JPH02125385A - Image signal processing device - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an image signal processing apparatus for extracting and decoding a barcode area from scanned image data such as in a facsimile.

Conventional technology In the past, many barcodes have been used in logistics and other fields such as supermarkets, and most of them have a scanning pattern in multiple directions, in which at least one scan is made correctly on the barcode label being used. It is configured as follows. (Nikkei Electronics 1980.12.2
2. P142 Types of Barcode Readers) Problems to be Solved by the Invention However, there are no conventional methods and devices for extracting and correctly reading a barcode area from image data scanned in one direction, such as in facsimile scanning. The present invention provides an image signal processing device that can correctly extract a barcode area and accurately decode the barcode.

Means for Solving the Problems In order to achieve the above object, the technical solution of the present invention binarizes an input image signal and stores it in a storage means,
converting the binary data into contour data and expanding the contour data to fill the barcode area;
After contracting the expanded data with an m×m mask to a size that does not erase the filled barcode area, the data is reduced by 1/m data thinning in both the main scanning and sub-scanning directions, and the reduced data is contracted. After the background image is erased by processing and the inclination and center point of the remaining barcode area data are calculated, the data is read out from the storage means in the direction of the inclination angle and the barcode is decoded.

Operation The present invention has the above-mentioned configuration, and after filling the barcode area using the feature that each bar of the barcode is parallel, it performs shrinkage, reduction, and further shrinkage processing.

Delete the background image, leaving the center area of the barcode.

By determining the center and inclination of the barcode from the center area of the remaining barcode and reading data from memory in the direction of the inclination angle of the barcode, decoding is possible even if the barcode label is attached in any direction on the input document. The reason why the expansion process is performed on the outline data of the 0 image is to eliminate the background image having a large area, so that it can be erased by subsequent contraction. Also, both the main scanning and sub-scanning directions are 1
/ m x m contraction is performed before reducing the size of the background image because the white (data = 0) of the background image is thinned out and the black (data = 1) is connected, resulting in a larger area than the barcode area. This is to avoid creating a black area in the background image.

Embodiment FIG. 1 is a block diagram of an image signal processing apparatus in an embodiment of the present invention. In the first factor, 1 is the input terminal of the input image signal (multilevel), 2 is the binarization circuit that binarizes the input image signal of the input terminal l using a partial level threshold, and 3 is the 2
A binary data memory stores the digitized signal, 4 is a contour detection circuit that outputs the contour data of the digitized signal, and 5 is an expansion processing circuit that scans the contour data and calculates the logical sum of the data within the scanning window and outputs it. Contour signal expansion circuit that fills in between the contour data of the barcode, 6 is m×m that scans the expansion data
An m×m contraction circuit performs a contraction process that takes the logical product of the data within the scanning window and outputs it. 7 is a reduction circuit that performs a contraction process that takes the logical product of the data within the scanning window and outputs it. 7 is a reduction circuit that performs reduction processing by inputting 1/m thinning of the m×m contraction data in both main and sub-scanning, and a scan that scans the reduced data. A reduction/shrinkage circuit that performs a logical product of the data within the window and outputs it, leaving a part of the barcode area and erasing the background image area. 8 is a slope/shrinkage circuit that calculates the slope and center of the barcode area from the shrunken data. central arithmetic circuit,
Reference numeral 9 represents an address calculation circuit that reads data from the binary data memory 3 according to the tilt direction, and reference numeral 10 represents a barcode decoding circuit that decodes a barcode from the data read from the memory.

The operation of the above configuration will be explained below. An input image signal (multi-value) at an input terminal 1 is converted into a binary code by a binarization circuit 2, and then stored in a binary data memory 3. On the other hand, a contour detection circuit 4 converts the binary code into a contour signal, and a contour signal expansion circuit 5 expands the contour signal to fill the barcode area. An m×m contraction circuit 6 contracts the expanded signal using an m×m scanning window, and a reduction/contraction circuit 7 compresses the signal contracted by the m×m scanning window by 1/m in both the main scanning and sub-scanning directions. By performing reduction and contraction to a predetermined size, the background image is removed while leaving the barcode area. The expansion is performed by the width of the thick barcode, and the reduction rate and the amount of contraction after reduction are large to the extent that the short sides of the barcode area remain, increasing the background image removal effect. 8, the inclination and center of the barcode are determined, and the address arithmetic circuit 9 stores data in the data memory 3 along the inclination angle.
Calculate the address to read the barcode data from.

The data read out from the data memory 3 at the read address is decoded by a barcode decoding circuit 10 to determine the barcode.

