JP2009060393A - Document camera device, image processing device, image processing method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate an adverse influence in a lighting environment by easier processing, and quickly output images of various documents placed on a document board. <P>SOLUTION: This document camera device has the document board on which a document is placed, photographing parts 21 to 30 which photograph the document board, a memory card 41 which prestores an image of the document board, has a standard luminance distribution, a controller 31 which acquires a differential luminance image between the document board images photographed by the photographing parts 21 to 30 and the document board image stored in the memory card 41 in a standard state, and performs luminance correction for at least document parts in the document board images photographed by the photographing parts 21 to 30 based on the acquired differential luminance image, and a USB interface 37 which outputs an image acquired by the controller 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a document camera device, an image processing device, an image processing method, and a program suitable for a presentation using a data projector device, for example.

  Conventionally, it is possible to magnify and project various documents printed on plain paper in real time by taking an image of a document table on which various documents are placed, converting it to an image signal, and outputting it to a data projector device etc. Camera devices are generally commercialized.

In this type of document camera apparatus, uniform and bright illumination light is not always irradiated to a document depending on the illumination environment in which the document camera apparatus is installed. Therefore, for example, a technique for erasing a hot spot (reflection of a lighting device) on a document using a plurality of images taken at different positions has been considered. (For example, Patent Document 1)
JP 2006-279828 A

  However, the technique described in Patent Document 1 above requires that the document image be photographed multiple times at different positions in order to erase the hot spot, and is placed on the document table for such work. The document image cannot be output immediately.

  The present invention has been made in view of the above circumstances, and its purpose is to eliminate the adverse effects under the lighting environment with simpler processing, and to capture images of various documents placed on the document table. An object of the present invention is to provide a document camera apparatus, an image processing apparatus, an image processing method, and a program that can be output immediately.

  According to the first aspect of the present invention, a document table on which a document is placed, a photographing unit that photographs the document table, a storage unit that previously stores an image of the document table in a state in which a luminance distribution is a reference, and Difference image acquisition means for acquiring a difference image of luminance from the image of the document table obtained by photographing with the image pickup means and the image of the document table in the reference state stored in the storage means, and the luminance obtained by the difference image acquisition means Brightness correction means for correcting the luminance of at least the document portion in the image of the document table obtained by photographing with the photographing means based on the difference image, and output means for outputting the image obtained by the luminance correction means It is characterized by that.

  According to a second aspect of the present invention, in the first aspect of the invention, the difference image acquisition means includes the image of the document table obtained by photographing with the photographing means and the image of the document table in the reference state stored by the storage means. It is characterized in that a luminance difference image is acquired after adjusting the positions of both image patterns.

  According to a third aspect of the present invention, a document camera apparatus that includes a document table on which a document is placed and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing is externally connected. A storage means for storing an image of the document table sent from the externally connected document camera device, the luminance distribution being a reference, and an externally connected document camera A difference image acquisition unit that acquires a difference image of luminance from an image from the apparatus and a document table image stored in the reference state stored in the storage unit, and an external device based on the difference image of luminance obtained by the difference image acquisition unit. A luminance correction unit that performs luminance correction of at least a document portion in an image from a connected document camera device; and an output unit that outputs an image obtained by the luminance correction unit. And butterflies.

  According to a fourth aspect of the present invention, in the invention of the third aspect, the storage unit stores images of the document table in a reference state from a plurality of document camera devices, and performs authentication when the document camera device is externally connected. It further comprises authentication means for performing and image selection means for reading out the image of the document table in the corresponding reference state from the storage means according to the authentication result of the authentication means.

  According to a fifth aspect of the present invention, in the invention according to the fourth aspect, the authentication means stores predetermined image information included in an image from an externally connected document camera device in the storage means. It is performed by comparing with an image of a document stand.

  According to a sixth aspect of the present invention, an image of a document camera device that includes a document table on which a document is placed and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing. A processing method for storing in advance the image of the document table in a state where the luminance distribution is a reference, the image of the document table obtained by photographing with the photographing unit, and the reference stored in the storage step A difference image acquisition step of acquiring a difference image of luminance from the image of the document stand in a state, and an image of the document stand obtained by photographing with the photographing unit based on the difference image of luminance obtained in the difference image acquisition step A luminance correction step for correcting the luminance of at least the document portion, and an output step for outputting the image obtained in the luminance correction step.

