JP4232682B2 - Electronic camera and program - Google Patents

Description

  The present invention relates to an electronic camera and a program for photographing and recording document information.

Conventionally, as an electronic camera that captures and records document information such as characters, figures, images, etc., for example, it has a camera body attached via an arm to a platform on which the subject is placed, and the subject and the camera body are moved There is known a document camera in which the photographing position of a subject is moved (see Patent Document 1). In addition, in order to correct the distortion of the image obtained by photographing the character information written on business cards, postcards, catalogs, billboards, bulletin boards, etc. with a digital camera, a rectangular image that is the target of distortion correction is extracted, There is known a distortion correction method and apparatus that corrects this to a rectangle without distortion (see Patent Document 2).
JP-A-10-229515 JP 2003-58877 A

  However, the document camera disclosed in Patent Document 1 also requires a slide member that moves the shooting position of the subject, which makes the entire apparatus large. Further, in the distortion correction method and apparatus disclosed in Patent Document 2, a quadrilateral image extracted from a captured image after camera shooting is corrected to a rectangular shape without distortion. However, image correction after shooting is premised. Therefore, for example, in the case where the original rectangular image is not photographed in an optimal state, that is, in the case of an image that is too small or an image that is partially missing, even if distortion correction is performed, preferable characters I can't get information. For example, when a business card is shot with a camera, if the shooting status of the business card is poor, the characters on the business card become unclear or the entire outline of the card cannot be extracted as a rectangle. For example, the zoom operation is performed while finely adjusting the direction in which the camera is directed, which necessitates careful shooting and places a heavy burden on the photographer.

The subject of the first invention is that it can be used as a normal camera or a document camera for photographing document information, and when used as a document camera, the document information can be printed without carefully adjusting the photographing state of the document information. It is to be able to photograph information in an optimal state at all times and to photograph while confirming the user's intention.
According to a second aspect of the present invention, when an area including document information is identified as a document area by analyzing a monitor image, the document can be printed without performing a special operation even if the document area cannot be identified from the original monitor image. An area can be automatically specified, and document information can always be photographed in an optimum state without carefully adjusting the photographing state of the identified document information.

The invention according to claim 1 (first invention) is an electronic camera having a document photographing mode for photographing document information and a standard photographing mode for photographing an arbitrary subject. In the document photographing mode, a monitor image is captured. By specifying, a specifying means for specifying an area including the document information in the monitor image as a document area by analyzing, an identification display means for identifying and displaying the document area specified by the specifying means on the monitor screen, and the identification display means When the document area is identified and displayed, when the document area is instructed to be photographed, the optical system is driven and controlled so that the document area is in a predetermined state with respect to the monitor image area. And a control means for changing the imaging conditions.
Furthermore, a program for realizing the main functions shown in the invention described in claim 1 is provided to the computer (the invention described in claim 13).

The invention described in claim 1 may be as follows.
When there are a plurality of document areas, the specifying unit specifies a document area having the maximum size among the plurality of document areas (the invention according to claim 2).

  When there are a plurality of document areas, the specifying unit specifies a document area located in a central portion of the monitor screen among the plurality of document areas (the invention according to claim 3).

  When the identified document area is identified and displayed on the monitor screen, the identification display means identifies and displays the outline portion of the area (the invention according to claim 4).

  The specifying unit specifies a document area based on whether or not an image portion having a predetermined shape is included in the monitor image by analyzing the monitor image.

  The specifying means specifies a document area based on whether or not a character string is included in the monitor image by analyzing the monitor image (the invention according to claim 7).

  The control means drives and controls the optical system so that the photographing direction is located in the central portion of the monitor image area when the document area is located at a biased position in the monitor image area. Change (Invention of Claim 8).

  When the document area is smaller than the maximum size of the monitor image area, the control means drives and controls the optical system so that the document area is within the monitor image area and is equal to the area size. The photographing magnification is changed (the invention according to claim 9).

After changing the shooting condition of the document information by driving and controlling the optical system so that the document area is in a predetermined state with respect to the monitor image area, the document area in the document area shot under the changed shooting condition Correction processing means for processing the image is provided (the invention according to claim 10).
Here, in a state where the image in the document area processed by the correction processing means is displayed on the monitor screen, the image is recorded and stored in the recording medium according to the recording instruction of the image, and according to the cancellation instruction of the image If the document area is released as a non-photographing object (the invention according to claim 11), the user's intention can be taken into consideration.

The invention according to claim 5 (second invention) is an electronic camera for photographing document information, wherein the monitor image is analyzed to specify a region including the document information in the monitor image as a document region. And a control means for changing the photographing condition of the document information by driving the optical system, and when the document area cannot be specified by the specifying means, the optical system is driven and controlled by the control means. Repeat the operation to re-specify whether or not the document area is included in the monitor screen while changing the shooting condition of the document information, and if the document area can be identified as a result, the The imaging condition of the document information is changed by driving and controlling the optical system so that the document region is in a predetermined state with respect to the monitor image region.
Further, a program for realizing the main functions shown in the invention described in claim 5 is provided to the computer (the invention described in claim 14).

The invention described in claim 5 may be as follows.
If the document area cannot be specified even after repeating the re-specification operation, the optical system is driven and controlled to return to the standard photographing condition.
Further, the invention according to claim 5 may be the invention according to claims 6 to 11 described above.

