JPH11177829A - Facsimile reception terminal equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily discriminate whether it is the quality degradation of a transmission line or the abnormality of a terminal while minimizing influence on reception reproduction images. SOLUTION: In this facsimile reception terminal equipment for outputting received code image data from a code image data output part 11 to a decoding processing part 12, outputting image data at the time of normal decoding from a line output part 13 and outputting the image data from a line memory 14 holding the image data at the time of normal decoding from the line output part 13 instead of the image data of a decoding error generated line when a decoding error is generated, constitution for inverting the dot of the right end or left end of the image data written to the line memory 14 or the image data read from the line memory 14 is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facsimile receiving terminal capable of displaying transmission error information of a facsimile signal on a facsimile output image.

[0002] A facsimile signal is encoded by a code such as an MH code (modified Huffman code) on the transmission side and transmitted as coded image data. On the reception side, the received facsimile signal (coded image data) is decoded (decoded).
The created image data is input to a printer or a display device, and is printed out or displayed.

[0003] As in general data transmission, transmission errors may occur in the transmission of encoded facsimile signals. When such a transmission error occurs, normal decoding cannot be performed on the receiving side. In that case, the received and reproduced image contains an error, and the image quality is degraded. It is desired to display such a state without affecting the received and reproduced image.

[0004]

2. Description of the Related Art FIG. 4 is an explanatory diagram of a conventional facsimile receiving terminal device. 41 is a code image data output unit, 42 is a decode processing unit, 43 is a line output unit, 44 is a line memory, and 45 is a line copy unit.

[0005] The code image data output section 41 receives the facsimile signal transmitted from the transmission side and outputs it to the decode processing section 42 as code image data. Decode processing unit 42
Decodes (decodes) code image data,
It is determined whether or not decoding has been completed normally. If the decoding has been completed normally, the decoded image data is sent to the line output unit 43.

The line output unit 43 is provided with a decode processing unit 42
Is output to a printing / display unit (not shown), and the one-line image data is
Output to the line memory 44. The line memory 44 has 1
Each time the processing of the image data for the line is completed, the image data is overwritten by the image data from the line output unit 43.

When a decoding error occurs in the decoding processing section 42, a decoding error signal is output to the line copying section 45. Since the coded image data has been run-length coded or variable-length coded, if a transmission error occurs, the original image data cannot be restored.

[0008] The line copy unit 45 includes the decode processing unit 4
When a decode error signal is input from the line 2, the image data for one line at the time of normal decoding held in the line memory 44 is read, and the image data for one line is sent to the line output unit 43.

The line output unit 43 converts the image data of one line at the time of occurrence of a decoding error into the one at the time of the previous normal decoding.
It is output by replacing it with the line image data. Utilizing the relatively large correlation between the image lines and using the image data from the previous normal decoding without using the image data when a decoding error occurs, the image quality of the received / reproduced image is reduced. can do.

FIGS. 5A and 5B show an outline of the above-described conventional decoding error occurrence. FIG. 5A shows a decoding error occurrence position of image data, and FIG. 5B shows image data output from the one-line output unit 43. Is shown. Black squares represent image data printed / displayed as dots, indicating a substantially triangular image, and (A) 'XXX... XX
X 'represents a line where a decoding error has occurred.
L1 is the image data of the line immediately before the decoding error occurs.

[0011] As shown in FIG.
Assuming that a decode error has occurred at the location XXX ', the line copy unit 45 reads out the image data L1 of the line immediately before the decode error occurrence from the line memory 44 by the decode error signal from the decode processing unit 42, and The data L1 is sent to the line output unit 43.

The line output section 43 replaces the image data of the line in which the decoding error has occurred with the image data L1 of the line immediately before the occurrence of the decoding error and outputs the data, thereby preventing the deterioration of the image quality of the received reproduced image due to the decoding error. doing.

When image data output from the line output unit 43 is printed and displayed, as shown in FIG. 5B, the location where a decoding error occurs is the same line as the immediately preceding line L1, so that Facsimile recipients can print and receive
From the displayed image, it can be inferred to some extent that an abnormality has occurred in the received image.

