and G.

In the case shown in FIG. 6, the pixel A of interest is pixel B-
There is a high probability that black pixels in G will be consecutive black pixels in the sub-scanning direction and/or in the diagonal direction.

Therefore, in the present invention, in the case shown in FIG. 6, the pixel A of interest is recorded as a black pixel.

To summarize the above, in the present invention, the pixel of interest A is recorded using the following algorithm (,) to (c).

(a) When the pattern of image information made up of the three pixels B, C, and D in the immediately preceding line is the same as the pattern of image information made up of the three pixels E, F, and G in the immediately following line. are recorded as pixels of the same type as pixels B and E.

(b) The pattern of image information made up of the three pixels B, C, and D in the immediately preceding line is not the same as the pattern of image information made up of the three pixels E, F, and G in the immediately following line. , and if there is at least one black pixel in each of the three pixels B, C, and D of the immediately preceding line and the three pixels E, F, and G of the immediately following line, they are recorded as black pixels. .

(C) In other cases, it is recorded as a white pixel.

In addition, Fig. 4 (in the case of force, black pixels C, F and black pixels R, G
This means that there is a high probability that two lines in the sub-scanning direction are arranged side by side with an interval of about one pixel.

However, if the process (-) in the present invention is not performed and there is one or more black pixels in any of pixels B, C, D and pixels E, F, G, then pixels B, C ，
Even if the pattern of image information made up of D and the pattern of image information made up of pixels E, F, and G are the same, if the pixel of interest A is to be recorded as a black pixel, as shown in FIG. ), the pixel A of interest is also recorded as a black pixel, so in the received image, the line spacing in the sub-scanning direction is collapsed, making it impossible to faithfully reproduce these lines.

However, in the present invention, since the above-mentioned (-) processing is performed, such inconvenience does not occur.

FIG. 7 shows an embodiment of a facsimile receiver that implements the facsimile communication system of the present invention. 1 is an image information input terminal for inputting encoded image information; 2 is a decoding circuit; 3. )
4 is a line register that temporarily stores one line of image information, and 5 and 6 are self-drawing information (in this example, 0
9', 7.8 are 3-bit serial input/serial/parallel output noft registers, respectively.

9 is a ROM, and based on the image information of the pixels B to G input in parallel from the register 8, the (-) to (C)
It has a built-in conversion table that determines the pixel A of interest using the following algorithm. 10 is a line register that temporarily stores one line of round image information sent from the ROM 9;

11 is a switch, one of its two input terminals is connected to the output terminal of the decoding circuit 2, the other to the output terminal of the line register 3, and its output terminal is connected to the input terminal of the line register 3. has been done. 12 is also a switch, one of its two input terminals is connected to the output terminal of the decoding circuit 2, the other to the input terminal of the line register 4, and its output terminal is connected to the input terminal of the line register 4. has been done.

13 is also a switch, and one of its two input terminals is connected to the output terminal of the line register 3, and the other is connected to the output terminal of the self-image information generation circuit 5, and the output terminal is connected to the input terminal of the register 7. connected to the terminal. 14 is also a switch, one of its two input terminals is connected to the output terminal of the line register 4, the other to the output terminal of the self-image information generation circuit 6, and its output terminal is connected to the input terminal of the register 8. ing.

16 is a timing clock input terminal, and the decoding circuit 2, line registers 3, 4, registers 7.8, and line register 1o operate in synchronization with each other by the timing clock d input to this input terminal 15. .

However, a switch 16 is interposed between the timing clock input terminal 16 and the clock input terminals of the line registers 3 and 4.

17 is a switch, one of its two input terminals is connected to the serial output terminal of the register 7, and the other is connected to the serial output terminal of the register 8.

18 is also a switch, and one of its two input terminals is connected to the output terminal of the switch 17, the other to the output terminal of the line register 10, and its output terminal is connected to the image information output terminal 19. This image information output terminal 19 is connected to an input terminal of a recording section (not shown).

20 is an input terminal for the control signal e of the switches 11, 12, and 1, 21 is an input terminal for the control signal f of the switches 13 and 14, 22 is an input terminal for the control signal q of the switch 16, and 23 is a control signal for the switch 18. This is the second input terminal.