  According to a seventh aspect of the present invention, there is provided a document camera device that includes a document table on which a document is placed and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing. An image processing method in an image processing apparatus to be connected, the storage step of storing an image of the document stand in a state where the luminance distribution is a reference sent from the document camera apparatus connected externally, A difference image acquisition step of acquiring a difference image of luminance from an image from an externally connected document camera device and a document table image in the reference state stored in the storage step, and the luminance obtained in the difference image acquisition step A luminance correction step for correcting the luminance of at least the document portion in the image from the externally connected document camera device based on the difference image, and an output process for outputting the image obtained in the luminance correction step Characterized in that had and.

  According to an eighth aspect of the present invention, there is provided a document camera device that includes a document table on which a document is placed, and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing. A program executed by the computer, storing in advance an image of the document table in a state where the luminance distribution is a reference, an image of the document table obtained by photographing with the photographing unit, and the storing step A difference image acquisition step of acquiring a difference image of luminance from the image of the document table in the reference state stored in step B, and a document obtained by photographing with the photographing unit based on the difference image of luminance obtained in the difference image acquisition step A brightness correction step for correcting the brightness of at least the document portion in the image on the table, and an output step for outputting the image obtained in the brightness correction step. Characterized in that to the row.

  According to a ninth aspect of the present invention, there is provided a document camera apparatus that includes a document table on which a document is placed and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing. A program that is executed by a computer built in a connected image processing apparatus and that stores an image of the document table sent from the externally connected document camera apparatus with a luminance distribution as a reference Obtained in the difference image acquisition step, the difference image acquisition step for acquiring a difference image of luminance by the step, the image from the externally connected document camera device and the image of the document table in the reference state stored in the storage step. Brightness correction step for correcting the brightness of at least the document portion in the image from the externally connected document camera device based on the difference image of brightness , Characterized in that to execute an output step of outputting the image obtained by the luminance correction step on the computer.

  According to the present invention, it is possible to reliably eliminate the adverse effects in the lighting environment with simple processing, and to immediately output images of various documents placed on the document table.

(First embodiment)
A first embodiment when the present invention is applied to a document camera apparatus will be described below with reference to the drawings.
FIG. 1 shows an external configuration of a document camera apparatus 10 according to the present embodiment. The document camera apparatus 10 is configured by combining a document table 11, a stand unit 12, and a camera unit 13.

  The document table 11 is composed of, for example, three foldable thin plate members (synthetic resin plates) connected via hinges, and the stand unit 12 stands upright from the end of the central synthetic resin plate. A rotating arm portion 12 a extends on the upper portion of the stand portion 12, and a camera mounting portion 12 b is rotatably disposed at the tip of the rotating arm portion 12 a so as to be parallel to the document table 11.

  The camera unit 13 is attached to the camera attachment unit 12b, and images of various documents placed on the document table 11 are taken.

  A USB connector (not shown) for attaching the USB cable 14 is provided at the lower end on the back side of the stand unit 12. In the document camera device 10, an image of a document sheet photographed by being placed on the document table 11 via the USB cable 14 is photographed by the camera unit 13, and the image signal is externally connected to a device such as a personal computer or data. It is output to a projector device or the like.

Next, a schematic functional configuration of the document camera apparatus 10 will be described with reference to FIG.
FIG. 2 shows a conceptual configuration of an electronic circuit of the entire document camera apparatus 10 according to the embodiment.
In the figure, by driving a motor (M) 21, the positions of some lenses in the photographic lens optical system 22 mounted on the lower surface side of the camera unit 13, specifically, the zoom lens and the focus lens are appropriately moved. . A CCD (Charge Coupled Device) 23, which is a solid-state imaging device, is disposed at an imaging position behind the imaging optical axis of the imaging lens optical system 22 via a mechanical shutter (not shown).

  The CCD 23 is scanned and driven by a timing generator (TG) 24 and a CCD driver (Dv.) 25, and outputs a photoelectric conversion output corresponding to a light image formed at fixed intervals for one screen.

  This photoelectric conversion output is subjected to AGC (automatic gain adjustment) in the sample and hold (S / H) circuit 26 according to the ISO sensitivity set for each primary color component of RGB in the state of an analog value signal. After that, the sample is held and sent to the A / D converter 27.

  The A / D converter 27 converts analog image data into digital data and outputs the digital data to the color process circuit 28.

