JP3089396B2 - Mark reading apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mark reading apparatus and a mark reading method for reading a mark written on a mark sheet (form) at a high speed.

[0002]

2. Description of the Related Art At present, mark sheets are more important as they are more widely used, from national examinations and census surveys to eventual betting ticket purchases. Therefore, it is very important to read the data written on such a large number of mark sheets at a high speed even a little.

FIG. 5 shows a block diagram of an example of a conventionally used mark reading apparatus.

The mark reading apparatus includes an image input section 21 constituted by an image scanner for reading an image of a mark sheet as image data, and an image input section 21.
Image memory 22 for storing image data captured by
And a line counter 24 for counting up each time one line of image data is stored in the image memory 22.
And a black bit number counter 26 for counting the number of black bits in the bits stored in the image memory 22, and comparing the black bit number counted by the black bit number counter 26 with a threshold value to compare the mark in the mark frame. And a mark determination unit 27 for determining the presence or absence of the mark.

A method of determining a mark according to this example will be described with reference to a form image shown in FIG. First, the image input unit 21
To capture the form image as image data, and store the image data in the image memory 22. At this time, the line counter 24 is counted up every time one line of image data is stored in the image memory 22. It is determined whether or not one line of image data of the mark frame on the mark sheet has been input to the image memory by referring to the line counter value. Here, the line scanned by the image input unit 21 to read one line of the mark frame is in the range of 0 to 10 of the Y coordinate,
When the line counter reaches 10, all the image data has been stored in the image memory 22.

[0006] Next, the position (xf_min [j], xf_max [j], yf_
The number of black bits in a range surrounded by min, yf_max) is counted by the black bit number counter 26, and the mark determination unit 2
If the number of black bits ≧ the threshold value in 7, it is determined that there is a mark, and if the number of black bits <the threshold value, it is determined that there is no mark. When four mark frames are designated as in this case, the number of black bits is counted for each frame and mark determination is performed.

That is, in this mark reading device,
The number of black bits has been counted for all mark frames for which it is necessary to determine whether or not there is a mark.

However, the frame marked by one mark sheet is usually only about 20 to 30% of the whole.
Nevertheless, it is necessary to count the number of black bits for all mark frames for which it is necessary to determine whether or not there is a mark. For this reason, it took a very long time to be able to determine the presence or absence of a mark for all the mark frames.

[0009] By reducing the processing of counting the number of black bits,
As a technique for reducing the time required to determine the presence or absence of a mark, a mark recognition method disclosed in Japanese Patent Application Laid-Open No. 2-96465 has been proposed.

In this mark recognition method, it is determined whether or not there is marked image data in one line read by the image input device, and a valid line or an invalid line is determined. Then, control is performed such that the invalid line is skipped and the presence or absence of the mark is recognized. That is,
When there is no image data indicating a mark in all the mark frames of one line of the mark sheet, the number of black bits is not counted for the mark frame of one line.
It was determined that there was no mark.

However, according to this mark recognition method,
If there is at least one mark frame in one line of the mark frame of the mark sheet, to determine the presence or absence of the mark in each mark frame, the number of black bits must be determined for all the mark frames in that line. Had to be counted. For this reason, when considered in the unit of the mark frame in one line, the processing of counting the number of black bits takes a long time to determine whether or not there is a mark in all the mark frames. It has not been.

[0012]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks of the prior art, and can shorten the processing time for counting the number of black bits and can determine the presence or absence of a mark at high speed. An object of the present invention is to provide a mark reading device and method.

[0013]

In order to achieve the above object, a mark reading apparatus according to the present invention comprises a storage means for sequentially storing image data of a mark sheet captured by an image input means, and an image captured by the storage means. Discriminating means for discriminating to which position the data is image data; and table creation for creating a table indicating the range of the marked image data from the image data stored in the memory means with reference to the discriminating means. Means for determining whether or not there is a mark in each mark frame in the range indicated by the table created by the table creating means.

In this mark reading apparatus, the table is created at the same time when the image of the mark sheet is taken in as image data. On the other hand, it is possible to reduce the number of mark frames for which the presence / absence of a mark needs to be determined based on the created table, so that high-speed mark reading is possible.