[0014]

However, the abnormality of the facsimile reception image as described above is caused by the occurrence of a decoding error due to the deterioration of the transmission path quality (transmission error) or the facsimile reception terminal device itself, for example. It is difficult to determine whether the problem is caused by a defect in the printing / display unit or the like.

Therefore, when a decoding error due to deterioration in the quality of the transmission path is detected, image data of a specific pattern is forcibly inserted into a decoding error generating line, and the specific pattern is added to a received / reproduced image. A method that allows the image receiver to determine the deterioration of the transmission path quality is conceivable, but such a method affects the outline and outer shape of the transmitted image itself, making the image difficult to see, In some cases, there is a problem that the content of the image itself cannot be determined.

According to the present invention, a facsimile receiving terminal device capable of easily determining whether the quality of a transmission path is deteriorated or the terminal is abnormal while minimizing the influence on a printed / displayed image. The purpose is to provide.

[0017]

According to the present invention, there is provided a facsimile receiving terminal apparatus comprising: (1) a decode processing unit for decoding a received facsimile signal; Is replaced with the normally decoded image data held in the line memory 14, and a line output unit 13 for inverting and outputting the right end or left end dot of the line is provided. Therefore, when a decoding error based on a transmission error occurs, the rightmost or leftmost dot is inverted to white or black and output.

(2) It is possible to provide a dot inverting section 16 for inverting the right or left dot of the line of the image data to be written into the line memory 14 at the time of normal decoding.

(3) The line memory 14 holds the image data at the time of normal decoding, and inverts the right or left dot of the line when outputting the image data to the line output unit 13 when a decoding error occurs. A reading configuration can be adopted.

(4) A configuration may be provided in which the number of inverted dots at the right end or the left end of the line of the image data to be written to or read from the line memory 14 is selected and set.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view of a main part of a facsimile receiving terminal apparatus according to an embodiment of the present invention. 11 is a code image data output unit, 12 is a decode processing unit, 13 is a line output unit, 14 is a line memory, 15 is a line copy unit,
Reference numeral 16 denotes a right end dot inversion unit.

The code image data output unit 11 receives a facsimile signal from the transmission side, that is, code image data, and outputs the code image data to the decode processing unit 12. The decode processing unit 12 decodes (decodes) the encoded image data, determines whether or not the decoding has been normally completed, and when the decoding has been normally completed, sends the decoded image data signal to the line output unit 13. Send out.

The line output unit 13 is connected to the decode processing unit 12
Is output to a printing / display unit (not shown), and the one-line image data is
Output to the right end dot inversion unit 16.

The right end dot inverting section 16 is connected to the line output section 1
3 is output to the line memory 14 by inverting the right-hand dot of the image data for one line from black and white. The dot to be inverted by the right end dot inversion unit 16 is 1
It can be set as an arbitrary number of dots as described above.

The line memory 14 is overwritten each time the processing of the image data signal for one line is completed, ie, the right end dot of the image data from the line output unit 13 at the time of normal decoding is inverted by black and white. Then, one line of image data is held.

In the decoding processing unit 12, when a decoding error occurs due to an error in the code image data output from the code image data output unit 11, a decoding error signal is output to the line copy unit 15.

The line copy unit 15 is provided with the decode processing unit 1
When a decode error signal is input from the line 2, the image data for one line stored in the line memory 14 is read out, and the image data for one line is sent to the line output unit 13.

The line output unit 13 includes a line copy unit 15
When the image data for one line is input from, this image data is output. That is, instead of the image data in which a decoding error has occurred, the image data of the immediately preceding normal decoding is output again. At this time, since the right end dot of the line is inverted between black and white, it is possible to identify that a decoding error has occurred by observing the output image. In this case,
The decoding error signal is also input to the line output unit 13,
The line output unit 13 can also perform selective output control of image data from the decode processing unit 12 and image data from the line copy unit 15.

