JP2674101B2 - Resolution converter - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resolution converter, and more particularly, it occurs when communicating between a facsimile device having a resolution of inches and a facsimile device having a resolution of millimeters. The present invention relates to a resolution conversion device that corrects a difference in the number of lines of image information.

(Prior Art) As is well known, a G4 type facsimile machine (hereinafter abbreviated as G4 machine) is designed in inches. On the other hand, the G3 type facsimile machine (hereinafter abbreviated as G3 machine) is currently designed for millimeters, but due to the relationship with G4 machines, its input / output device (printer and scanner) will be designed for inches. It is thought to be done. For this reason, it is considered that communication between inch-type and millimeter-type devices will increase in the future.

In addition, the resolution of the input / output device of the G3 machine is as follows,
From the T.5 recommendation, that of the G4 aircraft is considered to be as follows.

G3 machine (millimeter system) G4 machine (inch system) (book / mm) (dot / inch) 8 × 3.85 200 × 100 8 × 7.7 200 × 200 240 × 240 300 × 300 400 × 400 Resolution at 8 × 3.85
(Books / mm) and a resolution of 200 x 100 (dots / inch) for G4 machines are called standard resolutions in line with G3 machines. A resolution of 8 x 7.7 (books / mm) for G3 machines and a resolution of 200 x 200 for G4 machines ( Dot / inch) is called high resolution.

(Problems to be Solved by the Invention) When a manuscript device is transmitted from an inch system device to a millimeter system device or from a millimeter system device to an inch system device, the following resolution (and hence size) mismatch Occurs.

For example, when the document information is transmitted from the inch system device (G4 machine having the G3 function) to the millimeter system device (G3 machine), a size mismatch as shown in FIG. 5 occurs.

(A) When the transmission original is A4 size (210 mm x 297 mm), the size of the reception original shrinks about 3.3 mm in the main scanning direction and decreases in the sub-scanning direction as shown in FIG. About 6.7 mm
It will grow.

(B) When the transmission document is B4 size (257 mm x 364 mm), the size of the reception document is reduced by about 4 mm in the main scanning direction and about 4 mm in the sub-scanning direction, as shown in FIG. It will be extended by 8.2 mm.

On the other hand, when the document information is transmitted from the millimeter system device (G3 machine) to the inch system device (G4 machine having the G3 function), a size mismatch as shown in FIG. 6 occurs.

(C) When the transmission original is A4 size (210 mm x 297 mm), the size of the reception original is about 3.4 mm longer in the main scanning direction and smaller in the sub-scanning direction as shown in FIG. About 6.6 mm
It will shrink.

(D) When the transmission document is B4 size (257 mm x 364 mm), the size of the reception document is about 4.1 mm longer in the main scanning direction and smaller in the sub-scanning direction as shown in FIG. It will shrink about 8 mm.

Therefore, when sending a document from an inch device to a millimeter device, shorten the length in the sub-scanning direction, and conversely, when sending a document from a millimeter device to an inch device, the main scanning direction. If the length is not shortened and is not transmitted, the receiving side will print out the recording paper. In addition, in the case of reception by standard paper, a problem of page division occurs.

Therefore, conventionally, in order to shorten the length, the line information forming the document information is thinned out at equal intervals.

For example, 16 × 16 as shown in FIG.
When the document information consisting of (dots) is reduced in the sub-scanning direction and converted into the image information of 14 × 16 (dots) in FIG. 9B, one line is thinned out every eight lines. As a result, there is a problem that a non-information part which is considered to be not so important as manuscript information and a very important image information part are thinned out without distinction, resulting in deterioration of image quality.

An object of the present invention is to eliminate the problems of the conventional device,
When reducing manuscript information, it is to provide a resolution conversion device with less deterioration in image quality by sequentially thinning out parts that are not considered to be important as manuscript information to obtain a desired reduction ratio.

(Means and Actions for Solving the Problem) In order to achieve the above-mentioned object, the present invention provides a means for obtaining a block B0n in which the number of change points is 0 and continuous for a predetermined number of lines or more from an image of one page, A means for obtaining the ratio of the total number of blocks to the total number of lines and comparing this with a planned ratio, and a means for obtaining a deleted line from the block B0n when the former ratio is larger than the latter ratio. On the contrary, when the ratio of the former is smaller than that of the latter, the block B0n and the number of change points are 1,
Blocks B1n and B2 that are consecutive for the planned number of lines in 2, ...
It is characterized in that it is provided with a means for obtaining the required number of deleted lines from among n, ....

According to the present invention, since the deletion lines are sequentially determined from the lines of the document information having a low degree of importance, it is possible to suppress the deterioration of the image quality to the minimum and perform the thinning-out process, that is, the reduction process.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.
When sending a document from the inch-type device to the millimeter-type device, the number of lines to be thinned to reduce in the sub-scanning direction,
Also, when sending a document from a millimeter device to an inch device, the number of lines to be thinned out for reduction in the main scanning direction is as follows for standard resolution and high resolution, respectively.

