JP5251096B2 - Two-dimensional code / barcode reading device, two-dimensional code / barcode reading method, program, and recording medium - Google Patents

Description

  The present invention relates to a two-dimensional code / barcode reading apparatus, a two-dimensional code / barcode reading method, a two-dimensional code / barcode reading program, and a program recording medium. In particular, two-dimensional code / barcode reading that can be suitably applied to the field of performing various services by reading a two-dimensional code / barcode displayed on the screen of a mobile phone or the like with a flatbed scanner provided in a dedicated terminal. The present invention relates to a two-dimensional code / barcode reading method, a two-dimensional code / barcode reading program, and a program recording medium.

  Reading a two-dimensional code / bar code displayed on a screen of a mobile phone or the like has been conventionally performed. As an example of a method for reading a two-dimensional code / barcode displayed on a screen of a conventional mobile phone, for example, Japanese Patent Application Laid-Open No. 2004-54581 “Information Code Display Method and Information Code Reading Method” of Patent Document 1 and Patent Document No. 2, JP-A 2007-66000, “Portable Information Terminal and Image Processing Method”.

  In the technique disclosed in Patent Document 1, a dedicated image rotation / display application is prepared when a two-dimensional code / barcode is displayed on a liquid crystal screen of a mobile phone. A method has been proposed in which images obtained by rotating and displaying images in 90 degree increments are sequentially scanned, and a two-dimensional code / barcode is read using a total of four images.

In the technique described in Patent Document 2, a method is proposed in which the cell size / bar width of a two-dimensional code / barcode is first detected and image distortion correction is performed based on the detection result. Yes.
Japanese Patent Laying-Open No. 2004-54581 (page 5-7) JP 2007-66000 (page 6-9)

  However, in the conventional techniques as described above, the following problems are not solved.

  The first problem is that in a foldable mobile phone whose hinge can be opened only at a maximum of less than 180 degrees, the screen of the mobile phone and the scanner surface are not parallel, so the image of the two-dimensional code / barcode Is distorted and the two-dimensional code / barcode cannot be read correctly.

  The second problem is that when the image read by the scanner is larger than the screen size of the mobile phone and the background of the mobile phone is also reflected in the image at the same time, the screen of the mobile phone can be detected correctly. It is in the point of disappearing.

  The third problem is that when the scanning method of the flatbed scanner is a method of capturing a two-dimensional image while moving the one-dimensional sensor in the sub-scanning direction, it takes several seconds to complete the scan. If the screen of the mobile phone is switched to the energy saving mode and darkens during scanning, the brightness of the image changes across the 2D code / barcode, and the 2D displayed on the screen of the mobile phone. It is difficult to read codes and barcodes.

  The present invention has been made to solve the above problems, and a two-dimensional code bar capable of stably and accurately reading a two-dimensional code bar code displayed on a screen of a mobile phone or the like. The object of the present invention is to provide a code reading device, a two-dimensional code / barcode reading method, a two-dimensional code / barcode reading program, and a program recording medium.

  In order to solve the above-described problems, a two-dimensional code / barcode reading apparatus, a two-dimensional code / barcode reading method, a two-dimensional code / barcode reading program, and a program recording medium according to the present invention have the following characteristic features. The configuration is adopted.

  (1) In a two-dimensional code / barcode reader that reads a two-dimensional barcode from image data obtained by scanning a screen displaying a two-dimensional barcode / barcode, the two-dimensional barcode is obtained from the scanned image data. After extracting the screen area displaying the barcode, the distortion and inclination of the extracted screen area are corrected, and the two-dimensional code that reads the two-dimensional code barcode from the corrected screen area Bar code reader.

  According to the two-dimensional code / barcode reading apparatus, the two-dimensional code / barcode reading method, the two-dimensional code / barcode reading program and the program recording medium of the present invention, the following effects can be obtained.

  The first effect is to correct the distortion, inclination and density of the image by extracting the screen area of the mobile phone or the like from the scanned image, so that the format of the mobile phone or the like (folding type, straight type), Regardless of the screen size and the environment setting state (energy saving mode), the two-dimensional code / bar code displayed on the screen of a mobile phone or the like can be read accurately. As a result, it is possible to accurately read the two-dimensional code / barcode even in a situation where the model or user of the mobile phone or the like that displays the two-dimensional code / barcode on the screen is unspecified.