The right end dot inverting section 16 inverts the right end dot of one line of image data.
The image at the time when the image data read from the line is output from the line output unit 13 is obtained by inverting the black and white at the right end of the line immediately before the line where the decoding error has occurred. The right end dot inversion unit 16 can be a dot inversion unit for inverting the left end dot of the line. In this case, the output image is obtained by inverting the left and right black and white of the line immediately before the decoding error occurrence line. It will be.

Therefore, when a decoding error occurs, an image including one dot or a plurality of dots including black-and-white inversion is output to the right end or the left end which does not affect the reception / reproduction image quality, and a decoding error based on a transmission error can be displayed.

FIG. 2 is an explanatory diagram of an image data signal when a decoding error occurs according to the embodiment of the present invention. 3A shows a position where a decoding error has occurred in image data, and FIG. 3B shows image data output from the line output unit 13. In the figure, black squares indicate black dots of the output image, and 'XXX ... XXX' indicates a line where a decoding error has occurred. L1 is the image data of the line immediately before the occurrence of the decoding error, and L1 'is the image data of the rightmost dot of the image data of the line immediately before the occurrence of the decoding error, which is black and white inverted.

As shown in FIG. 2A, 'XXX...
Assuming that a decode error has occurred at the location of XXX ', the line copy unit 15 reads the dot at the right end of the image data of the line immediately before the occurrence of the decode error from the line memory 14 by the decode error signal from the decode processing unit 12. The image data L1 ′, which has been inverted in black and white, is read out, and the image data L1 ′ is sent to the one-line output unit 13.

The line output unit 13 replaces the image data of the line in which the decoding error has occurred with the image data L1 'obtained by inverting the right end dot of the image data of the line immediately before the decoding error in black and white.

When the image data output from the line output unit 13 is printed and displayed, as shown in FIG. 2B, the location where the decoding error has occurred is the same line as the immediately preceding line L1. Since the right end is the black and white inverted version of the right end of the previous line, the facsimile image receiver must determine from the printed / displayed image that a decoding error has occurred due to the black and white inverted state of the right end. Can be.

FIG. 3 shows a circuit configuration of the facsimile receiving terminal device according to the embodiment of the present invention. In the figure, 31 is a processor (CPU), 32 is a decode processing unit, 33 is a work memory, 34 is a parallel / serial conversion unit, 35
Is a decoded line copy unit, 36-1 is a first line memory, 36-2 is a second line memory, 36-3 is a third line memory, 37 is a right end dot inversion control unit, 3
8 is a line memory selection unit, and 39 is a changeover switch.

A facsimile signal transmitted from the transmitting side,
That is, the encoded image data is sent to the decode processing unit 32 via the CPU 31. The decode processing unit 32 decodes the encoded image data, and the decoded image data is temporarily stored in the work memory 33 and then switched from the work memory 33 via the parallel / serial conversion unit 34 by the changeover switch 39. The first line memory 3
6-1 and the second line memory 36-2 are alternately stored. That is, the first and second line memories 36-1, 36
-2 operates as a double buffer configuration in which image data is written to one side and image data is read out from the other. The changeover switch 39 is controlled by the CPU 31 together with the parallel / serial converter 34.

The third line memory is a buffer memory in which image data at the time of normal decoding is always overwritten by the decoded line copy unit 35, and is written by the right end dot inversion control unit 37 at the time of writing or reading. Control is performed so that the rightmost dot is inverted. Such a control structure can be easily realized by a logic circuit or software processing for identifying the right end and inverting the dot in black and white, for example, since the head and the tail of one line can be identified.

When the decoding processing unit 32 detects the occurrence of a decoding error, it notifies the CPU 31 of the decoding error, and the CPU 31 controls the selection signal of the line memory selection unit 38 and is held in the third line memory 36-3. Output the image data.

When a decoding error occurs and the third line memory 36-3 is selected under the control of the CPU 31 to output the held one-line image data, the dot at the right end of this image data is inverted. Therefore, at the right end of the line corresponding to the decoding error occurrence of the output image, when the right end of the immediately preceding line is a white dot, the image is inverted to a black dot, and when the right end of the previous line is a black dot, an image inverted to a white dot is output. .