First, the principle of the present invention will be described with reference to FIG.

Now, a case will be described in which there is document information (FIG. 2A) similar to that shown in FIG. 7A, and this is reduced by thinning out two lines in the sub-scanning direction. In this case, first, the number of change points of 0 → 1 and 1 → 0 is obtained for each line in the main scanning direction. In the case of this example, the number of change points of each line is as illustrated. Next, continuous block lengths having the same number of change points are obtained. In the case of this example, as shown in the figure, the block lengths where the change points are 0, 2, 4 and 0 are 3, 1, 7 and 5, respectively.

Therefore, in the present invention, the image information area having the smaller number of change points and the larger block length is less important to the manuscript information. Therefore, lines are thinned from the area having the smallest number of change points and the largest number of blocks. To do. In FIG. 2, the first one line is thinned out from the area where the number of change points is 0 and the number of blocks is 5. Next, it is judged whether or not the desired reduction ratio has been achieved. If not, the next one line is thinned out from the area where the number of change points is 0 and the number of blocks is 3. Then, it is again determined whether or not the desired reduction ratio has been achieved.

In this example, since the desired reduction ratio has been achieved, the thinning process ends here. As a result, FIG. 2 (c)
As shown in, the image information can be reduced and converted into image information with little deterioration in image quality.

An embodiment of the present invention will be described in detail below. FIG. 3 is a block diagram showing a hardware configuration of a facsimile machine to which the present invention is applied.

The input unit (scanner) 1 reads a sent document based on an instruction from the control unit 6. The document information read by the input unit 1 has a page memory 3 having a storage capacity of at least one sheet.
Is accumulated in The communication mode instructed from the man-machine interface section 10 is G3 or G4, and inch-
When there is a millimeter conversion instruction, the control unit 6 uses the change point detection unit 12 in the encoding unit 4 to store the change point distribution table 11 of the image in the page memory 3 in the main memory unit 7. Create inside.

Next, the control unit 6 applies an algorithm, which will be described in detail later, to the change point distribution table 11 to determine a deletion target line. When the line to be deleted is determined, the line excluding the line to be deleted from the image image in the page memory 3 is read out to the encoding unit 4, and the encoding unit 4 is read.
Is encoded by the encoding method determined based on the protocol and sent out by the main memory unit 7 or the communication control unit 8. The encoded data sent to the main memory unit 7 is then sent to the communication control unit 8 at an appropriate time according to an instruction from the control unit 6 and sent to the communication line via the NCU 9. In addition, 13 shows an internal bus.

The number of the deleted lines depends on whether the image information is sent in the standard resolution or the high resolution, which is determined by the T.30 protocol performed by the communication control unit 8.

Next, an algorithm for determining the line to be deleted based on the change point distribution table 11 will be described with reference to the flowchart of FIG.

First, a block B0n (n = 1, 2, 3, ...) In which the number of changes is 0 and which continues for M0 lines or more is obtained (step S
1). Here, the M0 line is a predetermined value that is set in advance, and the step S1 means a process of distinguishing among the lines having the number of change points of 0 from the lines which are not to be thinned out.

Next, the ratio of the total number of lines of the block to the total is obtained (step S2). Then, it is judged whether the ratio is n% or more (step S3). The n% is also a predetermined value, and when the step S3 is YES, it means that the ratio of the non-data line at the change point 0 to the total number of lines is large.

When the step S3 becomes yes, a process is performed in which the largest block is selected and one line therein is set as a deletion process line (step S4). Next, it is judged whether or not all the required number of deletion processing lines have been decided (step S5).
For (n = 1, 2, 3, ...) It is determined whether or not a deletion processing line has been determined (step S6). When the determination is no, the next largest block is selected and one line in it is determined as the deletion processing line (step S
7). After that, the determination in step S5 is performed again. If the determination is NO, the determination in step S6 is performed again, while if the determination is YES, the process ends.

When the result of step S6 is YES, the process returns to step S4 and the above process is repeated.

On the other hand, when the step S3 is NO, that is, when the ratio of the non-data line at the change point 0 to the total number of lines is small, the process proceeds to step S8. In step S8, one line in the block B0n (n = 1, 2, 3, ...) Is determined as a deletion processing line. Next, similarly to step S5, it is determined whether or not all the necessary number of deletion processing lines have been determined (step S9).
It is judged whether all the blocks B0n (n = 1, 2, 3 ...) Are processed to determine the deletion processing line (step S10). If No, step S8
Then, the process of steps S8, S9 and S10 is repeated until step S9 or S10 becomes YES.
When the step S9 becomes yes, the series of processing ends,
On the other hand, when step S10 is YES, the next step S
Go to 11.