  The second effect is that even if the scanning method of the scanner (one-dimensional sensor, two-dimensional sensor) and the installation position of the scanner (reflection of ambient light) are different, the difference is absorbed and displayed on the screen of the mobile phone. Furthermore, it can cope with reading of a two-dimensional code / bar code.

  Preferred embodiments of a two-dimensional code / barcode reader, a two-dimensional code / barcode reading method, a two-dimensional code / barcode reading program, and a program recording medium according to the present invention will be described below with reference to the accompanying drawings. In the following description, a two-dimensional code / barcode reading apparatus and a two-dimensional code / barcode reading method according to the present invention will be described. The two-dimensional code / barcode reading method can be executed by a computer. Needless to say, the program may be implemented as a code / barcode reading program, or the two-dimensional code / barcode reading program may be recorded on a computer-readable recording medium.

(Features of the present invention)
Prior to the description of the embodiments of the present invention, an outline of the features of the present invention will be described first. The present invention relates to a mechanism for reading a two-dimensional code / barcode displayed on a screen of a mobile phone, and first detects a screen area of a mobile phone or the like in scanned image data, and corrects distortion of the screen area. By tilt correction and density correction, the tilt of the screen of the mobile phone and the scanner surface by the hinge angle of the folding mobile phone, the reflection of the ambient light, the energy saving mode of the screen of the mobile phone (brightness change) It is characterized by making it possible to absorb the effects of.

  Thus, in the present invention, when a two-dimensional code / bar code displayed on a screen of a mobile phone or the like is read by a flatbed scanner or the like, a scanning method (one-dimensional scanner, two-dimensional scanner), scanner installation Regardless of the position (ambient light), the type of mobile phone (folding type, straight type), and the state of the mobile phone during scanning, the two-dimensional code / barcode can be read accurately.

(Configuration of the first embodiment)
Next, the configuration of the embodiment of the present invention will be described with reference to FIG. FIG. 1 is a block configuration diagram showing a first embodiment of a block configuration of a two-dimensional code / barcode reading apparatus according to the present invention. A two-dimensional code / barcode reading device 10 shown in FIG. 1 includes at least an input device 1 and a data processing device 2, and can read a two-dimensional code / barcode displayed on the screen of the mobile phone 4. Yes.

  The input device 1 includes at least a scanner device 11 that scans a two-dimensional code / barcode displayed on the screen of the mobile phone 4. The data processing device 2 operates under program control, and includes a straight line detection unit 21, a rectangular shape, and the like. At least an area extraction unit 22, a distortion / rotation correction unit 23, and a two-dimensional code / barcode decoding unit 24 are provided.

  The straight line detection unit 21 detects a straight line from the image data displayed on the screen of the mobile phone 4 given from the scanner device 11 of the input device 1. The rectangular area extraction unit 22 extracts a rectangular area in which the area and the background density are within a predetermined range determined as a mobile screen area from the rectangular area surrounded by the straight line detected by the straight line detection unit 21. The distortion / rotation correction unit 23 performs distortion correction and rotation correction so that the rectangular area (portable screen area) extracted by the rectangular area extraction unit 22 becomes a rectangle with an inclination of 0 degree. In the two-dimensional code / barcode decoding unit 24, the distortion / rotation correction unit 23 detects a two-dimensional code / barcode from the rectangular area corrected to 0 degree of inclination, and performs decoding processing.

(Description of the operation of the first embodiment)
Next, an example of the operation of the two-dimensional code / barcode reader 10 shown in FIG. 1 will be described in detail with reference to the flowchart of FIG. FIG. 2 is a flowchart for explaining an example of the operation of the mobile phone 10 shown in FIG.

  In the flowchart of FIG. 2, first, image data including a two-dimensional code and barcode displayed on the screen of the mobile phone 4 is scanned by the scanner device 11 of the input device 1 and supplied to the straight line detection unit 21 of the data processing device 2. (Step A1). The straight line detection unit 21 detects an edge part existing in the supplied image data, and detects a straight line in the image data based on the detected edge part (step A2).