Each of the above configurations will be explained in more detail below. The binarization circuit 2 simply converts the input image signal into two at a certain threshold level.
This is a general circuit that converts into values. The contour detection circuit 4 scans the binary image data with a 2.times.2 scanning window and outputs contour signal data by calculating the following formula.

FIG. 2 shows a scanning window for detecting the contour.

1) is binary image data, 12 is a 2×2 scanning window,
A contour signal output R is calculated from each data A, B, C, and D of the scanning window using the following equation.

R=(A0B10+D) (A-B-C-D) The contour signal expansion circuit 6 is a circuit that takes the logical sum of all the data within the scanning window and outputs the result as an output signal. If the size of the scanning window is a circular mask with a diameter r+1, where r is the width of a wide black or white bar, the barcode area can be filled. FIG. 3 shows an example of a circular mask with a diameter of 8. The m×m contraction circuit 6 is a circuit that performs the logical product of all the data within the m×m scanning window and generates an output signal. The reduction/contraction circuit 7 reduces the input data by decimating the input data by 1/m in both main scanning and sub-scanning, and calculates the logical product of all the data within the scanning window that scans the reduced data to generate a contracted output signal. This is the circuit. When the short side of the barcode area filled in by the expansion process is S, and the reduction ratios in the main scanning direction and the sub-scanning direction are each k, the amount of contraction of the contraction circuit is set to the maximum value within a range smaller than -8. Then, much of the background noise can be removed while leaving the barcode area. The purpose of this reduction is to reduce the scanning window size for contraction and simplify the circuit configuration, and to reduce the amount of data for slope/center calculations to shorten calculation time. However, since the error in the center coordinates also increases, the reduction ratio must be determined in consideration of the required accuracy. The slope/center calculation circuit 8 calculates the slope and center of the barcode from the black (data=1) data address of the output signal of the reduction/contraction circuit 7.

An example of calculating the slope and center point when image data as shown in FIG. 4 is an input signal to the slope/center calculation circuit 8 will now be described. Figure 13 shows the image data area (corresponding to the data memory area at a size multiplied by the reduction ratio).
14 is a barcode area, 15 is a barcode area contracted by the reduction/contraction circuit 7, and is an input image to the tilt/center calculation circuit 8.

It is assumed that there is no other background noise, that the barcode is rectangular, and that it can be decoded by reading it in the direction of the long side. The four points of the rectangle are (x 1 + 'I + )% (x2. yz),
(x5 y3) and (X413'4), respectively (xlm yt); the point pymin(
x2. yz); Point P where V is maximum)'ma
x(x3. y5); point pxmln where x is minimum
(X41)'a) ; Point pxma where x is maximum
In the operation below x, l ym −yn l > l
When xm-Xn is 1, the calculation is performed by exchanging the X and y coordinates.

In the example in Figure 4, the slope a is from the two long sides as a = (yz - y3) / (X2 - x5)
i fcha = (ya −y,) / (
X4- xl) If the slope is reversed, a = (12-ya) / (X2- x4)
or a = (ys - yt) / (xs
-xl) The center (xo*yo) is '/a = (X4-
Each coordinate point of pxmin + pxman (x1 + yt
) (xzt yz) CX5I y3) (xa +
y4) is shown. (A) is the starting point,
(B) shows the black signal detecting section detecting the first black signal from the input image signal--scanning line data.

If there is no black signal, it is determined whether the sub-scanning has ended in (C), and if it has ended, the process goes to the abnormal end (D) in which the black signal cannot be detected, and if the sub-scanning has not ended, it goes to the black signal detection section in (B). return. (B
) When a black signal is detected in (E), the process goes to each pointer initial value setting section.Pymin* pymax+ Pxmin+
px□Set the first address where the X and y point signals of each point were detected. Next, in (F), it is determined whether the sub-scanning is finished, and if it is finished, it goes to abnormal termination in (p), and if it is not finished (
To the black signal detection section in G), the black signal detection section in row <o (G) detects a black signal from the input image signal of the next line - the data of the scanning line. When a black signal is detected, each pointer in (H) is updated.〈0Here, the starting point of the detected black signal is
s, the end point is p. 1) Set the address of s to the x+y coordinates of point pymax when closing, and if the address of point p3 is smaller than the X address of point Pxmin, set the address of point pxmin.
Set the address of point p to the X, y coordinates of , and if the X address of point p0 is larger than the X address of point P Return to sub-scanning end determination. When the black signal detecting section (G) no longer detects the black signal, the process goes to (I) and ends normally.