Next, the operation of this embodiment will be explained along with the time table shown in Table 1 (note that switch 11.1 in Table 1
2, 13, 14, 16, 17, and 18 states are shown in FIG. 8).

The switch 16 supplies the timing clock d to the decoding circuit 2 by turning it on for a certain period of time based on the control signal q.
is supplied to operate the circuit 2, and the encoded first line image information input to the image information input terminal 1 is sent to the circuit 2.
Stretch it to. Next, the switch 16 is turned off for a certain period of time corresponding to the second line of image information whose transmission was omitted by the transmitting side, and the decoding circuit 2 is stopped during this period. Subsequently, the switch 13 and switch 16 are turned on again for a certain period of time to cause the decoding circuit 2 to expand the encoded image information of the third line.

Similarly, the decoding circuit 2 operates by turning the switch 16 on and off at regular intervals.

The process repeats the stop and sequentially decompresses the odd-numbered encoded image information transmitted from the transmitting side.

The image information expanded by the decoding circuit 2 in this way is transferred to the line registers 3 and 4 by switches 11 and 12 controlled by the control signal e, which alternately connect the output terminals of the decoding circuit 2 to the line registers 3 and 4.
By connecting to the input terminal of , the first line goes to line register 3, the third line goes to line register 4,
The sixth line is input to line registers 3 and 4 alternately line by line (in Table 1, FIG. 8, and the following explanation, line registers 3, 4 The state in which the input terminals of are respectively connected to the output terminals of the decoding circuit 2 is expressed as the "input-enabled state".

Then, while the switch 11 sets the line register 3 to the 14''-digit "input enabled" state, the switch 12 connects the output terminal of the line register 4 and the input terminal of the same register 4, and The image information of the line inputted into the register 4 is input again to the same register 4 (in Table 1, FIG. 8, and the following explanation, this state is expressed as the "loop J state"). Conversely, while the switch 12 puts the line register 4 in the "input enabled" state, the switch 11 connects the output terminal of the line register 3 and the input terminal of the same register 3, and The image information of the input line is input again to the same register 3 (this state is also expressed as the "loop J state" in Table 1, FIG. 8, and the following explanation).

On the other hand, while the decoding circuit 2 is stopped due to the switch 16 being turned off as described above, the line register 3
, 4 are also stopped. And the switches 13 and 14 are
Based on the control signal f, during the stop period of the line register 3.4, the output terminals of the self-image information generation circuit 5.6 are respectively connected to the input terminals of the register 16 7.8 (Table 1, In Fig. 8 and the following explanation, this state is expressed as the "O output" state). Also, the same switch 13.14 is the switch 16
is on and line register 3.4 is operating, the output terminals of line register 3.4 are connected to the input terminals of register 7.80 (see Table 1, Figure 8, and the following F). In the explanation, this state will be expressed as a "one output possible" state).

However, the switches 13 and 14 are configured so that both the first line and the third line image information are stored in the line registers 3 and 4.
Until the state is set to 17, the state is set to 0 output J, instead of 17. Then, only after the image information of the first line and the third line are both stored in the line registers 3 and 4, the switch 160 is turned on and off in synchronization as described above, and the message "Output ready" is displayed. A state of "0 output" is realized alternately.

As a result of the above, first, the image information of the first line and the third line are inputted to the registers 7.8 from the line registers 3 and 4, respectively, and then the image information of the 1st line is inputted from the self-image information generation circuits 5 and 6.
The self-portrait information ("o'") for the line is input, then the image information for the 6th line and the 3rd line is input from the line register 3.4, respectively, and then the white image information generation circuits 5 and 6
One line of self-portrait information is input from each line register 3 and 4, and then the image information for the 5th line and 7th line is input from the line registers 3 and 4, respectively.
) line, (2n+1) line image information (where n=1.2.3, . . . ) and one line's worth of self-portrait information are alternately input.

Then, the register 7.8 inputs the image information of the (2n-1)th line and the (2n+1)th line serially inputted in this way, each with 3 bits, as the image information of the pixels B to G. Sequentially; output to ROM9. Based on the image information, the ROM 9 outputs image information for the pixel of interest A determined by the algorithm. And this RO
The output of M9 is input to line register 1o.