The discriminating means includes a first counter for counting each time image data of the image input means in one main scanning direction is stored in the storage means, and a predetermined unit in one main scanning direction. A second counter which counts each time the image data is stored in the storage means, and is cleared when the storage of the image data in one main scanning direction is completed. When there is image data indicating that there is a mark in the image data input during each count between the counts, the coordinates of the image data input during that time in the main scanning direction are registered in a table, and the first It is determined whether there is image data indicating that there is a mark in the image data input between the counts of the counter, and According constant results, it can be assumed that to register the if there is image data showing a mark which range in the sub-scanning direction to the table.

The determining means determines mark frames within a range indicated by the table created by the table creating means, and counts the number of bits of image data having a mark for each of the mark frames. It may be provided with a bit number counting means and a comparing means for comparing this bit number with a threshold value.

Here, the bit number counting means counts the number of bits only within the range in the sub-scanning direction indicated by the table created by the table creating means, thereby limiting the range of counting the number of image bits. Therefore, the presence / absence of a mark can be determined even faster.

According to the mark reading method of the present invention, each time the image data of the mark sheet is input to the storage means by a predetermined number of bits by the image input means, the position of the image data is determined, and the result of the determination is stored in the storage means. A table is created from the stored image data to indicate a range of image data indicating the presence of a mark.

Continuing from the above processing, or after temporarily storing the image data and the table on a magnetic disk or the like and reading it out, only the bits of the image data with marks are marked for each mark frame within the range indicated by the table. The number is counted, and the presence or absence of a mark is determined by comparing the number of bits of image data with a mark with a threshold for each mark frame.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In the following description, a bit means one dot of the image data input from the image input unit 11, and a line is in the X-axis direction in FIG. It means one dot line. A row is a group of a plurality of lines arranged in the Y-axis direction in FIG.
0 line is 1 line. A column refers to a unit that partitions one line at regular intervals.
It is a bit. A black block means a block painted black. In FIG. 3, .largecircle. Indicates a white bit having no fill, and .DELTA. Indicates a black bit having a fill.

FIG. 1 is a block diagram of a mark reading apparatus according to an embodiment of the present invention. In FIG. 1, an image input unit 11 takes in an image of a mark sheet (form) as image data, and is constituted by an image scanner. The image memory 12 stores the image data captured by the image input unit 11. The column counter 13 counts up each time one column of image data is stored in the image memory 12, and is reset every time one line of image data is input.
The line counter 14 counts up each time one line of image data is stored.

The black block position table creator 15 refers to the column counter 13 and the line counter 14 to create a black block position table indicating a range in which black block image data exists from the image data stored in the image memory 12. . The black bit number counter 16 counts the number of black bits in the mark frame near the black block position. The mark determination unit 17 determines whether the black block position table 15
The determination of the mark frame within the range indicated by the table prepared in step (1) and the determination of the presence or absence of a mark in the mark frame are performed by comparing the number of black bits counted by the black bit number counter 16 with a threshold value.

The operation of the mark reading apparatus according to the embodiment of the present invention up to the determination of the presence or absence of a mark will be described.

FIG. 2 is a flowchart showing the flow of processing according to an embodiment of the present invention. FIG. 3 is a diagram illustrating an example of an image of a mark sheet (form). FIG. 4 is a diagram showing a black block position table.

The black block position table creator 15 refers to the column counter 13 and the line counter 14 (S1) to determine whether the column counter has been counted up (S2). If so, the black block position table creator 15 inputs the image data for one column (S3).

Next, it is determined whether or not there is at least one black bit in the column (S4).
Further, it is determined whether a table of the same row has already been created (S5). If not already created,
Create a black block position table for that row (S
6), and register the column coordinates (S7). Here, in the case of the form image in FIG. 3, when the processing has progressed to the third line, a black block position table shown in FIG. 4A is created. On the other hand, if the black block position table for the row has already been created (S5), the column coordinates are registered by overlapping the already created black block position table without creating a new black block position table. (S7).

Next, it is determined whether or not the processing for one line has been completed (S8). If the processing has not been completed, the process returns to step S1, and the same processing is performed for the next column. If completed, it is further determined whether or not there is a black bit in the one line (S9).