  According to the invention described in claim 1 (first invention), the document photographing mode and the standard photographing mode are provided, and in the document photographing mode, the monitor image is analyzed to analyze the monitor image and include the document information in the monitor image. Is specified as a document area, and when this document area is instructed as an object to be photographed in a state where the document area is identified and displayed on the monitor screen, the document area is set to a predetermined area with respect to the monitor image area. Since the optical system is driven and controlled so that it is in a state, the shooting conditions for document information are changed, so it can be used as a normal camera or a document camera for shooting document information, and when used as a document camera Even without carefully adjusting the shooting state of the document information, you can always shoot the document information in the optimal state and check the user's intention. Significantly reduce the burden on the photographer, further, when performing various corrections on the image captured at the optimum condition, it is possible to perform the correction accurately.

  According to the invention described in claim 2, in addition to the same effect as that of the invention described in claim 1 described above, when there are a plurality of document areas, the maximum size document area is selected from the plurality of document areas. Since the document area is specified, the document area having a high probability can be automatically specified when the document area is specified from the monitor image.

  According to the invention described in claim 3, in addition to the same effect as that of the invention described in claim 1 described above, when there are a plurality of document areas, the central part of the monitor screen is the plurality of document areas. Since the document area located is specified, the document area having a high probability can be automatically specified as in the second aspect of the invention.

  According to the invention described in claim 4, in addition to having the same effect as that of the invention described in claim 1, when the specified document area is identified and displayed on the monitor screen, the outline portion of the area is identified and displayed. Thus, the automatically specified document area can be easily confirmed.

  According to the sixth aspect of the invention, in addition to having the same effect as the first aspect of the invention described above, whether or not an image portion of a predetermined shape is included in the monitor image by analyzing the monitor image. Based on the specified shape (for example, a rectangle) from the monitor image obtained by capturing standard paper such as business cards and postcards, whiteboards, bulletin boards, etc. The photographing part of the whiteboard can be easily specified as the document area.

  According to the invention described in claim 7, in addition to having the same effect as that of the invention described in claim 1, the document image is printed based on whether or not a character string is included in the monitor image by analyzing the monitor image. Since the area is specified, even if the postcard, whiteboard, bulletin board, etc. where character information is not filled in are accidentally or mistakenly photographed, it can be treated as being excluded from the drawing area. The area can be identified more reliably.

  According to the invention described in claim 8, in addition to the same effect as that of the invention described in claim 1, the document area is monitored when the document area exists at a biased position in the monitor image area. Since the photographing direction is changed by driving and controlling the optical system so as to be located at the center of the image area, it is possible to always photograph the document area at an appropriate position.

  According to the ninth aspect of the present invention, in addition to the same effect as the first aspect of the present invention, when the document area is smaller than the maximum size of the monitor image area, the document area is within the monitor image area. Since the optical magnification is changed by driving the optical system so that it is within the same area size as that of the area, photographing at the maximum magnification is always possible.

According to the invention described in claim 10, in addition to the same effect as the invention described in claim 1, the optical system is driven and controlled so that the document area is in a predetermined state with respect to the monitor image area. Since the image in the document area shot under the changed shooting condition is processed and corrected after changing the shooting condition of the document information, it is possible to obtain a high-quality image in which distortion and the like are corrected.
Here, in a state where the image in the document area after the correction is displayed on the monitor screen, the image is recorded and saved on a recording medium according to the recording instruction of the image, and the document area is stored according to the cancellation instruction of the image. You may make it cancel | release as imaging | photography object (Invention of Claim 11).

  According to the invention described in claim 5 (second invention), when the area including the document information in the monitor image is specified as the document area by analyzing the monitor image, the document area cannot be specified. In such a case, the optical system is driven and controlled, and the operation for re-specifying whether or not the document area is included in the monitor screen is repeated while changing the photographing condition of the document information. As a result, the document area is identified. If it is possible to change the shooting condition of the document information by driving the optical system so that the specified document region is in a predetermined state with respect to the monitor image region, Even if it is impossible to specify the document area on the monitor image, the document area can be automatically specified without performing any special operation, and the document information can be obtained without carefully adjusting the shooting state of the specified document information. Always It is possible to shoot in an appropriate state, greatly reducing the burden on the photographer, and further, when performing various corrections on an image shot in the optimal state, it becomes possible to perform the correction accurately. .

According to the twelfth aspect of the present invention, in addition to the same effect as that of the fifth aspect of the invention described above, the optical system can be used when the document area cannot be specified even after repeating the respecifying operation. Since the drive control is performed to restore the standard shooting conditions, the shooting of document information can be automatically canceled.
In addition, the second invention has the same effects as those of the inventions described in claims 6 to 11 described above.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
FIG. 1 is a block diagram showing an outline of the overall configuration of the electronic camera in this embodiment.
This electronic camera is a portable digital still camera that can be carried around. For example, it can be used as a camera for business meetings such as business meetings, debriefing meetings, and council meetings at companies. This is a document camera that shoots postcard information such as letters, figures, and images written on postcards, catalogs, whiteboards, etc., but in addition to shooting document information, people, landscapes, etc. It can also be used as a normal camera for photographing general subjects.

