JP2549451B2 - Image signal processor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention is applied to an application field such as an image signal processing device for editing a screen, which is installed in an information center and is transmitted to a G4 facsimile machine. The present invention relates to an image signal processing device for M ² R encoding a raster format image signal.

[Conventional technology]

The end (EOFB = 00000000000100000000) of the encoded image signal that has been subjected to redundancy suppression encoding processing by the CCITT recommended M ² R encoding method.
The last bit of 0001) is generally not a byte boundary. Further, if the EOFB code is deleted from the encoded image signal Pm and the connection processing with another encoded image signal Qm is performed, a decoding error is generally generated, and a synthesized screen cannot be obtained.

Therefore, conventionally, the encoded image signal Pm and another encoded image signal
When combining Qm and 1 screen, coded image signals Pm and Qm
And are once decoded into original image signals (bit pattern format) Po and Qo, and then original image signals Po and Qo are connected to create a composite screen Ro = Po + Qo, and the composite screen image signal Ro is converted to M ²
R code was used to create a coded image signal Rm. For this reason, there is a drawback in that the processing overhead of once decoding the encoded image signals Pm and Qm and then re-encoding them occurs.

In order to eliminate these drawbacks, in JP-A-64-36267 "Facsimile transmitter", the EOFB signal from the encoded image signal is used.
A means for deleting the code and a means for inserting a coded image signal in which one search line is all white by using a horizontal mode code are inserted at page breaks, and a plurality of pages are maintained in the M ² R coded image signal format. The method of synthesizing on one page is disclosed.

FIG. 6 is an explanatory diagram of the processing method described above. First, the EOFB code is deleted from the encoded image signal Pm. Next,
The encoded image signal Wm in which one scanning line is all white is connected using the horizontal mode code. Next, another coded image signal Qm is connected. By the above processing, the encoded image signal Pm + Wm + Qm can be created.

[Problems to be Solved by the Invention]

However, in this method, the encoded image signals Pm to EO
There is a drawback that a decoding circuit (or decoding function) is required when deleting the FB code. In addition, when the encoded image signal Wm in which one scanning line is all white is connected to the encoded image signal Pm from which the EOFB code is deleted and when the encoded image signal Qm is connected to the encoded image signal Wm, the data is Is required at the bit boundary, so that if the connection processing is realized by software, the processing time becomes long (the dynamic step of the connection processing is large). In addition, a special codec is required to implement the connection processing by hardware, and a commercially available IC codec cannot be used. Alternatively, there is a drawback that additional hardware must be added to the commercially available IC codec.

In order to eliminate the above drawbacks, the present invention sets the end of the encoded image signal (the last bit of EOFB = 000000000001000000000001) as a byte boundary in advance, so that screen synthesis is performed by signal processing at the byte boundary instead of signal processing at the bit boundary. Realize that is possible.

[Means for solving the problem]

FIG. 1 is a diagram for explaining the creation of coded image signals and screen composition in the present invention. In the present invention, the encoded image signal Pm ′ = Pm + Wm + V (0) × N + EOFB in which a plurality of all-white scanning lines are added so that the encoded image signal Pm is on the byte boundary.
Create When synthesizing the screen of the encoded image signal Pm ′ and the encoded image signal Qm, the EOFB code of 3 bytes is deleted from the encoded image signal Pm ′ and the encoded image signal Qm is connected at the byte boundary. .

[Work]

In the present invention, as shown in FIG. 1, FIG. 4 and FIG. 5, the hardware processing of the encoding processing unit 44 is required when adding all white lines, but the subsequent processing, that is, Pm 'When
When the screen is combined with Qm, Pm + Wm + V (0) × N is a byte boundary, so that it can be processed by software processing of the control unit 43.

The original screen corresponding to the encoded image signal Pm and the encoded image signal Pm ′
The relationship with the screen corresponding to is shown in FIG. As shown in FIG. 2, the screen corresponding to the coded image signal Pm 'is the original screen corresponding to the coded image signal Pm to which blank lines from the minimum line to the maximum 9 lines are added.

〔Example〕

FIG. 3 shows an embodiment of a picture signal processing apparatus for realizing the present invention. In the figure, 41 is an image signal input / output terminal for inputting / outputting an image signal and an M ² R encoded image signal, 42 is a control signal input terminal for inputting a control signal, 43 is a control unit, 44 is an M ² R encoding process It is an encoding processing unit for performing. Here, the encoding processing unit 44 is a commercially available
It is composed of an IC codec (for example, HD63183), and the control unit 43 can instruct the presence / absence of EOFB code output. Further, when the internal encoded image signal buffer (1 byte) is full, the encoding processing unit 44 can transfer data to the control unit 43 and sends out an encoded image signal reception instruction signal. Next, the operation of the image signal processing device will be described with reference to FIGS. Note that FIG. 4 and FIG. 5 together show one flowchart, and show the correspondence between the control unit 43 and the encoding processing unit 44.

First, the control unit 43 receives an image signal (scanning line group consisting of bit pattern sequence of black = 1 / white = 0) Po in raster format from the image signal input terminal 41 (S1), and at the same time, receives the control signal input terminal.
A control signal instructing conversion from 42 to an M ² R encoded signal on a byte boundary is received (S2).