  Thereafter, the rectangular area extraction unit 22 extracts a rectangular area whose area and background density are within a preset range from the rectangular area surrounded by the straight line detected by the straight line detection unit 21 (step A3). When the rectangular area extraction unit 22 cannot detect the corresponding rectangular area (No in step A4), it determines that the supplied image data is abnormal, outputs an error code indicating that decoding is impossible, and performs processing. finish.

  On the other hand, when the corresponding rectangular area can be detected in the rectangular area extracting unit 22 (Yes in step A4), the distortion / rotation correcting unit 23 determines that the rectangular area extracted by the rectangular area extracting unit 22 has an inclination of 0 degree. The distortion correction and the rotation correction are performed so as to form a rectangular shape (step A5). Thereafter, the two-dimensional code / barcode decoding unit 24 detects the two-dimensional code / barcode from the rectangular area corrected to be a rectangle having a tilt of 0 degrees by the distortion / rotation correction unit 23, and performs the decoding process. Perform (Step A6).

  Next, the operation of the first embodiment will be further described with reference to specific examples shown in FIGS. FIG. 3 is an explanatory diagram showing an example of an operation for detecting a straight line from the two-dimensional code / barcode displayed on the screen of the mobile phone 4, and FIG. 4 extracts a rectangular region from the detected combination of straight lines. FIG. 5 is an explanatory diagram illustrating an example of an operation, and FIG. 5 is an explanatory diagram illustrating an example of an operation of correcting a distortion / inclination of an extracted rectangular area and detecting a two-dimensional code / barcode.

  First, as shown in FIG. 3, edge detection is performed from the image of the mobile phone 4 displaying a two-dimensional code / barcode, and a straight line included in the image is detected (corresponding to steps A1 and A2 in FIG. 2). ). Next, as shown in FIG. 4, a rectangular area whose area and background density are within a preset range as a range corresponding to the screen of the mobile phone 4 is extracted from the detected combination of straight lines (FIG. 2). Equivalent to step A3). Here, when there are a plurality of candidates as the rectangular area, the rectangular area above the image (close to the scan start position) is adopted. Further, as shown in FIG. 5, the distortion correction and the inclination correction are performed so that the rectangular area becomes a rectangle having a rotation angle of 0 degree (corresponding to step A5 in FIG. 2). Finally, a two-dimensional code / barcode is detected from the rectangular area in which the distortion and inclination are corrected as shown in FIG. 5, and the decoding process is performed (corresponding to step A6 in FIG. 2).

(Configuration of the second embodiment)
Next, the configuration of the second embodiment of the present invention will be described with reference to FIG. FIG. 6 is a block diagram showing a second embodiment of the block structure of the two-dimensional code / barcode reader according to the present invention. A two-dimensional code / barcode reading device 10A shown in FIG. 6 includes at least an input device 1 and a data processing device 2A as in the case of FIG. 1, and a two-dimensional code / bar displayed on the mobile phone 4 on the screen. The code can be read.

  The input device 1 includes at least a scanner device 11 that scans a two-dimensional code / barcode displayed on the screen of the mobile phone 4 as in the case of FIG. 1, and the data processing device 2A is the same as in FIG. Although operated by program control, in addition to the case of the data processing device 2 of FIG. 1, it further includes at least an adjacent rectangular area extraction unit 31, a density correction unit 32, and an image composition unit 33.

  The adjacent rectangular area extraction unit 31 inspects whether or not there is an adjacent rectangular area that is in contact with the bottom of the rectangular area extracted as a screen area candidate by the rectangular area extraction unit 22 (near the scan end), and at least the area is within a predetermined range. If there is an adjacent rectangular area, the coordinates are extracted. The density correction unit 32 performs density correction so that the density range of the adjacent rectangular area detected by the adjacent rectangular area extraction unit 31 is the same as the density range of the rectangular area detected by the rectangular area extraction unit 22. In the image composition unit 33, the rectangular image extracted by the rectangular region extraction unit 22 and the adjacent rectangular region corrected by the density correction unit 32 are integrated and set again as a screen region displaying a two-dimensional code / barcode. To do.

(Description of operation of the second embodiment)
Next, an example of the operation of the two-dimensional code / barcode reader 10A shown in FIG. 6 will be described in detail with reference to the flowchart of FIG. FIG. 7 is a flowchart for explaining an example of the operation of the two-dimensional code / barcode reading apparatus 10A shown in FIG.