This digital still camera is characterized in that when document information is to be photographed, the document information can always be photographed in the optimum state without careful manual adjustment of the photographing state at that time. is there. In other words, the document information can be photographed in an optimum state without strict manual adjustment of the direction in which the lens is directed to the document information that is the subject, the zoom magnification, and the focus.
Before detailed description of the features of this embodiment, the hardware configuration of this embodiment will be described below.

  The CPU 1 is a central processing unit that controls the overall operation of the digital still camera according to the operating system and various application software in the storage unit 2. The storage unit 2 is a fixed memory such as a hard disk, and has a program storage area and a data storage area. In the program storage area in the storage unit 2, an application program for realizing the present embodiment is stored according to an operation procedure shown in FIGS. The program and data are loaded into the work memory 3 as necessary, and the data in the work memory 3 is saved in the storage unit 2. The recording medium 4 is a detachable memory such as a DVD, and exchanges programs and image data with the storage unit 2 and the work memory 3.

On the other hand, an operation unit 5, a display unit 6, and a camera photographing unit 7 which are input / output peripheral devices are connected to the CPU 1 via a bus line, and the CPU 1 operates these input / output devices according to an input / output program. Take control.
In addition to the shutter button ST and zoom button WD, the operation unit 5 has various function buttons such as a mode button MD for switching to a normal mode / document mode, which will be described later, a release button RS, and the operation signal is given to the CPU 1. The display unit 6 is, for example, a liquid crystal display unit with a touch panel, and is used as a monitor screen / finder screen / image reproduction screen.

  The camera photographing unit 7 includes a photographing lens, a lens / mirror block such as a mirror, an image pickup device such as a CCD image sensor, a driving system thereof, and the like. The CPU 1 adjusts and controls the optical zoom function, and the direction of the lens. Adjusts (shooting direction), controls drive during autofocus, shutter drive control, exposure, white balance, etc. That is, FIG. 2 is a diagram showing a detailed configuration of the camera photographing unit 7. The camera photographing unit 7 includes a photographing lens 71, a photographing control unit 72, and an imaging processing unit 73, and the CPU 1 includes a photographing control unit. The zoom driving control, the focus driving control, the exposure driving control, and the shutter driving control are performed with respect to 72, and the direction of the photographing lens 71 is driven and adjusted to adjust the photographing direction. Driving in the left / right / up / down directions adjusts the shooting direction. Note that the CPU 1 takes a photographed image from the CCD image sensor in the imaging processing unit 73 via the image memory 8 and records and saves it on the recording medium 4.

  Here, the above-described mode button MD is for switching between the normal mode and the document mode, and the “normal mode” is an operation mode for normal photographing of a general subject such as a person or a landscape. In addition, the “Document Mode” allows you to always shoot the document information in the optimal state without manually adjusting the shooting state (optical zoom, shooting direction) when shooting the document information that is the subject of shooting. Therefore, this is an operation mode for performing drive control of the optical system. In this case, by automatically adjusting the shooting conditions of the document information, various correction processes determined in advance are performed on the image actually shot in an optimal state, and then the image is recorded and saved. .

  That is, in the “document mode”, when a monitor image obtained by provisionally photographing an object to be photographed before actual photographing is obtained, the CPU 1 analyzes the monitor image to include a predetermined shape (for example, a square), In addition, it is determined whether or not to capture the document information based on whether or not a character string is included in the area of the predetermined shape. If the image of the document information is captured, the image portion of the predetermined shape is used as the document area. In addition to specifying and changing the shooting condition of the document information by driving the optical system so that the document area is in a predetermined state with respect to the monitor image area, the image actually taken under this shooting condition On the other hand, this is an automatic shooting mode in which various correction processes are performed and stored.

  Here, when there are a plurality of document areas in the monitor image, the CPU 1 specifies a document area located at the center of the monitor screen from among the plurality of document areas, or at the center of the monitor screen. The located document area is specified. The CPU 1 identifies and displays the automatically specified document area in the monitor image. When the document area is identified and displayed, when the user designates the document area as an imaging target, the imaging condition of the document information is displayed. Is adjusted automatically. In this case, the lens orientation (shooting direction) is automatically adjusted so that the document area is located at the center of the monitor image frame, or the document area is within the monitor image frame and is approximately the same as the frame size. The optical zoom is automatically adjusted so that

  Then, when performing various correction processes on the image actually captured after automatic adjustment and recording and saving, the CPU 1 extracts a document area from the actually captured image, and the entire document area is rectangular (for example, After executing the form optimization process (angle correction process and trapezoidal correction process) that corrects the entire shape so that it becomes a rectangular), a predetermined image from the rectangular document area corrected by this form optimization process A filtering process for extracting information is executed. Furthermore, a color tone correction process for correcting the color tone is executed so that the extracted image information can be read clearly and recorded and stored.

FIGS. 3 and 4 are diagrams for explaining how to automatically adjust the direction (shooting direction) of the photographic lens so that the document area is in an optimal state with respect to the monitor image frame.
Here, when the center point of the monitor image is the origin of the XY coordinate system, the CPU 1 obtains the center point of the document area including the document information and compares the center point of the document area with the origin. Thus, the deviation direction of the document area and the deviation ratio thereof are obtained, and the deviation ratio is within an allowable range, i.e., whether the document area is in the central portion of the monitor image frame is checked. It is determined whether or not the area is in an optimal state, and the shooting direction is automatically adjusted so that the document area is positioned at the center of the frame area of the monitor image.