Further, since the decoding error occurrence line is replaced with the previous line, it hardly affects the shape and contour of the image, and the occurrence of the decoding error can be displayed by minute black and white inverted dots. .

Normally, a decoding error occurs rarely due to a defect in the facsimile receiving terminal itself, and in most cases, transmission quality deteriorates. Therefore, by adding a means for inverting and displaying the right end dot at the time of detecting the occurrence of the decoding error, it is possible to easily determine the abnormality of the transmission quality and the trouble of the facsimile receiving terminal device itself.

In the embodiment of the present invention, the effect on the image itself is only the dot at the right end, so that it is slight in the entire image, and the right end is not used in a normal image pattern. Although the influence is extremely small and negligible, the quality of the transmission path can be easily grasped visually by the number of dots at the right end.

In the above-described embodiment of the present invention, when a decoding error occurs, the rightmost dot of the image is inverted between black and white. However, the rightmost dot inversion control unit 37 controls the dot inversion control to invert the leftmost dot. By inverting the left end dot of the image data to be written in the third line memory 36-3,
3, the left end dot can be inverted when the image data is read. The number of inverted dots at the right end or the left end can be set as an arbitrary number of dots. That is, in the case where one dot is very small, when the inversion of one dot cannot be determined from the output image, the number of inverted dots can be set to a plurality of dots, and the occurrence of a decoding error can be determined based on the output image. Further, the decoding processing unit 32 can be realized by the processing function of the processor (CPU) 31.

A decoding error is a bit error caused by a transmission error, and is caused by coded image data different from the coding rule. The frequency of occurrence of such a transmission error can be checked by a received and reproduced image. a. Therefore, the transmission quality of the facsimile signal can be determined by observing the received and reproduced image.

In addition, since the transmission quality often changes randomly for each call, if the receiver identifies the deterioration of the transmission quality, the receiver notifies the sender of a retransmission request for a facsimile image, thereby allowing the receiver to perform normal operation. Facsimile reception processing can be performed.

[0046]

As described above, according to the present invention,
Inverts the rightmost (or leftmost) dot of the image data output from the line memory for replacement processing when a decoding error occurs, and outputs it by checking the output image just by looking at the output image. can do. Thereby, the transmission quality state can be grasped, and it can be easily determined whether the quality of the transmission path is deteriorated or the terminal is abnormal.

Further, since the black and white inversion of only the right end (or left end) dot is performed, the influence on the output image itself is extremely small, and the influence on the printed / displayed image is minimized, so that the image quality is impaired. Never be.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a main part of a facsimile receiving terminal device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of an image data signal when a decoding error occurs according to the embodiment of the present invention.

FIG. 3 is a diagram showing a circuit configuration of the facsimile receiving terminal device according to the embodiment of the present invention.

FIG. 4 is an explanatory diagram of a conventional facsimile receiving terminal device.

FIG. 5 is an explanatory diagram of a conventional image data signal when a decoding error occurs.

[Explanation of symbols]

 11 Code image data output unit 12 Decoding processing unit 13 Line output unit 14 Line memory 15 Line copy unit 16 Right end dot inversion unit

Claims (4)

[Claims] A decoding unit for decoding a received facsimile signal; and when a decoding error occurs in the decoding unit, replacing the image data in which the decoding error has occurred with image data of a normal decoding held in a line memory.
A facsimile receiving terminal device comprising: a line output unit for inverting and outputting a right end or left end dot of a line. 2. The facsimile receiving terminal device according to claim 1, further comprising a dot inverting section for inverting a right end or a left end dot of a line of image data written in the line memory at the time of normal decoding. 3. A configuration in which the line memory holds image data at the time of normal decoding, and inverts and reads a dot at a right end or a left end of a line when outputting the image data to the line output unit when a decoding error occurs. 2. The facsimile receiving terminal device according to claim 1, comprising: 4. The facsimile receiving apparatus according to claim 2, wherein the number of inverted dots at the right end or the left end of a line of image data to be written to or read from the line memory is selected and set. Terminal device.