In step S11, blocks B1n (n = 1, 2, 3, ...) Having a change point of 1 and continuous for M1 lines or more are obtained. Here, the M1 line is also a predetermined value set in advance, and the step S11 is, in the line where the number of change points is 1,
This means a process of distinguishing between lines that are the target of thinning and lines that are not. That is, even when the number of change points is 1, when this line continues for many lines, the importance of the line as data is small, and therefore the process for thinning out the line is performed. The process has the same meaning as in step S1.

Next, a process is performed in which one line in the block B1n (n = 1, 2, 3, ...) Is set as a deletion processing line (step S12), and then, the required number of deletion processing lines are all determined. A determination is made (step S13).
You. When the judgment is No, the block B1n (n = 1,
It is judged whether or not the processing for determining the deletion processing line has been performed for all of 2, 3, ... (Step S1).
Four).

When step S13 becomes yes, a series of processing is ended, while when step S14 becomes yes, the process proceeds to step S15, and the block B2n (n = 1, 2, 3, ...) is performed.

Thereafter, the same processing as described above is sequentially performed until the processing for the block at the maximum change point is reached (step S20).
Yes), this time, processing for extracting the deletion processing lines at equal intervals is performed (step S21).

As described above, according to the present embodiment, the lines to be thinned out are sequentially determined from the block consisting of the lines having a small number of change points, so that it is expected that the thinning process can reduce the deterioration of the image quality. You can Further, even when communication is performed between the inch-type and millimeter-type facsimile apparatuses, there is no fear that one page of document information will be recorded on two standard papers, or that the information will be out of the recording paper and become unreadable. .

In the above embodiment, the configuration and operation in the case of reducing in the sub-scanning direction have been described, but the reduction in the main scanning direction is performed by replacing the number of change points of the line with the number of change points of the line in the sub-scanning direction. It is obvious to those skilled in the art that the same can be realized.

Further, although the above-described embodiment is an example applied to a type in which communication is performed page by page, the present invention is not limited to this, and communication is started after manuscript information is temporarily stored in the main memory. Of course, it can also be applied to the type that does. In this case, the hardware configuration is, for example, the internal bus of FIG.
It can be realized by further adding a page memory, an encoding unit, and a decoding unit to 13.

FIG. 1 is a block diagram showing functions of main parts of the present invention.

In the figure, 21 is from the change point distribution table,
Blocks with 0 change points and more than the planned number of lines
It is a means to search for B0n. 22 is a means for calculating a ratio (m%) of the total number of lines of the block B0n to all lines, and 23 is a first comparing means for comparing the ratio (m%) with a planned n%. .

Further, 24 is a first means for determining a thinning line from the block B0n when m ≧ n, while 25 is m
When <n, it is a second means for sequentially determining thinning lines from the block B0n and the blocks B1n, B2n, ... Obtained by the searching means 26. Reference numeral 27 denotes a second comparing means, which checks whether the number of thinning lines determined by the means 24 or 25 has become equal to the number of thinning lines scheduled to be held at 28. Then, when they become equal, a signal to that effect is sent to the means 24 or 25 to terminate the operation of the means 24 or 25.

As a result, the line to be thinned is determined, and the signal or data relating to the line is output from the means 24 or 25 as needed.

(Effect of the Invention) As described above, according to the present invention, lines in the direction enlarged by resolution conversion can be thinned out in order of decreasing importance of document information or image information, so that deterioration in image quality is small. There is an effect that reduction processing can be performed.

Further, since the lines in the enlarged direction are thinned out by the resolution conversion, there is also an effect that the document information does not stick out from the recording paper on the receiving side and is not recorded, or is recorded over two pages.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an essential part of the present invention, FIG. 2 is a diagram for explaining the principle of one embodiment of the present invention, and FIG. 3 is a block diagram showing a hardware configuration of one embodiment of the present invention. FIG. 4 is a flow chart for explaining the operation of the control unit shown in FIG. 3, and FIG.
FIG. 6 and FIG. 6 are diagrams for explaining enlargement and reduction by resolution conversion, and FIG. 7 is a diagram showing an image reduced by a thinning process by a conventional method. 3 ... Page memory, 4 ... Encoding unit, 5 ... Decoding unit, 6 ...
Control unit, 7 ... Main memory unit

Claims (1)

(57) [Claims] 1. A resolution conversion device for thinning out the number of lines in a direction in which the image information is enlarged when the image information is converted from one resolution to another resolution, wherein the number N of lines to be thinned out (however, , N is a positive integer), a means for obtaining a block B0n consisting of a number of consecutive lines with a change point of 0 and larger than a predetermined number, and a total number of lines of the block B0n A means for comparing the proportion of the number of lines with a predetermined proportion, and the block B0n when the former is larger than the latter.
Means for thinning out the N lines from among
When the former is smaller than the latter, the number of continuous lines is larger than a predetermined number, and the number of change points is 0, 1,
2. A resolution conversion apparatus comprising means for thinning out blocks B0n, B1n, B2n, ...