  In the figure, the “bias ratio” indicates the ratio that the center point of the document area is biased with respect to the origin in association with the horizontal and vertical directions. In the example of FIG. In the example of vertical 0%, FIG. 3B shows the case of horizontal 0%, vertical 0%, and in the example of FIG. 3C, horizontal -60% and vertical -40%. In this case, assuming that the allowable range is within ± 20%, in the case of FIGS. 3A and 3C, it is outside the allowable range, and the photographing direction is automatically adjusted according to the deviation direction and the deviation ratio. FIG. 4 shows that when the document area is deviated in the +/− direction of the X axis, the lens direction (shooting direction) is automatically adjusted to the left / right direction according to the deviating direction and the deviating ratio. Show.

FIGS. 5A to 5E are diagrams illustrating a process of automatically adjusting the optical zoom while automatically adjusting the shooting direction so that the document area is in an optimal state with respect to the monitor image frame.
FIG. 5A shows a monitor image acquired first, and FIG. 5B shows a state in which the optical zoom is zoomed in step by step. Here, the CPU 1 checks whether or not the document area protrudes from the monitor image frame while zooming in the optical zoom step by step so that the document area is in an optimal state with respect to the monitor image frame. In the example of 5 (B), since it is a case of protruding, the deviation direction and the deviation ratio of the document area are obtained, and it is checked whether the deviation ratio exceeds the allowable range.

  In this case, in the example of FIG. 5B, since the deviation ratio exceeds the allowable range, whether or not the document area protrudes again after adjusting the photographing direction according to the deviation direction and the deviation ratio. Check. FIG. 5C shows an image after the shooting direction is adjusted. In this case, since the document area is within the monitor image frame, one more zoom-in is performed. FIG. 5D shows the image after zooming in. In this case as well, since the document area is within the monitor image frame, when one more stage of zooming in is performed, as shown in FIG. The deviation ratio is within the allowable range, but the document area is protruded. In this case, by performing one-stage zoom-out, the state returns to the state of FIG. 5D and the document area is automatically adjusted so as to be the maximum size with respect to the monitor image frame.

  FIG. 6 shows that when specifying a document area, if the document area cannot be specified from the monitor image acquired first, the document area is specified while gradually zooming out the optical zoom. FIG. That is, when specifying a document area, even if a character string is included in an area of a predetermined shape in the monitor image acquired first, the area is too large to recognize the entire shape (rectangle). In some cases (see FIG. 6 (A)), it is impossible to specify the document area. In such a case, the contour portion having a specific shape is found while gradually zooming out the optical zoom. The quadrangle of the overall shape is recognized (see FIG. 6B). Also in this case, the document area is automatically adjusted so as to be the maximum size with respect to the monitor image frame.

  Next, the operation concept of the digital still camera in this embodiment will be described with reference to the flowcharts shown in FIGS. Here, each function described in these flowcharts is stored in the form of a readable program code, and operations according to the program code are sequentially executed. In addition, the operation according to the above-described program code transmitted via the transmission medium can be sequentially executed. In other words, in addition to the recording medium, the program / data supplied externally via the transmission medium can be used to execute the operation specific to this embodiment.

7 to 12 are flowcharts showing the overall operation of the digital still camera that is started when the shooting switch is turned on.
First, when the photographing switch is turned on, the CPU 1 initializes the normal mode (step S1), acquires a monitor image from the camera photographing unit 7 and sets it in the image memory 8 (step S2). Display output on the screen (step S3). Here, the presence / absence of a button operation is checked (step S4), and the process returns to step S2 until a certain button is operated and enters a standby state. When a button operation is detected, the type of the operation button is determined, It is checked whether the mode button MD has been operated (step S5), the zoom button WD has been operated (step S6), and whether the shutter button or other buttons have been operated (step S7).

  When the zoom button WD is operated in the normal mode at the initial setting (YES in step S6), the optical zoom drive is controlled according to the zoom-in / zoom-out operation (step S8). In the normal mode, when the shutter button is operated (YES in step S7), the photographed image at the time of the shutter operation is acquired from the image memory 8 and data compression is performed according to the orthogonal transform method (discrete cosine transform method). Thereafter (step S9), a normal operation for recording and saving the compressed image on the recording medium 4 is performed (step S10). In the normal mode, when other buttons are operated (NO in step S7), other processes corresponding to the operation buttons are executed (step S11), and the process returns to the monitor image acquisition process (step S2). ).

  When the mode button MD is operated in the normal mode (YES in step S5), the normal mode is switched to the document mode (step S12). Then, the process proceeds to step S21 and subsequent steps in FIG. 8, and it is determined whether or not the document information is photographed. That is, a monitor image at the time of switching to the document mode is obtained from the image memory 8, and by analyzing the monitor image, it is searched whether or not a specific shape (rectangular) region is included in the monitor image region. The presence or absence of the area is checked (step S22). In this case, reference is made to the characteristic information of the document area that has been set in advance, that is, the shape characteristic (for example, quadrilateral) of the business card, postcard, catalog, whiteboard, etc., and there is an image part with a shape that matches this characteristic information. Check if you are doing.