  The color process circuit 28 performs color process processing including pixel interpolation processing and γ correction processing on digital image data, generates digital value luminance / chrominance image data YUV by matrix conversion, and outputs it to the buffer controller 29. To do.

  The buffer controller 29 once writes the image data YUV output from the color process circuit 28 into the buffer controller 29 once using the composite synchronization signal, the memory write enable signal, and the clock signal from the color process circuit 28. DMA transfer is performed to the DRAM 30 used as a buffer memory.

  The DRAM 30 has an area for holding image data obtained by the above photographing.

  The control unit 31 is configured by a CPU, and is connected via a system bus SB1 to a main memory 32 used as a work memory, a program memory 33 formed of a nonvolatile memory in which operation programs and data are fixedly stored, and the like. Thus, a necessary program or the like is read from the program memory 33, and the control operation of the entire document camera apparatus 10 is controlled while appropriately developing and writing necessary programs and data in the main memory 32.

  Thus, after the DMA transfer of the image data to the DRAM 30 is completed, the control unit 31 reads the image data from the DRAM 30 via the buffer controller 29 and writes it into the VRAM 35 via the display control unit 34.

  The display control unit 34 periodically reads out the image data from the VRAM 35 and outputs it to the display unit 36.

  The display unit 36 is composed of a color liquid crystal panel with a backlight and its drive circuit. The display unit 36 is disposed on the upper surface side of the camera unit 13 and functions as a view finder that allows the user to visually recognize the contents of shooting even when the document camera device 10 is not connected to an external device. By performing display based on the image data, the image captured from the CCD 23 at that time is displayed on the monitor in real time.

  On the other hand, the control unit 31 causes the buffer controller 29 to read out the image data held in the DRAM 30 and outputs it to the USB interface (I / F) 37. The USB interface 37 transmits and receives various types of data including image data between external devices in accordance with the USB 2.0 standard, and outputs image data to the external device by isochronous transfer via the USB cable 14.

  The USB cable 14 also serves as a power cable, and a power line defined by the USB standard is connected to the power controller 38. The power supply control unit 38 generates various voltages, for example, 1.5 [V], 3.3 [V] based on the direct current 5.0 [V] supplied from the USB cable 14, Necessary operating voltage is applied to each circuit.

Further, an auxiliary light driving unit 39, an image processing unit 40, and a memory card 41 are further connected to the system bus SB1.
Under the control of the control unit 31, the auxiliary light driving unit 39 drives the plurality of high-intensity white LEDs 42 to emit light simultaneously, and illuminates the document paper placed on the document table 11.

  The image processing unit 40 performs various types of image processing including luminance correction described later, and stores image data held in the DRAM 30 based on the control of the control unit 31 in accordance with a predetermined standard, for example, JPEG (Joint Photographic Experts Group). Compress data.

  The memory card 41 is detachably attached to the camera unit 13 of the document camera device 10 and records the image data compressed by the image processing unit 40.

  The key input unit 43 includes various key switches provided in the camera unit 13 and the stand unit 12 of the document camera device 10, and a key operation signal from the key input unit 43 is directly sent to the control unit 31. The The control unit 31 executes a control operation according to the key operation signal from the key input unit 43.

  In addition, the program memory 33 is in a state in which nothing is placed by the camera unit 13 in an appropriate lighting environment with no brightness unevenness or the like and sufficiently bright before the document camera device 10 is shipped from the manufacturing factory. Assume that an image obtained by photographing the document table 11 is stored in advance as reference image data.

Next, the operation of the above embodiment will be described.
The following operations are controlled by the control unit 31 reading and executing the operation program stored in the program memory 33.

  FIG. 3 shows an initial operation of the document camera apparatus 10 from the beginning of power-on. When the document camera device 10 is connected to an external device, for example, a data projector device, and the power key of the key input unit 43 is turned on in a state where power is supplied from the external device via the USB cable 14, first, the CCD 23 causes the document table to 11 is photographed by the CCD 23 (step S101). At this time, it is assumed that photographing is performed in a state where no document paper is placed on the document table 11.

  The reference image data stored in the program memory 33 is read in a state in which the captured image data of the current document table 11 obtained in this way is held in the DRAM 30, and the captured image data is converted into reference image data by contour extraction and pattern matching processing. It is assumed that alignment is performed (step S102).

  FIG. 4 illustrates the contents of the reference image data stored in advance in the program memory 33. As described above, this reference image data is not placed by the camera unit 13 in an appropriate lighting environment with no brightness unevenness or the like and sufficiently bright before the document camera apparatus 10 is shipped from the manufacturing factory. The document table 11 is photographed.

