JP5486478B2 - Document camera device - Google Patents

Description

  The present invention relates to a document camera device, and more particularly to a document camera device including a display having a transmissive display unit on which a document can be placed.

  When a document such as a slip is read by a document camera in banking business or the like, it is strongly influenced by external light that illuminates the document. That is, because the brightness of the document to be read is usually not uniform due to the influence of the external light, the contrast of a part of the read document data, for example, the part exposed to the external light is different from other parts. become. In such a case, a portion that is easy to read and a portion that is difficult to read are generated in the document data.

  In order to reduce such a difference in readability, a method of processing read data by software, for example, a method of adjusting a threshold value for partial binarization is known.

  Patent Document 1 shows that when it is determined that the illuminance has changed from the reference illuminance environment, the reading accuracy is improved by performing density correction processing using image data copied to the corrected image storage memory. Has been.

JP 2006-157155 A

  As described above, the brightness of a document when reading a document is not uniform due to the influence of external light. For this reason, the contrast of an image obtained by reading a document is not constant, and characters in a dark portion are crushed in black, and characters in a bright portion are skipped and cannot be captured.

  For this reason, in the document camera, it is important to make the contrast of the read image uniform.

  On the other hand, in the conventional technique, the read image is partially subjected to processing by software to perform contrast correction.

  To partially correct the read image, processing for making the image data of the portion easy to read is performed. However, it is necessary to obtain a stable contrast at the time of image capture for data that is desired to be used without processing the read image data, such as seal imprint data.

  The present invention has been made in view of such problems, and provides a document camera apparatus that can obtain stable image data at the time of capturing an image.

  In order to solve the above problems, the present invention employs the following means.

A display with a transmissive display unit on which a document can be placed;
A document camera for photographing a document placed on the display unit;
A memory and a CPU for storing and processing images taken by the document camera;
A detection unit that detects luminance unevenness of the captured image for each part of the image;
A display control unit for adjusting display light of the display unit based on a detection result of the detection unit;
When a portion where brightness unevenness is greater than or equal to a predetermined value and whiteout is detected, the display portion of the display corresponding to the portion emits white light to suppress whiteout.

  In the present invention, as described above, a document is placed on a transmissive display unit, and the document is read after adjusting the contrast by the display unit. Therefore, stable image data can be obtained at the time of capturing an image. it can.

It is a figure explaining schematic structure of a document camera device. It is a figure explaining the detail of the control apparatus which controls a document camera apparatus and a document camera apparatus. It is a figure explaining the processing flow of a control apparatus.

  Hereinafter, embodiments will be described with reference to the accompanying drawings. FIG. 1 is a diagram illustrating a schematic configuration of a document camera device, FIG. 2 is a diagram illustrating details of the document camera device and a control device (PC) that controls the document camera device, and FIG. 3 is a processing flow of the control device. FIG.

  As shown in FIG. 1, the document camera apparatus 1 includes a document camera unit 2 and a transmissive display device such as a liquid crystal display device 3. As shown in FIG. 2, the document camera device 1 is connected to the control device 4, and the control device 4 controls the document camera unit 2 and receives image data captured by the document camera 2.

  The document camera control unit 5 controls the camera unit of the document camera device 1, receives image data captured by the camera unit 2, and stores the received image data in the memory 6.

  The liquid crystal display control unit 8 controls display on the liquid crystal display 3 of the document camera device 1. The screen display control unit 9 controls display of image data and character recognition data displayed on the display device 10 for the operator. The CPU 7 controls each control unit.

  Next, the entire processing flow will be described with reference to FIG. First, the operator receives a slip from the customer, places it on the liquid crystal display 3 of the document camera apparatus 1, and starts a slip reading operation (step 101). The document camera 2 reads the image of the slip, and the document camera control unit 5 of the control device 4 receives the read image data of the slip and stores it in the memory 4. The CPU 7 checks whether or not the luminance of the black portion of the image data is uniform (the luminance is within a predetermined range) (step 102). If the brightness of the black part is uniform (at least within the highly important reading range), it is determined that the read data is optimal, and character recognition from the image data or extraction of the imprinted part from the image data is performed. Etc. are executed (steps 103 and 109).

  If the luminance of the black portion is not within the predetermined range, a region with high luminance (such as a region that is blown out by strong external light) is detected (step 105) and corresponds to the region of the liquid crystal display 3 The liquid crystal display control unit 8 is controlled so that the portion to be emitted emits white light (step 106). As described above, when the back surface of the whiteout portion of the document is irradiated by the liquid crystal display, it is possible to suppress whiteout and make it easy to recognize the characters written on the surface of the document.

  In reading a slip, there is a highly important reading area for each type of business. Even in such a high importance region, as described above, it is checked whether the luminance of the black portion of the image data is within a predetermined range, and if the luminance of the black portion is not within the predetermined range, A region with high luminance (a portion that is difficult to read due to strong external light) is detected (step 107), and the portion of the liquid crystal display 3 corresponding to the region with high luminance is emitted white. The display control unit 8 is controlled (step 108).

  The steps 107 and 108 can be executed following the step 104.

  The adjustment for the luminance of the black portion described above is repeated until the luminance of the black portion falls within a predetermined range. When the luminance of the black portion of the entire screen or the important portion falls within the predetermined range, the slip is read. carry out. In this way, character recognition is performed when the brightness of the black portion of the image becomes optimal.

  There may be a case where the outside light is not sufficiently obtained and the slip placed on the liquid crystal display is dark. In this case, the light emission of the liquid crystal display 3 is strengthened. In this case, the image is not read by the light reflected on the slip surface, but is read by the light transmitted through the slip.