  Here, when a region having a specific shape is included in the monitor image, it is checked whether or not character information is included in the image portion having the specific shape (step S23). Here, if character information is included in the region of the specific shape (YES in step S23), the region is recognized as a monitor image obtained by photographing the document information, and the region of the specific shape is specified as the document region. (Step S24). When the document area is specified in this way, the process proceeds to step S51 and subsequent steps in FIG. 10, but when the specific shape (rectangle) is not included in the monitor image (NO in step S22), that is, the document area is set. If it cannot be identified, it is checked whether or not character information is included in the monitor image (step S28). Here, if character information is included in the monitor image, there is a possibility that the area of the specific shape is too large to recognize the entire shape as shown in FIG. The current zoom setting state is checked, and it is checked whether or not the zoom-out maximum value (minimum magnification) is set (step S29). If it is less than the zoom-out maximum value (NO in step S29), The optical zoom is zoomed out by one step (for example, 0.5 times), and focus control is performed (step S30).

  When the document area is photographed at a reduced size, the CPU 1 obtains the monitor image immediately after zooming out from the camera photographing unit 7 and sets it in the image memory 8 (step S27), and the monitor image in the image memory 8 is displayed. Analysis is performed to check whether or not there is a region having a specific shape (steps S21 and S22). Hereinafter, the specific shape can be recognized by repeating the zoom-out drive for each step, and when it is recognized that the character information is included in the area, the area of the specific shape is set as the document area. Specify (step S24).

  If the monitor image includes a specific shape but no character information is included in the area (NO in step S23), the character information is too small and can be accurately recognized. Since there is a possibility that it has not, the process proceeds to step S25, where the current set state of the optical zoom is checked, whether or not the zoom-in maximum value (maximum magnification) is set is checked, The optical zoom is zoomed in only by one stage, and focus control is performed (step S26). Then, the monitor image immediately after zooming in is acquired from the camera photographing unit 7 and set in the image memory 8 (step S27), and the monitor image in the image memory 8 is analyzed to check for the presence or absence of an area of a specific shape (step S21, S22). Hereinafter, by repeating zoom-in driving for each stage, a specific shape can be recognized, and when it can be recognized that character information is included in the region, the region of this specific shape Is specified as the document area (step S24).

  If the document area cannot be specified (YES in steps S25 / S29), the process proceeds to step S31 in FIG. 9 to cancel the zoom drive and return to the standard state. An image is acquired and set in the image memory 8 (step S32) and displayed on a monitor (step S33). Thereafter, in a state of waiting for button operation or waiting for a predetermined time from the current monitor display (steps S34 and S35), when the mode button MD is operated (step S36), the document mode is switched to the normal mode. Thereafter (step S37), the process proceeds to step S2 in FIG. 7. When a predetermined time has elapsed, the process returns to step S21 in FIG. 8, and the same operation is performed thereafter.

  On the other hand, when the document area can be specified, in step S51 of FIG. 10, the number of the document areas specified in the monitor image is counted to check whether it is one. The document area is specified as a photographing target (step S52). If there are a plurality of document areas, the presence / absence of the document area located in the central portion of the monitor image is checked (step S53). Although it is specified as a target (step S54), if there is no document area at the center of the monitor image, the size of each document area is obtained and compared (step S55), and the maximum size document area is determined. It is specified as a shooting target (step S56). After the document area to be imaged is specified in this way, the monitor image is fixedly displayed (display locked) (step S57), and then the outline portion of the image area to be imaged is identified and displayed by a bold line (step S58). .

  Here, when the mode button MD is operated (Step S59, S60) while waiting for button operation or waiting for the elapse of a predetermined time from the current monitor display (Steps S59, S60) (Step S61), the document mode is switched to the normal mode. After canceling the monitor fixed display (step S62), the process proceeds to step S2 in FIG. When the predetermined time has elapsed (YES in step S60), the monitor fixed display is canceled (step S64), the monitor image is acquired from the camera photographing unit 7 and set in the image memory 8 (step S65). After the monitor display (step S66), the process proceeds to step S21 in FIG. If the release button RS is operated (YES in step S63), the process proceeds to step S71 in FIG. 11, and processing for automatically adjusting the optical zoom and the shooting direction is performed.

  That is, the current set state of the optical zoom is checked, and on condition that the zoom-in magnification is less than the maximum value (step S71), the optical zoom is zoomed in by one stage and the focus control is performed (step S72). . When the document area is enlarged and photographed in this way, the CPU 1 acquires the monitor image immediately after zooming in from the camera photographing unit 7 and sets it in the image memory 8 (step S73), and analyzes the monitor image in the image memory 8 Then, it is checked whether or not the document area overflows (protrudes) from the monitor image frame (step S74). If the document area is within the monitor image frame (NO in step S75), the process returns to step S71 described above.

  Thereafter, until the zoom-in magnification reaches the maximum value (step S71) or until the document area overflows from the monitor image frame (step S75), the written image in the image memory 8 is sequentially updated while the optical zoom is driven to zoom in step by step. I will do it. If the zoom-in magnification reaches the maximum value before the document area overflows from the monitor image frame (YES in step S71), the process proceeds to step S81 in FIG. 12, but before the zoom-in magnification reaches the maximum value. If the document area overflows from the monitor image frame (YES in step S75), the center point of the document area is obtained as shown in FIG. 3, and the center point of the document area and the origin of the monitor image frame are determined. To determine the deviation direction of the document area and the deviation ratio thereof (step S76), and by checking whether this deviation ratio is within an allowable range, that is, whether the document area is at the center of the monitor image frame. It is determined whether or not the document area is in an optimal state with respect to the monitor image (step S77).