The address calculation circuit 9 calculates an address for reading data in accordance with the slope of the bar code after data input to the binary data memory 3 is completed. A straight line y = a x passing through the center is determined from the slope a determined by the slope/center calculation circuit 8 and the center (xo, yo), and data is read out along the straight line. Read address x+y
x = 1.2.3... y = ax + b b = ()'o - axo) / k The slope/center calculation circuit 8 and the address calculation circuit 9 are configured by a microcomputer. , <- The code decoding circuit 10 can apply the conventional barcode decoding technique as is, and decodes the barcode by, for example, comparing it with a code reference table.

shows part of a picture with a barcode label pasted on a single character background image. FIG. 6 (bl is a contour image of the same figure (at), and FIG. 6 (cl is a selected expanded image of the same figure (bl).

Figure 6 (dl is an image obtained by logical product reduction of the image in cl (enlarged display), Figure 6 (el is an image obtained by contracting the image in di (displayed) in the same figure), Figure 6 (f ) shows how the solid line 25 on the barcode is obtained as a result of calculating the barcode reading position on the binary data memory from the image el.

In the above embodiment, the processing was carried out for a label having a rectangular barcode area in which the total digit length of the bar is longer than the height of the bar, but the processing may be carried out as follows for labels having other shapes.

FIG. 7 shows three types of barcodes with different shapes. FIG. 7 (Al is the barcode shape explained in the examples so far, and is a label in which the total length of the bar is longer than the height of the bar. Therefore, the longitudinal direction AA of the barcode area 26 is ' is read, the barcode can be decoded. On the other hand, Figure 7 (bl) is the opposite case, and is a label where the height of the bar is longer than the total digit length of the bar. In this case, the barcode area 23 Barcode decoding is performed by reading BB' perpendicular to the longitudinal direction AA' of the contracted area 29.
a).

(In the case where the barcode area 30 is almost square in the middle of bl, in this case, the contracted area 3)
By decoding both A' and BB', it is possible to obtain the correct decoding result for one of them.

If it is not known in advance whether it is the type shown in FIG. 7(a) or the type shown in FIG. 7(bl), it is advisable to always read both AA' and BB' to decode the barcode.

Effects of the Invention As described above, the effect of the present invention is that the inclination direction of the barcode can be detected and the unidirectional scanning image data stored in the storage means can be read out and decoded in the inclination direction. This has great effects, such as being able to decode the barcode label even if it is pasted in any position or direction on the input document.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an image signal processing device according to an embodiment of the present invention, FIG. 2 is a conceptual diagram of a scanning window for contour detection, which is the main part of the device, and FIG. A conceptual diagram of an example of a circular mask, Fig. 4 is a conceptual diagram of an image example of the contracted barcode area, Fig. 5 is an operation flow diagram for calculating addresses of four rectangular areas of the same contracted barcode, and Fig. 6 (al~(fl is a diagram showing the processing state of an image containing the same barcode, FIGS. 7(a) to (cl) are conceptual diagrams of barcodes with different shapes. 4... Contour detection circuit, 5 ...contour signal expansion circuit, 6
...m×m contraction circuit, 7...reduction/contraction circuit, 8.
...Inclination/center calculation circuit, 9...Address calculation circuit. Name of agent: Patent attorney Shigetaka Awano and 1 other person

Claims (4)

[Claims] (1) Binarization means for converting scan-resolved data of an original image including a rectangular barcode area into binary data, storage means for storing the binary data, and contour outputting contour data of the binary data. a detection means, a contour signal expansion means for expanding the contour data by a predetermined size by a logical sum of data within a scanning window for scanning the contour data, and filling in areas between the contour data of the barcode; and m× for scanning the expanded data. an m×m shrinking means that outputs a logical product of m-sized data within a scanning window; and a scanning window that reduces the m×m shrinking data by inputting a thinning of 1/m in both main scanning and sub-scanning and scans the reduced data. a reduction/contraction means for erasing a background image area while leaving a part of the barcode area by shrinking the reduced data by a predetermined size using a logical product of data within the area; and a slope of the rectangular barcode based on the reduced/contracted data. an inclination/center calculation means for calculating a center and an address calculation means for calculating an address for reading data from the storage means according to the direction of the slope; and a barcode for decoding a barcode from the data read from the storage means. An image signal processing device comprising decoding means. (2) For the image signal processing device according to claim (1),
An image signal processing device that includes barcode reading direction determining means for determining the digit direction of a barcode on a barcode label. (3) The image signal processing apparatus according to claim 2, wherein the barcode reading direction determining means manually instructs the direction in advance. (4) Barcode reading direction determining means are always orthogonal 2
3. The image signal processing apparatus according to claim 2, wherein the image signal processing apparatus performs correct barcode decoding based on reading direction and decoding determination.