  Even in this case, the light emission intensity and distribution of the liquid crystal display 3 are adjusted, and the image is captured again, and the light emission suitable for recognition is recognized from the result of character recognition of the captured image. Light can be emitted with the intensity and its distribution. That is, an image suitable for image recognition can be displayed on the liquid crystal display. Therefore, it is suitable for storing data that has not been processed by software, such as seal stamp data.

  Further, there are cases where character recognition cannot be performed even if the image is read with the brightness adjusted as described above. For example, when the character to be recognized is a character written so as to cover a peripheral printed portion such as a ruled line, character recognition becomes difficult. In such a case, the light emission color of the liquid crystal display is set to the same color as the ruled lines. This makes it difficult to read the ruled lines and makes it easier to read the written characters.

  The above example has been described on the assumption that the slip to be read is arranged at a predetermined position of the display. However, it is also possible to place the slip at a position where the influence of outside light on the display device is small. In this case, the liquid crystal display 3 in a state in which nothing is displayed and the liquid crystal display 3 in a state in which white is displayed are captured by the document camera unit 2 to acquire an image, and the degree of unevenness existing in the acquired image It is also possible to read the slip by designating the position where the image is read with the image quality of the predetermined or higher and the display state as a position suitable for reading (position where the slip is placed) and the display state.

Since the liquid crystal display 3 is the table on which the slip of the document camera apparatus 1 is placed, the position of the slip can be displayed using the display. In addition, because the position of the voucher differs depending on the work performed by the operator, the size of the voucher and the reading position on the voucher differ, so guidance is displayed for each voucher so that the reading position of the voucher is suitable for reading. It is desirable to do.
As described above, it has been described that a desired contrast is obtained by adjusting the light emission intensity of the liquid crystal display, thereby obtaining optimum data for character recognition. However, when processing an image of a slip as image data, it is possible to easily recognize a necessary part of the image data. That is, the liquid crystal display 3 is caused to emit light in a color that is complementary to the color of the image data that is desired to be easily recognized.

  In this way, by developing the display with a complementary color, it is possible to make the required image data stand out. For example, the seal is red because it is stamped with vermilion. In this case, the background of the seal part is colored green so that the seal can be made conspicuous. When the image data read by the document camera unit 2 is displayed on the display device 10, the image becomes easy to see.

  In the present embodiment, the slip table of the document camera apparatus 1 is constituted by the liquid crystal display 3. For this reason, the liquid crystal display 3 can be displayed in various ways. For example, when the document camera device 1 is installed for bank operator operation, auxiliary information, operation guides and the like for assisting operations can be displayed on the liquid crystal display 3. Thereby, the operator's operation can be assisted without affecting the display of the display device 10 for the operator.

  When the document camera apparatus 1 is installed in a bank consultation corner, it can be used in place of a guidance display for a customer by displaying information for guidance to the customer. In this case, it is possible to reduce the number of installed devices and save space without newly installing a display for the customer.

  It is also suitable for storing colored data such as seals that are not processed by software.

  As described above, the document camera used by the bank is for reading a slip, and the slip is a thin paper medium and does not completely block light.

  The difference in the brightness of the black portion in the image read by the document camera is due to the fact that the outside light does not uniformly strike the slip. For this reason, the brightness of the black portion of the read image can be adjusted by applying light from the back side of the slip. That is, a liquid crystal display can be used on a table on which a slip is placed, and the light emission intensity distribution of the display can be changed so as to cancel the influence of the external light. As described above, when the luminance of the black portion of the read image is not uniform, the non-uniformity of the external light can be compensated by adjusting the amount of light hitting the slip from the back. Thus, after adjusting the light emission intensity of the liquid crystal display, the optimum image can be captured by reading the document again.

  In this way, by reducing the influence of external light, it is possible to stabilize the luminance of the black portion of the image to be read, and to improve the accuracy of character recognition from the read image data by stabilizing the contrast of the image. be able to. In addition, if the character to be recognized is on the ruled line of the slip, if the ruled line is red, it will be difficult to read the ruled line by developing a red color on the liquid crystal display on which the slip is placed. Further, it is possible to improve the character reading accuracy in image recognition. Further, since the read image is not processed by software while improving the accuracy of character recognition, it is suitable for use as seal data.

1 Document Camera Device 2 Document Camera Unit
3 Liquid Crystal Display 4 Control Device 5 Document Camera Control Unit 6 Memory
7 CPU
8 Liquid crystal display control unit 9 Screen display control unit 10 Display device

Claims (4)

A display with a transmissive display unit on which a document can be placed;
A document camera for photographing a document placed on the display unit;
A memory and a CPU for storing and processing images taken by the document camera;
A detection unit that detects luminance unevenness of the captured image for each part of the image;
A display control unit for adjusting display light of the display unit based on a detection result of the detection unit;
A document camera device characterized in that when a portion where brightness unevenness is greater than or equal to a predetermined value is detected as whiteout, a display portion of a display corresponding to the portion emits white light to suppress whiteout. The document camera apparatus according to claim 1 ,
Images with the liquid crystal display not emitting light and with the liquid crystal display emitting white light are respectively acquired by the document camera , and the light emission state and the place where the predetermined contrast is obtained are indicated as the light emission state and the document print. A document camera apparatus, characterized in that a guidance display is provided as a place to place the document. The document camera apparatus according to claim 1 ,
A document camera apparatus, wherein guide information for a customer is displayed on the display unit. The document camera apparatus according to claim 1 ,
A document camera apparatus, wherein the display unit emits light in the same color as a ruled line described in the document.

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