  In this case, for example, when the image of FIG. 5A is zoomed in one step and the deviation ratio exceeds the allowable range as shown in FIG. 5B (YES in step S77), the deviation direction and The photographing direction is automatically adjusted according to the deviation ratio (step S78). Then, the process returns to step S73, and the monitor image after the photographing direction is automatically adjusted is acquired and analyzed to check whether the document area overflows. In this case, as shown in FIG. 5 (C), when the document area after adjusting the photographing direction is within the monitor image frame, one more zoom-in is performed on condition that the zoom-in maximum value is not satisfied. . Hereinafter, when the document area is within the monitor image frame and the zoom-in is performed step by step on the condition that the zoom-in maximum value is not satisfied, for example, as shown in FIG. (Step S75) On the condition that the deviation ratio is within the allowable range (Step S77), one-stage zoom out is performed (Step S79). Thus, the state shown in FIG. 5E is returned to the state shown in FIG.

  After the optical zoom and the shooting direction are automatically adjusted in this way to set the document area to an optimum state, the process proceeds to step S81 in FIG. 12 to acquire a monitor image from the camera shooting unit 7 and store it in the image memory 8. In addition to setting the image data acquired from the image memory 8 in the work memory (processing memory) 3 (step S32), the document area is specified in the processing memory while analyzing the entire photographed image. An area is extracted (step S83). Then, the CPU 1 performs angle correction on the extracted document area (step S84). For example, when taking a rectangular business card, if it is taken from an oblique direction without taking it from directly above, the entire shape of the business card is taken in a trapezoidal state due to the difference in perspective from the camera position. Thus, when the document area is photographed with an inclination, angle correction is performed to rotate the document area in accordance with the inclination. FIG. 13A shows the extracted document area, and FIG. 13B shows the image after angle correction. Next, trapezoid correction is performed to correct the document area (trapezoid) after angle correction to the original square (rectangular) (step S85). FIG. 13C shows an image after keystone correction.

  In this case, in order to match the short side (portion corresponding to the upper side) of the trapezoid with the long side (portion corresponding to the lower side), the print region is expanded and the print region is corrected to the original rectangle (rectangle). When the form optimization process of the document area is executed in this way, a filtering process for extracting predetermined image information (for example, image information such as characters) is executed together with noise removal from the corrected rectangular document area. (Step S87), and further, a tone correction process is performed to correct the hue so that the extracted image information can be read clearly (Step S88).

  Then, after the image in the processing memory is displayed on the monitor (step S89), the presence / absence of button operation is checked (step S90). Here, when the release button RS is fully pressed (YES in step S91), the image in the processing memory is subjected to data compression according to the orthogonal transformation method, and the compressed image is recorded and stored in the recording medium 4. (Step S92) A monitor image is acquired from the camera photographing unit 7 and set in the image memory 8 (Step S94), and is displayed on the monitor (Step S95). If the release button RS is pressed halfway (YES in step S93), a monitor image is acquired from the camera photographing unit 7 and set in the image memory 8 (step S94), and displayed on the monitor (step S95). ). Then, the process proceeds to step S21 in FIG.

  As described above, in the digital still camera of this embodiment, the CPU 1 has the document mode and the normal mode. In the document mode, the monitor image is analyzed to display the region including the document information in the monitor image. When the document area is instructed to be photographed in the state where the document area is identified and displayed on the monitor screen, the document area is in a predetermined state with respect to the monitor image area. As described above, since the shooting control unit 72 of the camera shooting unit 7 is driven and controlled to change the shooting condition of the document information, it can be used as a normal camera or a document camera for shooting the document information. When using it, you can always shoot the document information in the optimum state without carefully adjusting the shooting state of the document information. It is possible to shoot while confirming the intention of the photographer, greatly reducing the burden on the photographer, and further, when performing various corrections on the image shot in the optimum state, the correction can be performed accurately. It becomes possible.

In this case, when there are a plurality of document areas, the CPU 1 identifies a document area having the maximum size among the plurality of document areas or a document area located at the center of the monitor screen. Therefore, when specifying the document area from the monitor image, it is possible to automatically specify the document area having a high probability.
Further, when the specified document area is identified and displayed on the monitor screen, the outline portion of the area is identified and displayed, so that the automatically specified document area can be easily confirmed.

  On the other hand, when the CPU 1 analyzes the monitor image and specifies the area including the document information in the monitor image as the document area, if the document area cannot be specified, the CPU 1 controls the drive of the optical system. Repeat the operation to re-specify whether or not the document area is included in the monitor screen while changing the shooting condition of the document information, and if the document area can be identified as a result, the Since the optical system is driven and controlled so that the document area is in a predetermined state with respect to the monitor image area, the shooting condition of the document information is changed, so even if it is impossible to specify the document area in the original monitor image The document area can be automatically specified without performing any special operation. In this case, if the document area cannot be identified even after repeating the re-identification operation, the optical system is driven and controlled to return to the standard photographing conditions, so that the photographing of the document information is automatically canceled. be able to.