  In the flowchart of FIG. 7, as in the first embodiment of FIG. 2, first, image data including a two-dimensional code / barcode displayed on the mobile phone 4 is scanned by the scanner device 11 of the input device 1. Is supplied to the straight line detector 21 of the data processing device 2 (step B1). The straight line detection unit 21 detects an edge part existing in the supplied image data, and detects a straight line in the image data based on the detected edge part (step B2).

  Thereafter, in the rectangular area extracting unit 22, as in the case of the first embodiment of FIG. 2, the area and background density of the rectangular area surrounded by the straight line detected by the straight line detecting unit 21 are set in a predetermined range. An inner rectangular area is extracted (step B3). When the rectangular area extraction unit 22 cannot detect the corresponding rectangular area (No in step B4), it determines that the supplied image data is abnormal, outputs an error code indicating that decoding is impossible, and performs processing. finish.

  On the other hand, when the corresponding rectangular area can be detected in the rectangular area extracting unit 22 (Yes in step A4), first, the adjacent rectangular area extracting unit 31 is different from the case of the first embodiment shown in FIG. , The presence or absence of an adjacent rectangular area in contact with the bottom (near the scan end) of the rectangular area extracted as a screen area candidate by the rectangular area extracting unit 22 is checked, and there is an adjacent rectangular area whose area falls within a preset range. If so, the coordinates are extracted (step B5). Here, when the adjacent rectangular area cannot be detected (No in Step B6), the processing in Step B7 and Step B8 is omitted, and the process proceeds to Step B9.

  On the other hand, when the adjacent rectangular area can be detected by the adjacent rectangular area extracting unit 31 (Yes in step B6), the density correction unit 32 displays the density histogram of the rectangular area detected by the rectangular area extracting unit 22. The maximum value and the minimum value are calculated for each of R, G, and B colors. Next, a density histogram of the adjacent rectangular area detected by the adjacent rectangular area extracting unit 31 is obtained, and the maximum value and the minimum value for each color of R, G, B are detected for each of the rectangular areas detected by the rectangular area extracting unit 22. Density conversion is performed so as to be the same as the value (step B7).

  Thereafter, the image composition unit 33 integrates the image of the rectangular region extracted by the rectangular region extraction unit 22 and the image of the adjacent rectangular region whose density is corrected by the density correction unit 32 to generate a two-dimensional code / barcode. A new screen area is set (step B8).

  Next, in the distortion / rotation correction unit 23, the distortion correction and the rotation correction are performed so that the rectangular area integrated by the image composition unit 33 or the rectangular area extracted by the rectangular area extraction unit 22 becomes a rectangle with a slope of 0 degree. (Step B9). Thereafter, the two-dimensional code / barcode decoding unit 24 detects the two-dimensional code / barcode from the rectangular area corrected to be a rectangle having a tilt of 0 degrees by the distortion / rotation correction unit 23, and performs the decoding process. Perform (Step B10).

  Next, the operation of the second embodiment will be further described with reference to specific examples shown in FIGS. FIG. 8 is an explanatory diagram showing an example of an operation for detecting a straight line from a two-dimensional code / barcode displayed on the screen of the mobile phone 4, and FIG. 9 extracts a rectangular region from the detected combination of straight lines. FIG. 10 is an explanatory diagram illustrating an example of the operation. FIG. 10 is an explanatory diagram illustrating an example of an operation for performing density conversion to make the density of the rectangular area and the adjacent rectangular area the same, and integrating the rectangular areas. FIG. 11 is an explanatory diagram illustrating an example of an operation of correcting a distortion / tilt of an integrated rectangular area and detecting a two-dimensional code / barcode.

  First, as shown in FIG. 8, edge detection is performed from the image of the mobile phone 4 displaying a two-dimensional code / barcode, and a straight line included in the image is detected (corresponding to steps B1 and B2 in FIG. 7). ). Here, when scanning the image of the mobile phone 4 displaying the two-dimensional code / barcode, the scanning method of the flatbed scanner captures the two-dimensional image while moving the one-dimensional sensor in the sub-scanning direction. In such a case, since it takes several seconds to complete the scan, when the screen of the mobile phone 4 is switched to the energy saving mode during the scan, the screen becomes dark, and as shown in FIG. The screen of the mobile phone 4 is divided into two areas of light and dark on the image that is to be scanned and captured.