Next, the control unit 43 instructs initialization of the encoding processing unit 44 (S3), transfers the image signal Po to the encoding processing unit 44 (S4), E
Instructing M ² R coding process without OEB code (S5). The encoding processing unit 44 performs initialization (S21), receives the image signal Po (S22), performs M ² R encoding processing (S23), and the control unit every time the internal buffer becomes full (S24). The encoded image signal reception instruction signal is sent to 43 (S25). Then, the M ² R encoded image signal Pm is transmitted (S26). Next, the control unit 43 receives M ² R each time the encoded image signal reception instruction signal is received from the encoding processing unit 44 (S6).
The encoded image signal Pm is received (S7). At this point, the end (less than 1 byte) of the M ² R encoded image signal Pm may remain in the internal buffer of the encoding processing unit 44.

Next, the control unit 43 sends the image signal Wo whose one scanning line is all white to the encoding processing unit 44 (S8) and instructs the M ² R encoding process without the EOFB code (S9). The encoding processing unit 44 receives the image signal Wo whose one scanning line is all white (S27), performs M ² R encoding processing on the image signal Wo (S28), and fills the internal buffer (S29) every time. To the control unit 43, and sends an encoded image signal reception instruction signal (S3
0). Then, the process proceeds to the illustrated step (S31). Next, the control unit
43 receives the M ² R encoded image signal Wm each time the encoded image signal reception instruction signal is received from the encoding processing unit 44 (S10) (S1
1). At this point, in the internal buffer of the encoding processing unit 44,
The end (less than 1 byte) of the M ² R encoded image signal Wm may remain.

Next, the control unit 43 sends the image signal Wo of which one scanning line is all white to the encoding processing unit 44 (S12) and instructs the M ² R encoding process without the EOFB code (S13). The process is repeated until the encoded image signal reception instruction signal is received from the processing unit 44 (it is assumed that the process is repeated N times) (S14). Next, the encoding processing unit 44
Receives the image signal Wo of which one scanning line is completely white N times (S32), and creates the M ² R encoded image signal V (0) N times (S3
3) When the internal buffer is full (S34), the encoded image signal reception instruction signal is sent to the control unit 43 (S35). (S2
8) and (S33) are M ² R encoding processing of the all-white image signal, but the result obtained in (S28) corresponds to Wm in FIG. 1, and the result obtained in (S33) Corresponds to writing V (0) = 1 in the encoded image signal buffer (1 byte) inside the encoding processing unit 44 in response to the reception of Wo. The point is 1
The results of the Wo reception processing for the first time and the Wo reception processing for the second and subsequent times are different. Then, the process proceeds to step (S36). Next, when the control unit 43 receives the encoded image signal reception instruction signal from the encoding processing unit 44 (S14), the M ² R encoded image signal V (0) × N.
Is received (S15). At this point, the internal buffer of the encoding processing unit 44 becomes empty.

Next, the control unit 43 instructs the encoding processing unit 44 to send out the EOFB code (S16). Next, the encoding processing unit 44 creates an EOFB code (S37), and sends an encoded image signal reception instruction signal to the control unit 43 every time the internal buffer becomes full (S3).
8). Next, the control unit 43 receives the EOFB code every time the coded image signal reception instruction signal is received from the coding processing unit 44 (S17). EOFB code is EOL code (000000000001) x 2 =
Since it has a 3-byte structure (24-bit structure), at this point,
The internal buffer of the encoding processing unit 44 becomes empty.

Next, the control unit 43 sends the M ² R encoded image signal Pm ′ = Pm + Wm + V (0) × N + EOFB to the image signal input / output terminal 41.

By the above operation, the final scan line is the last byte boundaries are and EOFB code is all white line M ² R code Kaga signal P
m ′ is output to the image signal input / output terminal 41.

Next, the operation in the combining process of the M ² R encoded image signals created as described above will be described. First, the control unit 43 receives the M ² R encoded image signal Pm ′ and another M ² R encoded image signal Qm from the image signal input / output terminal 41, and at the same time receives the control signal input terminal 42.
From the control signal for instructing the screen synthesis of M ² R encoded Pm ′ and Qm.

Next, the control unit 43 controls the M ² R encoded image signal Pm ′ = Pm + Wm +
Delete the last 3 bytes of V (0) × N + EOFB. Since the EOFB code has a configuration of EOL code (000000000001) × 2 = 3 bytes, the EOFB code is deleted at this point, and the end of the M ² R encoded image signal Pm + Wm + V (0) × N becomes a byte boundary. Next, the control unit 43 adds the M ² R encoded image signal Qm (with EOFB), and the combined image signal Rm = Pm + Wm + V (0) × N.
Create ＋ Qm ＋ EOFB. In addition, the above-mentioned M ² R encoded image signal P
The process of deleting the EOFB code from m ′ and the M ² R encoded image signal Qm
The process of adding (with EOFB) is not a bit boundary process but a byte boundary process, so it can be easily implemented by software processing.

