JPH05290203A - Array direction detection method of bar code label - Google Patents

Abstract

PURPOSE:To certainly read a bar code symbol even when the applying position of a bar code label is deviated or inclined. CONSTITUTION:A primary straight line which passes respective optional points S on at least two edges (AB and BC) among for edges showing the border of an image I including the bar code symbol 8 and optionally inclines is continuously set and whether one train of the bar code symbols are read from end to end or not is discriminated from the bar code symbol read by scanning in accordance with the straight line so as to detect a proper scanning direction meeting the applying position of the bar code label.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of reading a multi-stage bar code symbol, and more particularly to a method of detecting a bar code label array direction which automatically detects the bar code symbol array direction. It is a thing.

[0002]

2. Description of the Related Art Bar code labels that are commonly used are
The overall size is standardized to a certain length and width,
Black bars and the like are recorded on the label in a state in which they are arranged in a line with various widths and intervals. In addition, since the amount of information to be recorded is not so large in this one-stage bar code symbol, a multi-stage bar code symbol that has been stacked in several stages has also been developed. Is able to. On the other hand, as bar code readers for reading these bar code symbols, in addition to the handy type that can be used by grasping with one hand, a stationary type that is fixed at a predetermined position has been developed. By the way, in this stationary type bar code reader, the reading light emitted from the reader body is generally projected and scanned in a fixed range and in a fixed direction. In many cases, the sticking position of the bar code symbol is preset to a predetermined position.

[0003]

However, in such a bar code reader, even if the bar code label is stuck at a fixed position, the mounting state of the bar code reader is tilted or the packaging box or the like is deformed. Then, the barcode label may not be read accurately or may not be read. Therefore, in view of the above-mentioned conventional drawbacks, the present invention provides a barcode label array direction detecting method capable of reliably reading barcode symbols even if the barcode label sticking position is displaced or dislocated. It is intended to be provided.

[0004]

That is, according to the present invention, a rectangular or rectangular area including a bar code symbol is imaged, two-dimensional coordinates are set in the imaged image, and a peripheral portion of the image is formed. A linear function y = where the slope a is continuously changed at each point on at least one vertical and horizontal side of the four sides.
ax + b (however, −∞ <a <∞) is sequentially set, the coordinates of each pixel on the straight line indicated by the linear function having the set slope are designated, and while scanning along each of the designated pixels, The bar code symbol on the straight line is read from the image information of, and it is determined from the read information whether the bar code symbol of at least one row has been scanned from the start end to the end, and the arrangement direction of the multi-stage bar code label is detected. To do.

[0005]

According to the present invention, a linear function whose inclination is continuously changed is sequentially set at each point on each of the four sides forming the peripheral edge of the image in at least two vertical and horizontal directions, that is, at each set point. A straight line passing through this point is continuously rotated, and at that time, reading scanning is performed along the straight line of each inclination, and whether or not all the bars can be scanned from the start end to the end of one row of bar code symbols. The array direction of the multi-stage barcode symbol is detected by determining whether or not.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 shows a method of detecting the arrangement direction of a barcode label according to the present invention. This arrangement direction detecting method is composed of first step to seventh step 7. In the first step 1, a rectangular or rectangular area including the barcode symbol 8 (see FIG. 2) is imaged by an appropriate image pickup means, for example, a CCD (charge coupled device) image pickup camera, and a predetermined storage means. To store the image I (see FIG. 2). Second step 2
Then, as shown in FIG. 2, a two-dimensional coordinate O-
Set X and Y. In the third step 3, in the image I captured in the first step 1, at least two vertical / horizontal sides of the four side edges that are in contact with the surroundings and are borders (in this embodiment, the line segment AB in FIG. 2). , A linear function Y = aX + b in which the slope a (-∞ <a <∞) is continuously changed is set at each point S on the line segment BC.
That is, for example, at the point A (0, n) in FIG. 2, in the linear function Y = aX + n (n: Y intercept), the slope a is 0, that is, the slope a is gradually reduced from Y = n. A corresponding straight line is set on the image I. In other words, the straight line passing through the point A is continuously rotated clockwise on the straight line as shown in FIG.

In the fourth step 4, the coordinates (X, Y) of each pixel on the straight line indicated by each linear function having the set constant inclination are designated. In the fifth step 5, the fourth
Each pixel corresponding to the coordinates designated in step 4 is continuously scanned obliquely on the image I, and image information such as black and white corresponding to each pixel on the scanning line is read. In the sixth step 6, it is judged from the image information read in the fifth step 5 whether or not the scanning line is aligned with the array direction of the barcode symbols in one row. That is, whether or not all the codes from the start end to the end of the bar code symbol in one row can be read is determined by the first and last codes such as the read numbers.
It is determined whether or not it matches the preset value. As a result, when it is determined that all the codes of the bar code symbol in one column cannot be read, the process returns to the third step 3 and the process starts again from the third step 3. In the seventh step 7, if it is determined in the sixth step 6 that all the bars of the bar code symbol in one row have been read, from the scanning position that coincides with the straight line indicated by the linear function at that time, that is, in the first row. Scan from the barcode symbol 8A of the eye to the barcode symbol 8Z of the final stage.

[0008]

As described above, according to the method for detecting the arrangement direction of the bar code label according to the present invention, among the four sides forming the boundary peripheral portion of the picked-up image, at least each point on each of the vertical and horizontal sides. By setting a linear function in which the slope is continuously changed in, and rotating the straight line indicated by this function at each of the previous points, and scanning according to each straight line at that time, that is, either In terms of
Further, by performing scanning along a straight line at any inclination, it is possible to detect a scanning position where it can be determined that all the barcode symbols in one row have been read from the start end to the end. Therefore, according to this detection method, the straight line is regarded as a scanning line, and the scanning is performed while moving it in parallel and shifting it up and down, thereby enabling automatic reading of randomly attached multi-stage bar code symbols, A very large effect can be obtained in practical use.

[Brief description of drawings]

FIG. 1 is a flow chart showing a method for detecting the arrangement direction of barcode labels according to the present invention.

FIG. 2 is an explanatory diagram for explaining the method of FIG.

[Explanation of symbols]

 8 barcode symbol I image

Claims (1)

[Claims] 1. An image of a rectangular or rectangular area including a bar code symbol is imaged, two-dimensional coordinates are set in the imaged image, and at least one of the four sides forming the peripheral portion of the image is on each vertical and horizontal side. The linear function y = ax + b (where -∞ <a <∞) in which the slope a is continuously changed is sequentially set at each point of, and the coordinates of each pixel on the straight line indicated by the linear function having the set slope are set. Is specified, the bar code symbols on the straight line are read from the image information there while scanning along each of the specified pixels, and from this read information, at least one row of bar code symbols from the beginning to the end is read. A method for detecting the arrangement direction of a barcode label, which comprises determining whether or not scanning has been performed and detecting the arrangement direction of the multi-stage barcode symbol.