  Next, as shown in FIG. 9, a rectangular area (hereinafter referred to as a rectangular area (hereinafter referred to as a rectangular area) in which the area and the background density are within a range set in advance as a range corresponding to the screen of the mobile phone 4 from the detected combination of lines. (Referred to as step B3 in FIG. 7). Here, when there are a plurality of candidates as the rectangular area, the rectangular area above the image (close to the scan start position) is adopted as the screen area. Thereafter, the presence or absence of an adjacent rectangular area in contact with the bottom of the extracted rectangular area (bright) (near the scanning end) is inspected, and as shown in FIG. 9, the adjacent rectangular area (energy saving mode) whose area is within a preset range If there is a rectangular area darkened by switching to (hereinafter referred to as a rectangular area (dark)), its coordinates are extracted (corresponding to step B5 in FIG. 7).

  Further, as shown in FIG. 10, the density histogram of the rectangular area (dark) is a maximum value / minimum value of each color of R, G, B in the rectangular area (bright). Is converted so that the rectangular area (bright) and the rectangular area after darkness conversion (dark) are integrated (corresponding to steps B7 and B8 in FIG. 7).

  Thereafter, as shown in FIG. 11, distortion correction and inclination correction are performed so that the integrated rectangular area becomes a rectangle with a rotation angle of 0 degrees (corresponding to step B9 in FIG. 7). Finally, a two-dimensional code / barcode is detected from the rectangular area in which the distortion and inclination are corrected as shown in FIG. 11, and the decoding process is performed (corresponding to step B10 in FIG. 7).

(Explanation of effect of embodiment)
The first effect is to correct the distortion, inclination and density of the image by extracting the screen area of the mobile phone 4 from the scanned image, so the format of the mobile phone 4 (folding type, straight type), The two-dimensional code / barcode displayed on the screen of the mobile phone 4 can be accurately read regardless of the screen size and the environment setting state (energy saving mode). As a result, the two-dimensional code / barcode can be accurately read even in a situation where the model or user of the mobile phone 4 displaying the two-dimensional code / barcode on the screen is unspecified.

  The second effect is that even if the scanning method of the scanner (one-dimensional sensor, two-dimensional sensor) and the installation position of the scanner (reflection of ambient light) are different, the difference is absorbed and displayed on the screen of the mobile phone 4. It is possible to cope with reading of the two-dimensional code / bar code.

  In the above description, the two-dimensional code / barcode displayed on the screen of the mobile phone has been described. However, the present invention is not limited to such a mobile phone. For example, the present invention can be applied in the same manner to mobile information terminals (PDA, notebook PC, etc.) having a two-dimensional code / barcode image display function.

  The configuration of the preferred embodiment of the present invention has been described above. However, it should be noted that such examples are merely illustrative of the invention and do not limit the invention in any way. Those skilled in the art will readily understand that various modifications and changes can be made according to a specific application without departing from the gist of the present invention. For example, the embodiment of the present invention can be expressed as the following configuration in addition to the configuration (1) in the means for solving the problems.