Next, the control unit 43 sends the M ² R encoded image signal Rm = Pm + Wm + V (0) × N + Qm + EOFB to the image signal input / output terminal 41.

With the above operation, the M ² R encoded image signal Rm
Is output to the image signal input / output terminal 41.

The notation "image signal A + B" used in the above description means that the image signal A and the image signal B are continuous.

〔The invention's effect〕

As described above, according to the present invention, since a commercially available IC codec can be used, there is an advantage that a special decoding circuit is unnecessary and the hardware configuration is simplified. Also,
Since it is possible to obtain M ² R encoded picture signals at byte boundaries,
It is possible to realize screen synthesis in the M ² R encoded image signal format with software. That is, there is an advantage that the last 3 bytes of the M ² R encoded image signal at the byte boundary can be deleted by software processing and combined with another M ² R encoded image signal.

The screen coded according to the present invention has a minimum of 2 lines and a maximum of 9 blank lines added to the original screen, as shown in FIG. However, considering that the scanning line density of the G4 facsimile terminal is about 8 to 16 lines / mm, the length of the blank line is about 1 mm or less, which is a negligible amount.

[Brief description of drawings]

FIG. 1 is a diagram for explaining the creation of an M ² R encoded image signal and screen synthesis according to the present invention, and FIG. 2 is a diagram for explaining the M ² R encoded image signal Pm and M ² R encoded image signal Pm ′ according to the present invention. FIG. 3 is a diagram showing an embodiment of an image signal processing device for realizing the present invention, FIGS. 4 and 5 are flow charts which together form a single diagram, and FIG. Japanese Patent Laid-Open No. 64-36267 “Facsimile transmitter” M ² R on a bit boundary
It is a figure explaining the connection processing system of a coded picture signal. 41 …… Image signal input / output terminal, 42 …… Control signal input terminal, 43…
... Control unit, 44 ... Encoding processing unit.

Claims (1)

(57) [Claims] 1. A processing function for performing M ² R encoding of an image signal and M
² R is an image signal processing device that performs processing by combining a control unit (43) and an encoding processing unit (44) by using a processing function of combining a plurality of screens of an encoded image signal format into one screen. A first portion that sends a raster format image signal Po and an M ² R encoding (without EOFB) instruction signal to the encoding processing unit, and waits for input of a reception instruction signal from the encoding processing unit; The reception instruction signal and the M ² R encoded image signal Pm from the encoding processing unit
Is received, the input of the next reception instruction signal is awaited,
If the input waiting time has elapsed for a predetermined time or longer, the second part that shifts to the third part, the all-white image signal Wo, and the M ² R encoding (without EOFB) instruction signal are encoded. A third portion which is sent to the processing unit and waits for the reception instruction signal from the encoding processing unit to be input, and the reception instruction signal and the M ² R encoded image signal Pm from the encoding processing unit.
Upon reception of the rest and M ² R code Kaga signal Wm, it waits for an input of the next received instruction signal, in the case where the input waiting has passed over a predetermined time period a fourth to move to the fifth portion
, And the all-white image signal Wo and the M ² R encoding (without EOFB) instruction signal are sent to the encoding processing unit, and the reception instruction signal from the encoding processing unit waits for input, and the reception instruction signal is received. Then, the process shifts to the sixth part, and when the input waiting has elapsed for a predetermined time or more, a fifth part to be executed from the beginning of the fifth part and a reception instruction signal from the encoding processing part. When receiving the rest, the rest of the M ² R encoded image signal Wm and the M ² R encoded image signal V (0) × N are received, and the EOFB code transmission instruction is transmitted to the encoding processing unit.
And a seventh part for receiving the EOFB code, the encoding processing unit performs M ² R encoding based on the received raster format image signal Po and the encoding instruction signal, and the internal buffer is M Each time the ² R encoded image signal is full, the reception instruction signal and the M ² R encoded image signal P
If m is sent to the control unit and the internal buffer is not full due to the end of the M ² R encoded image signal, the eighth part waiting for input of the all-white image signal Wo and the received all-white image M ² R based on signal Wo and coding instruction signal
Performs encoding, when the internal buffer is full by M ² R code Kaga signal, sent to the control unit together with the received instruction signal remaining and M ² R code Kaga signal Wm of the M ² R code Kaga signal Pm However, if the internal buffer is not full due to the M ² R encoded image signal, the 9th part waiting for input of the all-white image signal Wo and the received all-white image signal Wo and the encoding instruction signal Based on M ² R
After encoding, the M ² R encoded image signal V (0) is written in the rest of the internal buffer which is not full, and the next all-white image signal W0 and the encoding instruction signal are awaited for input. Writing to the buffer is performed until the internal buffer is full, and when the internal buffer is full, the reception instruction signal is sent together with the rest of the M ² R encoded image signal Wm and the M ² R encoded image signal V (0) × N. After receiving the tenth part to send to the control part and the EOFB code sending instruction to create the EOFB code,
An FB code is sent to the control section and an eleventh section is provided, and the final scan line is an all-white line and the end of the EOFB code is an M ² R encoded image signal with a byte boundary. An image signal processing device characterized by.