  On the other hand, FIG. 5 exemplifies captured image data of the document table 11 in the current state obtained by the processing in step S101. As shown in the drawing, it can be seen that there is a slight shift in the position of the document table 11 occupying the shooting range, and that the upper left side of the image is bright and the lower right side is dark due to the illumination environment.

Thus, by aligning the captured image data with the reference image data, a portion that does not match between the two image data is extracted as shown in FIG.
That is, the thin areas indicated by hatching on the left side and the upper side in FIG. 6 are portions where the two image data do not match, and thereafter, this portion is not considered at all.

  Next, after performing the above alignment, image data representing a luminance difference is obtained by subtracting the captured image data from the reference image data in units of pixels (step S103).

  FIG. 7 exemplifies image data representing the difference in luminance, and shows how bright the reference image is with respect to the captured image. The crease portion on the seat surface of the document table 11 and the cross mark portion in the center are corrected using peripheral luminance information.

  The image data representing the brightness difference thus obtained is temporarily stored in the main memory 32.

  Assuming that preparation for brightness correction is completed as described above, it waits for any document paper to be placed on the document table 11 (step S104). For example, the CCD 23 is driven at a monitor rate of 30 [frames / second] and the image data held in the DRAM 30 is monitored as needed to determine whether or not there is a significant change from the state shown in FIG. Is executed.

  If a document sheet is placed on the document table 11 and the photographed image has a large change, it is determined in step S104, and the document table 11 including the newly placed document sheet is appropriately exposed. Photographing is performed in a state (step S105).

  Then, the obtained image data is corrected using the image data representing the luminance difference acquired in step S103. Specifically, luminance unevenness is corrected by subtracting the luminance difference image data from the captured image data in units of pixels. The corrected image data is output and output from the USB cable 14 via the USB interface 37 (step S106).

  FIG. 8 exemplifies image data on the document table 11 including the document sheet photographed in step S105. In the same figure, as in FIG. 5 above, the luminance distribution is brighter on the upper left side of the image and darker on the lower right side, depending on the illumination environment.

  On the other hand, FIG. 9 exemplifies the content of the image data that is corrected and output by the process of step S106. It can be seen that the luminance distribution due to the illumination environment is corrected so that the entire image has a uniform luminance and is very easy to see.

  Thereafter, it waits for a change in the document paper placed on the document table 11 again (step S107). For example, the CCD 23 is driven at a monitor rate of, for example, 30 [frames / second], and the image data held in the DRAM 30 is monitored as needed to determine whether there has been a significant change from the state shown in FIG. To be executed.

  If it is determined that there is a change in the document paper, the process returns to the process from step S05 again, and the same process is repeated to obtain the image data with corrected luminance and output.

  As described above, according to the present embodiment, the simple processing based on the luminance in the image can surely eliminate the adverse effect under the illumination environment, and the images of various documents placed on the document table can be output immediately. It becomes possible.

  In particular, in the above-described embodiment, the brightness difference image is acquired after adjusting the position of both image patterns based on the image of the document table 11 obtained by photographing and the reference image data stored in advance. did.

  Therefore, the difference in luminance between the two images can be accurately calculated in consideration of the positional deviation that may occur depending on the installation angle of the camera unit 13 between the reference image and the captured image at that time.

(Second Embodiment)
A second embodiment when the present invention is applied to an external device to which a document camera apparatus is connected, for example, a data projector apparatus, will be described below with reference to the drawings.
FIG. 10 shows an external configuration of a presentation system in which the data projector device 50 according to the present embodiment is connected to a plurality of document camera devices 10. In the figure, only one document camera device 10 is shown, but actually, a plurality of document camera devices 10 are connected to the data projector device 50 with respect to the data projector device 50 by USB cables 14, 14. It shall be.

  Note that the external configuration of the document camera device 10 is substantially the same as that of FIG. 1 and the basic circuit configuration of the document camera device 10 is the same as that of FIG. 2, and the same parts are denoted by the same reference numerals. The description of will be omitted.

  FIG. 11 shows a conceptual configuration of the entire electronic circuit of the data projector device 50. In the figure, reference numeral 51 denotes an input / output connector section, which comprises, for example, a pin jack (RCA) type video input terminal, an RGB input terminal, and a USB terminal to which the USB cable 14 is connected.