(2) When extracting the screen region from the scanned image data, the screen region is extracted by detecting a rectangular region having at least an area within a predetermined range from the image data. 1) Two-dimensional code / barcode reader.
(3) When the rectangular area is detected from the image data, an edge portion existing in the image data is extracted, a plurality of straight lines are detected by the extracted edge portion, and are surrounded by the detected straight lines. The two-dimensional code / barcode reading device according to (2), wherein the rectangular region is detected based on a shape and an area of the region that has been read.
(4) When there are a plurality of the rectangular areas having at least an area within a predetermined range in the image data, the rectangular area closest to the scan start position is set as the screen area. The two-dimensional code / barcode reader of (2) or (3) to be extracted.
(5) When there is an adjacent rectangular area adjacent to the rectangular area extracted as the screen area, the adjacent rectangular area is integrated into the rectangular area, and the combined rectangular area is displayed as a two-dimensional bar. The two-dimensional code / barcode reader according to (4), which is set as the screen area displaying a code / barcode.
(6) The two-dimensional code / barcode reader according to (5), wherein the density of the adjacent rectangular area and the density of the rectangular area are corrected to the same density when the adjacent rectangular areas are integrated into the rectangular area. .
(7) In a two-dimensional code / barcode reading method for reading a two-dimensional barcode from image data obtained by scanning a screen displaying a two-dimensional barcode / barcode, the two-dimensional barcode is obtained from the scanned image data. After extracting the screen area displaying the barcode, the distortion and inclination of the extracted screen area are corrected, and the two-dimensional code that reads the two-dimensional code barcode from the corrected screen area Barcode reading method.
(8) When extracting the screen region from the scanned image data, the screen region is extracted by detecting a rectangular region having at least an area within a predetermined range from the image data. 7) The two-dimensional code / barcode reading method.
(9) When the rectangular area is detected from the image data, an edge portion existing in the image data is extracted, a plurality of straight lines are detected by the extracted edge portion, and are surrounded by the detected straight lines. The two-dimensional code / barcode reading method according to (8), wherein the rectangular area is detected based on a shape and an area of the area being read.
(10) When there are a plurality of the rectangular areas whose area is within a predetermined range in the image data, the rectangular area that is closest to the scan start position is used as the screen area. The two-dimensional code / barcode reading method of (8) or (9) to be extracted.
(11) When there is an adjacent rectangular area adjacent to the rectangular area extracted as the screen area, the adjacent rectangular area is integrated into the rectangular area, and the combined rectangular area is displayed as a two-dimensional bar. The two-dimensional code / barcode reading method according to the above (10), which is set as the screen area displaying a code / barcode.
(12) The two-dimensional code / barcode reading method according to (11), wherein the density of the adjacent rectangular area and the density of the rectangular area are corrected to the same density when the adjacent rectangular areas are integrated into the rectangular area. .
(13) A two-dimensional code / barcode reading program in which the two-dimensional code / barcode reading method according to any one of (7) to (12) is implemented as a program executable by a computer.
(14) A program storage medium in which the two-dimensional code / barcode reading program of (13) is recorded on a computer-readable recording medium.

1 is a block configuration diagram showing a first embodiment of a block configuration of a two-dimensional code / bar code reading device according to the present invention; FIG. 3 is a flowchart for explaining an example of the operation of the two-dimensional code / barcode reading apparatus shown in FIG. 1. It is explanatory drawing which shows an example of the operation | movement which detects a straight line from the two-dimensional code bar code displayed on the mobile phone screen. It is explanatory drawing which shows an example of the operation | movement which extracts a rectangular area from the combination of the detected straight line. It is explanatory drawing which shows an example of the operation | movement which correct | amends distortion and inclination of the extracted rectangular area, and detects a two-dimensional code barcode. It is a block block diagram which shows the 2nd Example of the block configuration of the two-dimensional code barcode reading apparatus by this invention. It is a flowchart for demonstrating an example of operation | movement of the two-dimensional code barcode reading apparatus shown in FIG. It is explanatory drawing which shows an example of the operation | movement which detects a straight line from the two-dimensional code bar code displayed on the mobile phone screen. It is explanatory drawing which shows an example of the operation | movement which extracts a rectangular area from the combination of the detected straight line. It is explanatory drawing which shows an example of the operation | movement which performs density conversion which makes the density of a rectangular area and an adjacent rectangular area the same, and integrates a rectangular area. It is explanatory drawing which shows an example of the operation | movement which correct | amends distortion and inclination of the integrated rectangular area, and detects a two-dimensional code | cord | chord.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input device 2 Data processing device 2A Data processing device 4 Cellular phone 10 Two-dimensional code / bar code reading device 10A Two-dimensional code / bar code reading device 11 Scanner device 21 Straight line detection unit 22 Rectangular area extraction unit 23 Distortion / rotation correction unit 24 Two-dimensional code / barcode decoding unit 31 Adjacent rectangular region extraction unit 32 Density correction unit 33 Image composition unit

Claims (12)