If there is at least one black bit in the line, it is checked whether or not there is at least one black bit in the previous line (S10). Otherwise, the Y coordinate of the line is changed to Y. Assuming the black block top coordinates,
Register it in the black block position table (S11). Here, in the case of the form image of FIG. 3, when the processing has progressed to the third line, a black block position table shown in FIG. 4B is created. If there is no black bit in the line, it is checked whether there is no black bit in the previous line (S12). Otherwise, the Y coordinate of the previous line is set to the bottom coordinate of the Y black block. Is registered in the black block position table (S1
3). Here, in the case of the form image of FIG. 3, when the processing has proceeded to the seventh line, the black block position table shown in FIG. 4C is created, and the black block position table for that line is completed. .

The above-described processing is repeated until the image data of all the images on the mark sheet is completely captured (S14). Of course, in the case of the form image of FIG. 3, the above processing is completed with only one line.

Next, using the black block position table created by the above processing, the black bit number counter 16 and the mark determination section 17 determine the presence or absence of a mark in the mark frame as described below (S15). ).

Hereinafter, a method of determining the presence or absence of a mark will be described with reference to the form image of FIG. 3 as an example.

First, within the range of the Y coordinate of each mark frame (yf
_Min, yf_max) by searching the black block position table to see if there is a possibility that there is a black block. Here, the condition that there is a possibility that a black block exists within the range of the Y coordinate of each mark frame is as follows: ｛yf_min ≦ by_m
in [i] ≦ yf_max｝ ∪ ｛yf_min ≦ by_
max [i] ≦ yf_max｝ ∪ ｛by_min [i]
≦ yf_min ≦ by_max [i]｝ ∪ ｛by_mi
n [i] ≦ yf_max ≦ by_max [i]｝ (i =
0 to the number of registered lines−1, and i = 0 in the example of FIG. ∪ indicates a logical sum).

In the example of the form image shown in FIG. 3, when i = 0, yf_min = 1, yf_max = 8, and by_mi
Since n [0] = 3 and by_max [0] = 6, the above condition is satisfied.

Next, when there is a possibility that there is a black block in the range of the Y coordinate of each mark frame, the range of the X coordinate of each mark frame (xf_min [j], xf_max [j])
The black block position table is searched to determine whether there is a possibility that there is a black block in the area (j = 0 to the number of designated mark frames-1).
And j = 0-3). Here, the condition that there is a possibility that there is a black block in the range of the X coordinate of each mark frame is xf
_Min [j] / 32 = bx [i] ｘ xf_max
[J] / 32 = bx [i] (i is a line number having a Y black block). Here, i = 0 and bx [0] =
0.

The first mark frame is when j = 0 and xf_
min [0] / 32 = 16/32 = 0, xf_max
[0] / 32 = 28/32 = 0 and xf_min
[1] / 32 = 28/32 = 0, which satisfies the condition that there is a possibility that a black block exists, so that it is determined that the mark frame is a mark frame that may have a black block.

The second mark frame is when j = 1 and xf_
min [1] / 32 = 28/32 = 0, xf_max
[1] / 32 = 40/32 = 1 and xf_min
Since [1] / 32 = 28/32 = 0, which satisfies the above condition, it is determined that the frame is a possible mark frame.

The third mark frame is when j = 2 and xf_
min [2] / 32 = 40/32 = 1, xf_max
[2] / 32 = 52/32 = 1 and xf_min
[2] / 32 = 40/32 = 1, which does not meet the above condition, so that it is determined at this point that the mark frame has no black block.

The fourth mark frame is when j = 3 and xf_
min [3] / 32 = 52/32 = 1, xf_max
[3] / 32 = 64/32 = 1 and xf_min
[3] / 32 = 52/32 = 1, which does not meet the above condition, so it is determined at this point that the mark frame has no black block.

Next, in the case of a mark frame determined to possibly have a black block by the above processing, the number of black bits is counted within the following range. The range of the black bit count is xf_min [j], xf_max in the X direction.
[J], Y direction by_min [i], by_max
[I] (i = block number with X block).
In the first mark frame, when j = 0, xf_min [0]
= 16, xf_max [0] = 28, by_min
The number of black bits in a range surrounded by [0] = 3, by_max [0] = 6 is counted. Similarly, when j = 1, the number of black bits is counted.

Then, the counted number of black bits is compared with a threshold value to determine the presence or absence of a mark. The mark judgment condition is
If the number of black bits ≧ threshold, there is a mark; if the number of black bits <threshold, there is no mark. Here, if the threshold value is 20, the number of black bits is 25 in the first mark frame, so that it is determined that there is a mark, and the number of black bits is 0 in the second mark frame, so that it is determined that there is no mark.