  Furthermore, the CPU 1 analyzes the monitor image so as to specify the document area based on whether or not the image portion of the predetermined shape is included in the monitor image, so that the standard paper such as business cards and postcards, A business card, a postcard, and a whiteboard imaged part can be easily specified as a document area based on a predetermined shape (for example, a rectangle) from a monitor image obtained by photographing a standard object such as a whiteboard or bulletin board. Also, by analyzing the monitor image, the document area is specified based on whether or not the character string is included in the monitor image. Even if it appears accidentally or mistakenly, it can be processed out of the target of the document area, and the specification of the document area becomes more reliable.

  In this case, when the document area is located at a biased position in the monitor image area, the CPU 1 drives and controls the optical system so that the document area is located at the center of the monitor image area. Thus, it is possible to always shoot the document area at an appropriate position. When the document area is smaller than the maximum size of the monitor image area, the optical system is driven and controlled so that the document area is within the monitor image area and is equal to the area size. Since it is changed, it is always possible to shoot at the maximum magnification.

  Then, after changing the shooting condition of the document information by driving the optical system so that the document area is in a predetermined state with respect to the monitor image area, the inside of the document area shot under the changed shooting condition Therefore, it is possible to obtain a high-quality image in which distortion and the like are corrected. Here, in a state where the image in the document area after the correction is displayed on the monitor screen, the image is recorded and saved on a recording medium according to the recording instruction of the image, and the document area is stored according to the cancellation instruction of the image. Since it was canceled as a non-shooting target, the user's intention can be taken into consideration.

  In addition, when document information is photographed under automatically adjusted photographing conditions, a form optimization process is performed to correct the shape of the document region so that the entire document region becomes a square by analyzing the photographed image. As a result, a high-quality image can be recorded and saved, and a filtering process for extracting predetermined image information from the rectangular document region corrected by the form optimization process is executed. Only image information can be recorded and saved.

  In the above-described embodiment, when specifying the document area in the monitor image, reference is made to a preset shape characteristic (e.g., quadrangle) and background color such as business cards, postcards, catalogs, and whiteboards. The image portion matching the shape characteristic and the background color is specified as the document area. However, not only the shape of the area and the background color but also, for example, the region configuration characteristic is set as the characteristic information of the document area. You may do it. In addition, when specifying the document area, it is determined whether or not the character information is included in the shape area together with the shape characteristics. However, the document information is not limited to the character information, but includes symbols, figures, It may be an image such as a photograph.

  In the above-described embodiments, the shooting direction is automatically changed by driving and controlling the lens direction, or the shooting magnification is automatically changed by driving and controlling the optical zoom. Further, the exposure may be automatically changed by driving the aperture.

  In the above-described embodiment, when recording and saving an image actually taken under the shooting conditions after automatic adjustment, only the image extracted from the document area is recorded and saved. The entire photographed image actually taken below may be recorded and saved, or only the document area extracted from this photographed image may be recorded and saved.

  In the embodiment described above, after performing the form optimization process, the filtering process for extracting predetermined image information from the rectangular document region corrected by the form optimization process is performed, and the extracted image information is Although the color tone correction process for correcting the color tone so that it can be read clearly is executed, the filtering process and the color tone correction process may be performed by another electronic device such as a personal computer.

  Furthermore, in the above-described embodiment, the present invention is applied to a portable document camera for a business meeting for photographing various materials, business cards, postcards, catalogs, whiteboards, etc. at business meetings, debriefings, and councils. Although the case has been shown, as a projector option, a document camera attached to the document table via an arm may be used. In this case, the document camera can be removed from the projector, and a whiteboard or the like may be photographed. Furthermore, it is of course applicable not only for business meetings but also for general purposes. .

  On the other hand, a recording medium (for example, a CD-ROM, a flexible disk, a RAM card, etc.) on which program codes for executing the above-described units are recorded may be provided to the computer. That is, a recording medium having a program code that can be read by a computer, and in a document shooting mode, a function for specifying an area including document information in a monitor image by analyzing the monitor image as a document area A function for identifying and displaying the document area on the monitor screen and when the document area is instructed to be photographed when the document area is identified and displayed, the document area is in a predetermined state with respect to the monitor image area. It is also possible to provide a computer-readable recording medium that records a program for realizing a function of changing the photographing condition of the document information by driving and controlling the optical system.

  In addition, a computer-readable recording medium having a program code, the monitor image is analyzed to specify a region including the document information in the monitor image as a document region, and the optical system is driven to control the document Whether the document area is included in the monitor screen while changing the shooting condition of the document information by controlling the optical system when the function to change the shooting condition of the information and the document area cannot be specified If the document area can be identified as a result, the optical system is driven so that the identified document area is in a predetermined state with respect to the monitor image area. You may make it provide the computer-readable recording medium which recorded the program for implement | achieving the function to control and change the imaging conditions of document information.