  Image signals of various standards input from the input / output connector unit 51 are unified into image signals of a predetermined format suitable for projection by the image conversion unit 53 via the input / output interface (I / F) 52 and the system bus SB2. Is sent to the projection drive unit 54.

  At this time, various characters for OSD (On Screen Display) and symbols such as pointers are also sent to the projection drive unit 54 in a state of being superimposed on the image signal as necessary.

  The projection drive unit 54 develops and stores the transmitted image signal in the video RAM 55, and then generates a video signal from the stored contents of the video RAM 55. The projection driver 54 multiplies the frame rate of the video signal, for example, 60 [frames / second] by the number of color component divisions and the number of display gradations, thereby performing a spatial light modulation element ( SOM) is driven for display.

  On the other hand, a light source lamp 58 using, for example, an ultra-high pressure mercury lamp disposed in the reflector 57 emits white light with high luminance. The white light emitted from the light source lamp 58 is colored in primary colors in a time-division manner through the color wheel 59, converted into a luminous flux having a uniform luminance distribution by the integrator 60, and then totally reflected by the mirror 61 to the micromirror element 56. Irradiated.

  Then, an optical image is formed by the reflected light from the micromirror element 56, and the formed optical image is projected and displayed on a screen (not shown) to be projected through the optical lens unit 62.

  The optical lens unit 62 enlarges and projects the light image formed by the micromirror element 56 onto a target such as a screen, and the focus position and the zoom position (projection angle of view) can be arbitrarily changed. .

  That is, both the focus lens and the zoom lens (not shown) in the optical lens unit 62 are controlled by moving back and forth along the optical axis direction, and these lenses are moved by rotating the stepping motor (M) 63. To do.

  A marker sensor 64 is disposed close to the terminal portion of the color wheel 59 so that the marker sensor 64 detects the passage of a marker (not shown) provided on the color wheel 59 and sends a detection signal to the projection drive unit. 54.

  The projection drive unit 54 adjusts the drive timing of the micromirror element 56 based on the detection signal from the marker sensor 64.

  The projection light processing unit 66 performs lighting driving of the light source lamp 58, rotation driving of the motor (M) 65 for the color wheel 59, and rotation driving of the stepping motor 63.

  The CPU 67 performs overall control of all the operations of the above circuits. The CPU 67 executes a control operation in the data projector device 50 by using a program memory 68 that is a non-volatile memory storing an operation program, various fixed data, and the like, and a main memory 69 that is a RAM.

  Further, a key operation signal is directly input from the key switch unit 70 to the CPU 67, and an image storage unit 71 and an audio processing unit 72 are connected via the system bus SB2.

  The key switch unit 70 includes a power key, a mode switching key, a cancel key, a focus key, a zoom key, cursor (“↑”, “↓”, “←”, “→”) keys, an enter key, and the like.

  When the user performs an arbitrary operation using each key of the key switch unit 70, an operation signal corresponding to the key operation is directly input to the CPU 67, and the CPU 67 performs a control operation according to the input from the key switch unit 70. Execute.

  The image storage unit 71 holds various image data for a brightness correction operation and the like described later.

  The sound processing unit 72 includes a sound source circuit such as a PCM sound source, converts the sound data given during the projection operation into analog data, and drives a speaker 73 provided, for example, on the back surface of the main body casing of the data projector device 50 to emit sound. Or, a beep sound or the like is generated if necessary.

Next, the operation of the above embodiment will be described.
All of the operations shown below are controlled by the CPU 67 on the data projector device 50 side reading the operation program stored in the program memory 68, developing it on the main memory 69 and executing it.

  FIG. 12 shows a control operation when the data projector apparatus 50 projects an image from the document camera apparatus 10 newly connected via the USB cable 14.

  At the beginning, by repeatedly determining whether or not a new document camera device 10 is connected, it waits for a new document camera device 10 to be connected (step S201).

  If the document camera apparatus 10 is newly connected, it is determined in step S201, and the document camera apparatus 10 connected in accordance with the USB standard is mutually authenticated (step S202). As a result of this authentication, it is determined whether or not the document camera apparatus 10 has already registered the image data of the reference document table 11 (hereinafter referred to as “reference image data”) in the image storage unit 71 (step S203). ).

  If it is determined that the reference image data corresponding to the image storage unit 71 is not registered, a request signal for transmitting the reference image data to the document camera device 10 via the USB cable 14 is sent. After the transmission (step S204), it waits for the data from the document camera device 10 to be sent in response to the request signal (step S205).