In addition, the image information of each line and 117.
- The reason why the self-portrait information for two lines is input alternately is that the first two pixels and the last two pixels of the even-numbered lines that were not transmitted by the sending side are respectively set as the pixel of interest A. , pixels B and C when deciding whether to use them as black pixels or white pixels.

This is because it is necessary to assume that E, F or pixels B, D, E, and G are white pixels (that is, it is the same as adding two white pixels to each end of an odd-numbered line). be.

On the other hand, switches 17 and 18 operate as shown in Table 1.

As a result, first, the expanded image information of the first line is outputted from the register 7 to the image information output terminal 19 through the switches 17 and 18. During this time, the image information of the second line created according to the algorithm is stored in the ROM.
9 to the line register 10, and further this second
The image information for the first line is output after the output of the image information for the first line from the register to the image information output terminal 19 is completed.
The image information is output from the register 10 to the image information output terminal 19 through the switch 18.

Page 18 Next, the expanded image information of the third line is output from the register 8 to the image information output terminal 19 through switches 17 and 18. During this time, the image information of the fourth line is input from the ROM 9 to the line register 10, and furthermore, the image information of the fourth line is input from the register 8 to the image information output terminal 19 of the third line. After the image information has been output, it is output from the register 1o to the image information output terminal 19 through the switch 18.

Subsequently, the expanded image information of the 6th line is stored in register 7.
The image information is output from the image information output terminal 19 to the image information output terminal 19, and the same operation is repeated thereafter.

Then, the recording section performs recording according to the image information of each line inputted from the image information output terminal 19.

As a result, for example, when a document as shown in Figure 1 is sent, the received image obtained on the receiving side will be the received image shown in Figure 2, which would be obtained in the case of normal facunmill communication in which all lines are transmitted without omitting them. , and the fidelity of the received image to the original image is significantly improved.

As described above, according to the present invention, it is possible to shorten the transmission time by omitting the transmission of image information every 12 to 19 frames on the transmitting side, and to improve the fidelity of the received image with respect to the original image. You can get excellent results.

[Brief explanation of the drawing]

Figure 1 is a diagram showing an example of a transmitted original, Figure 2 is a diagram showing a received image obtained by the conventional recirculating method when the transmitted original shown in Figure 1 is transmitted, and Figure 3 is a diagram showing all lines transmitted. Figures 4 to 6 show each pixel of the line whose transmission is omitted in the facsimile communication system of the present invention. Explanatory diagram showing an algorithm for determining whether to make a black pixel or a white pixel, 7th
The figure is a block diagram of a facsimile communication device according to an embodiment of the facsimile communication system of the present invention, and FIG. 8 is an explanatory diagram of the operating state of the valley switch in the same receiver. 8 - Pixel of interest in the line whose transmission was omitted, B. C, D----3 pixels of the previous line, E, F, G...
...-Three pixels of the line after 1M, 1--Picture information input terminal, 2--Decoding circuit, 3, 4--Line register, 5.6-- White screen information generation circuit, 7,
8...Shift register, 9...-ROM, I
C1-・Line register, 11.12, 13, 14,
16, 17.18 Switch, 19- Image information output terminal. Name of agent: Patent attorney Toshio Nakao and one other name
1 Figure 2 Figure 5 Figure 4 (a) l b)
t Uri song f ■ = loco A-j-, j ; r-i-ka FE & (shi) (zu) (se. (gi) (kutsu (tsuno (te) (to) ge)
C subfigure 6 (Pano (to Hino C)
(E)

Claims (1)

[Claims] The transmitting side omits the transmission of image information for every other line, and the receiving side transmits each pixel of the line whose transmission is omitted as follows (a):
A facsimile communication method that records data using the algorithms of (b) and (C). (a) An image information pattern consisting of the same pixel in the immediately previous line and the pixels before and after that pixel, and the same pixel in the immediately following line and the three pixels before and after it. If the patterns of image information made up of pixels are the same, the pixel is recorded as the same type of pixel as the same pixel in the immediately previous line and the immediately following line. (b) If the patterns of each of the image information are not the same, and there is one or more black pixels in both the three pixels of the immediately preceding line and the three pixels of the immediately following line, black Record as pixels. (C) In other cases, record as a white pixel. 2 pages