In a two-dimensional code / barcode reader for reading a two-dimensional barcode from image data obtained by scanning a screen displaying a two-dimensional code / barcode,
After extracting the first rectangular area from the scanned image data as a candidate of the screen area displaying the two-dimensional code / barcode by the rectangular area extracting unit ,
The adjacent rectangular area extraction unit extracts a second rectangular area that is in contact with the bottom of the first rectangular area near the scanning end and that has an area size within a preset range;
A density correction unit obtains a density histogram of the first rectangular area, calculates a maximum value and a minimum value for each color of R, G, and B, and obtains a density histogram of the second rectangular area, and calculates R, G, B. After performing density conversion so that the maximum value and the minimum value for each color are the same as the values of the first rectangular area,
The image composition unit integrates the image of the first rectangular area and the image of the second rectangular area whose density has been converted by the density correction unit, and newly sets it as a screen area displaying a two-dimensional code / barcode. And
The distortion-rotation correction unit performs the distortion and inclination of the correction for the integrated area image in the image synthesis unit,
A two- dimensional code / barcode reader for detecting a two-dimensional code / barcode from an image of a corrected area by a two-dimensional code / barcode decoding unit and performing a decoding process . 2. The method according to claim 1, wherein when extracting the first rectangular area from the scanned image data, a rectangular area having at least an area within a predetermined range is detected as the first rectangular area. Dimension code / bar code reader.   When the rectangular area is detected from the image data, an edge portion existing in the image data is extracted, a plurality of straight lines are detected by the extracted edge portion, and are surrounded by the detected straight lines. 3. The two-dimensional code / bar code reading device according to claim 2, wherein the rectangular area is detected based on a shape and an area of the area.   If there are a plurality of rectangular areas in the image data that have at least an area within a predetermined range, the rectangular area that is closest to the scan start position is extracted as the first rectangular area. The two-dimensional code / bar code reader according to claim 2 or 3, wherein   5. The density of the second rectangular area and the density of the first rectangular area are corrected to the same density when the second rectangular area is integrated with the first rectangular area. The two-dimensional code / bar code reader according to any one of the above. In a two-dimensional code / barcode reading method for reading a two-dimensional barcode from image data obtained by scanning a screen displaying a two-dimensional code / barcode,
After extracting the first rectangular area from the scanned image data as a candidate of the screen area displaying the two-dimensional code / barcode,
Extracting a second rectangular area in contact with the bottom of the first rectangular area near the scanning end and having a size within a preset range;
The density histogram of the first rectangular area is obtained and the maximum value and the minimum value are calculated for each of the R, G, and B colors, and the density histogram of the second rectangular area is obtained and the maximum value is obtained for each of the R, G, and B colors. After performing density conversion so that the minimum value is the same as each value of the first rectangular area,
The image of the first rectangular area and the image of the second rectangular area whose density has been converted are integrated, and set again as a screen area displaying a two-dimensional code / barcode,
Performs distortion and inclination correction with respect to the first rectangular region of the image and the density converted the second rectangular region of the image and the image of the integrated region,
A two-dimensional code / barcode reading method in which a two-dimensional code / barcode is detected from an image of a region subjected to distortion and inclination correction, and decoding is performed . 7. The method according to claim 6, wherein when extracting the first rectangular area from the scanned image data, a rectangular area having at least an area within a predetermined range is detected as the first rectangular area. Dimension code / Bar code reading method.   When the rectangular area is detected from the image data, an edge portion existing in the image data is extracted, a plurality of straight lines are detected by the extracted edge portion, and are surrounded by the detected straight lines. 8. The two-dimensional code / barcode reading method according to claim 7, wherein the rectangular area is detected based on a shape and an area of the area.   If there are a plurality of rectangular areas in the image data that have at least an area within a predetermined range, the rectangular area that is closest to the scan start position is extracted as the first rectangular area. The two-dimensional code / barcode reading method according to claim 7 or 8, wherein:   10. The density of the second rectangular area and the density of the first rectangular area are corrected to the same density when integrating the second rectangular area into the first rectangular area. The two-dimensional code / barcode reading method according to any one of the above.   11. A two-dimensional code / barcode reading program, wherein the two-dimensional code / barcode reading method according to claim 6 is implemented as a program executable by a computer.   12. A program storage medium, wherein the two-dimensional code / bar code reading program according to claim 11 is recorded on a computer-readable recording medium.

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