  When the reference image data from the document camera apparatus 10 is received, it is determined in step S205, and the reference image data is newly registered in the image storage unit 71 (step S206).

  If it is determined in step S203 that the corresponding reference image data is already registered in the image storage unit 71, the corresponding reference image data is read from the image storage unit 71 as it is (step S207).

  However, contour extraction is performed using the obtained reference image data and image data (hereinafter referred to as “captured image data”) taken from the document camera device 10 and photographed on the document table 11 at that time. The captured image data is aligned with the reference image data by pattern matching processing (step S208).

  FIG. 4 illustrates the contents of the reference image data registered in the image storage unit 71 in advance or the contents of the newly registered reference image data. This reference image data is obtained from the document table 11 in a state where nothing is placed under a sufficiently bright and appropriate lighting environment without any brightness unevenness before shipping to the manufacturing factory for each document camera device 10. This was taken by the unit 13.

  On the other hand, FIG. 5 exemplifies captured image data transmitted from the document camera apparatus 10 side at that time. As shown in the figure, compared with the image of FIG. 4 described above, the position of the document table 11 occupying within the shooting range is slightly shifted, and due to the lighting environment, the upper left side of the image is bright and the lower right side has a dark luminance distribution. You can see that

Thus, by aligning the captured image data with the reference image data, a portion that does not match between the two image data is extracted as shown in FIG.
That is, the thin areas indicated by hatching on the left side and the upper side in FIG. 6 are portions where the two image data do not match, and thereafter, this portion is not considered at all.

  Next, after performing the above-mentioned alignment, image data representing a luminance difference is acquired by subtracting the captured image data from the reference image data in units of pixels (step S209).

  FIG. 7 exemplifies image data representing the difference in luminance, and shows how bright the reference image is with respect to the captured image. The crease portion on the document table 11 seating surface of the document camera device 10 and the cross mark portion at the center are corrected using peripheral luminance information.

  Image data representing the brightness difference thus obtained is temporarily stored in the main memory 69.

  Assuming that preparation for brightness correction is completed as described above, it waits for any document paper to be placed on the document table 11 of the document camera device 10 (step S210). This is executed by monitoring the captured image data sent from the document camera device 10 as needed to determine whether or not there has been a significant change from the state shown in FIG.

  If a document sheet is placed on the document table 11 of the document camera apparatus 10 and the photographed image has a large change, it is determined in step S210, and the photographed image data sent is sent to the above step S209. Correction using the image data representing the difference in luminance acquired in step 1, more specifically, luminance unevenness correction is performed by subtracting the luminance difference image data from the captured image data for each pixel unit, and the corrected image data is optically corrected. Projection is performed by the lens unit 62 (step S211).

  FIG. 8 exemplifies photographed image data on the document table 11 including the document sheet sent from the document camera device 10. In the same figure, as in FIG. 5 above, the luminance distribution is brighter on the upper left side of the image and darker on the lower right side, depending on the illumination environment.

  On the other hand, FIG. 9 exemplifies the contents of the image data projected after correction by the process of step S211. It can be seen that the luminance distribution due to the illumination environment is corrected so that the entire image has a uniform luminance and is very easy to see.

  Thereafter, while maintaining the above projection state, whether or not another document camera apparatus 10 is newly connected and there is an interruption (step S212), and the photographed image sent from the currently selected document camera apparatus 10 By repeatedly determining whether or not there is a change in the data (step S213), it waits for these states.

  If there is a change in the photographed image data sent from the currently selected document camera device 10, it is determined in step S213, and the new photographed image data is corrected again for luminance correction. The process from step S211 is executed.

  Further, when another document camera apparatus 10 is newly connected and there is an interruption in the process of repeating the processes of steps S212 and S213, it is determined in step S212, and the newly connected document camera apparatus 10 Returning to the processing from step S202 to deal with the above.

  As described above, according to the present embodiment, in a device such as the data projector device 50 that projects captured image data sent from the externally connected document camera device 10, the document is printed by simple processing based on the luminance in the image data. It is possible to surely eliminate the adverse effects of the camera apparatus 10 on the lighting environment, and to immediately process and output images of various documents placed on the document table 11 of the document camera apparatus 10.