In the case of the form image shown in FIG. 3, it can be determined that there is no mark without counting the number of black bits of the third and fourth mark frames at all, so that the mark can be read very quickly. it can.

In the mark reading apparatus of the present embodiment, the unit of the column is different from the width of the mark frame, and the second mark frame without any black bit counts the number of black bits. Had occurred. However, if the column unit is adjusted to the interval between each mark frame, it is not necessary to count the number of black bits for a mark frame having no black bits, so that the presence / absence of a mark on a mark sheet can be determined very quickly. Become.

In the mark reading apparatus of this embodiment, two counters, a column counter and a line counter, are used to determine the position of the image data on the mark sheet. However, the means for determining the position is not limited to this.

In the mark reading apparatus of this embodiment, after reading the image data of the mark sheet and creating the black block position table at the same time, the presence or absence of a mark for each mark frame is determined using the black block position table. The determination is performed as a series of operations.
However, only the reading of the image data of the mark sheet and the creation of the black block position table are performed first, and the image data and the black block position table are temporarily stored on, for example, a magnetic disk. It may be determined whether or not there is a mark for.

Although the mark in the above embodiment is black, any mark other than black may be used as long as the presence or absence of image data can be recognized.

[0047]

As described above, according to the mark reading apparatus of the present invention, the time for the process of counting the number of image bits indicating that a mark has been written can be significantly reduced as compared with the conventional example. As a result, the presence / absence of a mark can be determined very quickly.

[Brief description of the drawings]

FIG. 1 is a block diagram of a mark reading device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing a flow of processing according to an embodiment of the present invention.

FIG. 3 is a diagram illustrating an example of a form image.

FIG. 4 is a black block position table.

FIG. 5 is a block diagram of a conventional mark reading apparatus.

[Explanation of symbols]

 11 Image Input Unit 12 Image Memory 13 Column Counter 14 Line Counter 15 Black Block Position Table Creation Unit 16 Black Bit Number Counter 17 Mark Judgment Unit

Claims (6)

(57) [Claims] 1. A storage means for sequentially storing image data of a mark sheet taken by an image input means, a discrimination means for discriminating a position of the image data taken in the storage means, and this discrimination. Table creation means for creating a table indicating a range of image data indicating presence of a mark from the image data stored in the storage means while referring to the means,
A determination unit configured to determine whether there is a mark in each mark frame in a range indicated by the table created by the table creation unit. 2. The image processing device according to claim 1, wherein the determining unit is configured to output one of the image input units.
A first counter that counts each time image data in the main scanning direction is stored in the storage unit, and counts each time image data of a predetermined unit in one main scanning direction is stored in the storage unit, A second counter which is cleared when the storage of the image data in one main scanning direction is completed, and wherein the table creation means includes a mark in the image data input between each count between the counts of the second counter. When there is image data indicating that there is an image data, the coordinates of the image data input during that time in the main scanning direction are registered in a table, and a mark appears in the image data input between the counts of the first counter. It is determined whether or not there is image data indicating that there is, and according to the determination result, in which area in the sub-scanning direction the mark is displayed. Mark reading apparatus according to claim 1, characterized in that to register the if there is data in the table. 3. The method according to claim 1, wherein the determining unit determines a mark frame within a range indicated by the table created by the table creating unit, and a bit that counts the number of bits of image data having a mark for each of the mark frames. 3. The mark reading device according to claim 1, further comprising: a number counting unit; and a comparing unit that compares the number of bits with a threshold value. 4. The apparatus according to claim 2, wherein said bit number counting means comprises:
4. The mark reading apparatus according to claim 3, wherein the number of bits is counted only within the range in the sub-scanning direction indicated by the table created by the table creating means. 5. Whenever the image data of the mark sheet is input to the storage means by a predetermined number of bits by the image input means, the position of the image data is determined, and from the result of the determination, the position of the image data stored in the storage means is determined. A mark reading method, wherein a table indicating a range in which image data with a mark is present is created. 6. The number of bits of image data having a mark is counted only for each mark frame within a range indicated by a table created by the mark reading method according to claim 5, and the number of bits having a mark is determined for each mark frame by a threshold value. A mark reading method characterized in that the presence or absence of a mark is determined in comparison with the above.