The block diagram which showed the outline | summary of the whole structure of an electronic camera. The figure which showed the detailed structure of the camera imaging | photography part 7. FIG. FIGS. 9A to 9C are diagrams for explaining how to automatically adjust the direction (shooting direction) of the photographic lens so that the document area is in an optimum state with respect to the frame area of the monitor image. . FIG. 6 is a diagram showing that when the document area is biased in the +/− direction of the X axis, the lens orientation (photographing direction) is automatically adjusted to the left / right according to the bias direction and the bias ratio. FIGS. 9A to 9E are diagrams illustrating a process of automatically adjusting an optical zoom while automatically adjusting a shooting direction so that a document area is in an optimum state with respect to a monitor image frame. FIGS. FIG. 5 is a diagram showing specifying a document area while gradually zooming out an optical zoom when the document area cannot be specified from the monitor image acquired first when specifying the document area. The flowchart which showed the whole operation | movement of the digital still camera started when a photography switch is turned on. The flowchart which showed the whole operation | movement of the digital still camera following FIG. The flowchart which showed the whole operation | movement of the digital still camera following FIG. The flowchart which showed the whole operation | movement of the digital still camera following FIG. FIG. 11 is a flowchart illustrating the overall operation of the digital still camera following FIG. 10. FIG. 12 is a flowchart illustrating the overall operation of the digital still camera, following FIG. (A) is a diagram showing an extracted document area, (B) is a diagram showing an image after angle correction, and (C) is a diagram showing an image after trapezoid correction.

Explanation of symbols

1 CPU
2 storage unit 4 recording medium 5 operation unit 6 display unit 7 camera photographing unit 8 image memory 72 photographing control unit 73 imaging processing unit ST shutter button MD mode button

Claims (14)

An electronic camera having a document shooting mode for shooting document information and a standard shooting mode for shooting an arbitrary subject,
In the document photographing mode, a specifying unit that identifies a region including the document information in the monitor image as a document region by analyzing the monitor image;
Identification display means for identifying and displaying the document area specified by the specifying means on the monitor screen;
When the document area is identified and displayed by the identification display means, the optical system is driven so that when the document area is instructed as an object to be photographed, the document area is in a predetermined state with respect to the monitor image area. Control means for controlling and changing the shooting conditions of the document information;
An electronic camera comprising: The specifying unit specifies a document area having a maximum size among the plurality of document areas when there are a plurality of document areas.
The electronic camera according to claim 1, which is configured as described above. The specifying means specifies a document area located in a central portion of the monitor screen among the plurality of document areas when there are a plurality of document areas.
The electronic camera according to claim 1, which is configured as described above. The identification display means, when identifying and displaying the specified document area on the monitor screen, to identify and display the outline portion of the area,
The electronic camera according to claim 1, which is configured as described above. An electronic camera for photographing document information,
A specifying means for specifying a region including the document information in the monitor image as a document region by analyzing the monitor image;
Control means for changing the photographing condition of the document information by driving and controlling the optical system;
When the document area cannot be specified by the specifying means, the monitor area includes the document area while changing the photographing condition of the document information by driving the optical system by the control means. If the document area can be specified as a result, the optical system is set so that the specified document area is in a predetermined state with respect to the monitor image area. To change the shooting conditions for document information,
An electronic camera characterized by that. The specifying means specifies a document area based on whether or not an image portion of a predetermined shape is included in the monitor image by analyzing the monitor image;
6. The electronic camera according to claim 1, wherein the electronic camera is configured as described above. The specifying means specifies a document area based on whether or not a character string is included in the monitor image by analyzing the monitor image;
6. The electronic camera according to claim 1, wherein the electronic camera is configured as described above. The control means drives and controls the optical system so that the photographing direction is located in the central portion of the monitor image area when the document area is located at a biased position in the monitor image area. change,
6. The electronic camera according to claim 1, wherein the electronic camera is configured as described above. When the document area is smaller than the maximum size of the monitor image area, the control means drives and controls the optical system so that the document area is within the monitor image area and is equal to the area size. Change the magnification,
6. The electronic camera according to claim 1, wherein the electronic camera is configured as described above.   After changing the shooting condition of the document information by driving and controlling the optical system so that the document area is in a predetermined state with respect to the monitor image area, the document area in the document area shot under the changed shooting condition 6. The electronic camera according to claim 1, further comprising correction processing means for processing an image. In a state where the image in the document area processed by the correction processing means is displayed on the monitor screen, the image is recorded and stored on the recording medium in accordance with the recording instruction of the image, and the document area in accordance with the instruction to release the image To cancel
The electronic camera according to claim 10, which is configured as described above. If the document area cannot be specified even after repeating the re-specification operation, the optical system is driven and returned to the standard shooting conditions.
6. The electronic camera according to claim 5, wherein the electronic camera is configured as described above. Against the computer,
In the document shooting mode, by analyzing the monitor image, a function for specifying an area including the document information in the monitor image as a document area;
A function for identifying and displaying the specified document area on the monitor screen;
When the document area is identified and displayed, when the document area is instructed to be photographed, the optical system is driven and controlled so that the document area is in a predetermined state with respect to the monitor image area. A function to change the shooting conditions of
A program to realize Against the computer,
A function for identifying an area including document information in the monitor image as a document area by analyzing the monitor image;
A function to drive and control the optical system to change the shooting conditions of document information;
When the document area cannot be specified, the optical system is driven and controlled to change the shooting condition of the document information and repeat the operation to re-specify whether or not the document area is included in the monitor screen. As a result, when the document area can be specified, the optical system is driven and controlled so that the specified document area is in a predetermined state with respect to the monitor image area, thereby changing the shooting condition of the document information. Function to
A program to realize

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