  In addition, in this embodiment, each reference image data of a plurality of connected document camera devices 10 is registered in the image storage unit 71, and authentication is performed, and corresponding reference image data corresponding to the result is stored in the image storage unit. Since the data is read from 71, image data subjected to appropriate luminance correction can be output even in an apparatus in which a plurality of document camera apparatuses 10 are connected.

  In the above embodiment, the authentication process has been described as being performed in accordance with the USB standard. However, the present invention is not limited to this, and identification information in an image sent from the document camera device 10, for example, By detecting a specific mark or barcode printed on the upper surface of the document table 11 from the image data, the model or individual of the document camera device 10 may be authenticated, and furthermore, the color of the entire surface of the document table 11 It may be different for each model, and the corresponding model may be specified by detecting the color component of the document table 11 in the image data.

  By using the image information included in the image data sent from the document camera device 10 for the authentication of the document camera device 10 as described above, registration and authentication of the document camera device 10 are not limited to standards such as USB. Can be easily realized by simple image processing software.

  In the second embodiment, the case where the data projector device 50 that projects the image output from the document camera device 10 is used as the external device to which the plurality of document camera devices 10 are connected has been described. The present invention is not limited to this, and the present invention can be similarly applied to a personal computer and other external devices that perform some kind of image processing.

  In addition, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention in the implementation stage. In addition, the functions executed in the above-described embodiments may be implemented in appropriate combination as much as possible. The above-described embodiment includes various stages, and various inventions can be extracted by an appropriate combination according to a plurality of disclosed structural requirements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, if the effect is obtained, a configuration from which the constituent requirements are deleted can be extracted as an invention.

1 is a perspective view showing an external configuration of a document camera apparatus according to a first embodiment of the present invention. 2 is an exemplary block diagram showing a conceptual configuration of an electronic circuit of the entire document camera apparatus according to the embodiment. FIG. The flowchart which shows the processing content at the time of power-on at the time of the embodiment. The figure which illustrates the reference image data of the document stage which concerns on the same embodiment. The figure which illustrates the picked-up image data of the document stage which concerns on the same embodiment. FIG. 3 is a diagram illustrating reference image data of a document table after alignment according to the embodiment. The figure which illustrates the image data showing the difference of the brightness | luminance which concerns on the same embodiment. 3 is a diagram illustrating image data on a document table including document paper according to the embodiment. FIG. 6 is a diagram illustrating image data on a document table including a document sheet after luminance correction according to the embodiment. FIG. The perspective view which shows the connection structure of the document camera apparatus and data projector apparatus which concern on the 2nd Embodiment of this invention. The block diagram which concerns on the same embodiment. The flowchart which concerns on the same embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Document camera apparatus, 11 ... Document stand, 12 ... Stand part, 12a ... Turning arm part, 12b ... Camera mounting part, 13 ... Camera part, 14 ... USB cable, 21 ... Motor (M), 22 ... Shooting lens Optical system, 23 ... CCD, 24 ... Timing generator (TG), 25 ... CCD driver, 26 ... Sample hold (S / H) circuit, 27 ... A / D converter, 28 ... Color process circuit, 29 ... Buffer controller 30 ... DRAM, 31 ... control unit, 32 ... main memory, 33 ... program memory, 34 ... display control unit, 35 ... VRAM, 36 ... display unit, 37 ... USB interface (I / F), 38 ... power supply control unit 39 ... auxiliary light drive unit, 40 ... image processing unit, 41 ... memory card, 42 ... high brightness white LED, 43 ... key input unit, 50 ... data projector device , 51 ... Input / output connector section, 52 ... Input / output interface (I / F), 53 ... Image conversion section, 54 ... Projection drive section, 55 ... Video RAM, 56 ... Micromirror element (SOM), 57 ... Reflector, 58 DESCRIPTION OF SYMBOLS ... Light source lamp, 59 ... Color wheel, 60 ... Integrator, 61 ... Mirror, 62 ... Optical lens unit, 63 ... Stepping motor (M), 64 ... Marker sensor, 65 ... Motor (M), 66 ... Projection light processing part, 67 ... CPU, 68 ... program memory, 69 ... main memory, 70 ... key switch section, 71 ... image storage section, 72 ... audio processing section, 73 ... speaker, SB1, SB2 ... system bus.

Claims (9)

A document table on which documents are placed;
Photographing means for photographing the above-mentioned document table;
Storage means for preliminarily storing the image of the document table in a state where the luminance distribution is a reference;
Difference image acquisition means for acquiring a difference image of brightness from the image of the document table obtained by photographing with the photographing means and the image of the document table in the reference state stored in the storage means;
Brightness correction means for correcting the brightness of at least the document portion in the image of the document table obtained by photographing with the photographing means based on the difference image of brightness obtained by the difference image acquisition means;
A document camera apparatus comprising: output means for outputting an image obtained by the brightness correction means.   The difference image acquisition means acquires the difference image of the brightness after adjusting the position of the image pattern of both the image of the document table obtained by photographing with the photographing means and the image of the document table in the reference state stored in the storage means. The document camera apparatus according to claim 1, wherein the document camera apparatus comprises: An image processing apparatus having a document table on which a document is placed, a photographing unit for photographing the document table, and an externally connected document camera device for obtaining and outputting a document image on the document table obtained by photographing. ,
Storage means for storing an image of the document stand in a state where the luminance distribution is a reference, sent from the document camera device connected externally;
Differential image acquisition means for acquiring a difference image of luminance from an image from an externally connected document camera device and an image of a document table in a reference state stored in the storage means;
Brightness correction means for correcting the brightness of at least a document portion in an image from an externally connected document camera device based on the brightness difference image obtained by the difference image acquisition means;
An image processing apparatus comprising: output means for outputting an image obtained by the brightness correction means. The storage means stores an image of a document table in a reference state from a plurality of document camera devices,
An authentication means for performing authentication upon external connection of the document camera device;
4. The image processing apparatus according to claim 3, further comprising image selection means for reading out the image of the document table in the corresponding reference state from the storage means in accordance with the authentication result of the authentication means.   The authentication means is performed by comparing predetermined image information included in an image from an externally connected document camera device with an image of a document table stored in the storage means. Item 5. The image processing apparatus according to Item 4. An image processing method of a document camera apparatus that includes a document table on which a document is placed, and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing,
A storage step of storing in advance the image of the document table in a state where the luminance distribution is a reference;
A difference image acquisition step of acquiring a difference image of brightness from the image of the document stand obtained by photographing with the photographing unit and the image of the document stand in the reference state stored in the storage step;
A luminance correction step for correcting the luminance of at least the document portion in the image of the document table obtained by photographing with the photographing unit based on the difference image of the luminance obtained in the difference image acquisition step;
An image processing method comprising: an output step of outputting an image obtained in the luminance correction step. An image processing apparatus including a document table on which a document is placed and a photographing unit that photographs the document table, and a document camera device that acquires and outputs an image of the document on the document table obtained by photographing is externally connected. An image processing method comprising:
A storage step of storing an image of the document stand in a state where the luminance distribution is a reference, which is sent from the document camera device connected externally;
A difference image acquisition step of acquiring a difference image of luminance from an image from an externally connected document camera device and a document table image in the reference state stored in the storage step;
A luminance correction step of performing luminance correction of at least a document portion in an image from an externally connected document camera device based on the luminance difference image obtained in the difference image acquisition step;
An image processing method comprising: an output step of outputting an image obtained in the luminance correction step. This is a program executed by a computer built in a document camera device that includes a document table on which a document is placed and a photographing unit that photographs the document table, and obtains and outputs an image of the document on the document table obtained by photographing. And
A storage step of storing in advance an image of the document table in a state where the luminance distribution is a reference;
A difference image acquisition step of acquiring a difference image of luminance from the image of the document table obtained by photographing with the photographing unit and the image of the document table in the reference state stored in the storage step;
A luminance correction step for correcting the luminance of at least the document portion in the image of the document table obtained by photographing with the photographing unit based on the difference image of the luminance obtained in the difference image acquisition step;
A program for causing a computer to execute an output step of outputting an image obtained in the luminance correction step. Built-in image processing device that includes a document table on which a document is placed and a photographing unit that photographs the document table, and a document camera device that obtains and outputs a document image on the document table obtained by photographing is externally connected A program executed by the computer,
A storage step of storing an image of the document stand in a state where the luminance distribution is a reference, sent from the document camera device connected externally;
A difference image acquisition step of acquiring a difference image of luminance from an image from an externally connected document camera device and a document table image in the reference state stored in the storage step;
A luminance correction step for correcting the luminance of at least the document portion in the image from the externally connected document camera device based on the luminance difference image obtained in the difference image acquisition step;
A program for causing a computer to execute an output step of outputting an image obtained in the luminance correction step.

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