JP4548144B2 - Digital camera device and through image display method - Google Patents

Description

  The present invention relates to a digital camera device and a through image display method.

  In recent years, digital cameras have been used not only for taking pictures of landscapes and people, but also for paper documents, business cards, etc. It is also used as a business tool for taking pictures of a written white board (white board) and storing and managing these images digitally on a PC (personal computer) or the like. When photographing a document or white board in this way, it is desirable to photograph the object in front and vertically.

  However, it is difficult to shoot a document placed on the desk from directly above, and when shooting a white board, it is difficult to shoot it from the front, such as when the shooting location is located diagonally of the white board There is also. Even if it is possible to shoot from the front, it may be preferable to avoid shooting from the front for reasons such as reflection of light. In this way, when an object such as a document is photographed from an oblique direction, characters or the like are distorted obliquely or trapezoidally. Of course, these characters can be read, but they are very tiring to read. Moreover, since these images have distortion, it is difficult to reuse these images.

In this regard, for example, in Patent Document 1 below, trapezoidal distortion present in an image of a document or the like photographed by a camera supported by a support column is assumed to be the inclination of the photographing optical axis with respect to the support column in the camera, that is, the inclination of the photographing optical axis with respect to the document or the like Is described, and a correction method based on the detected inclination is described.
JP 2002-354331 A (see paragraphs “0015” and “0016”)

  However, the above method is effective when the camera is used while being fixed to a document table or the like placed in a predetermined place, but it can be used when shooting an object with a handheld camera. Can not. Therefore, in order to obtain an image without distortion with the camera alone, for example, a rectangular target area such as a white board is detected from the captured image recorded by shooting, the rectangular target area is cut out once, and the distortion is corrected (oblique). It is necessary to provide the camera with a bevel correction function that obtains a rectangular correction image that is the same as the image taken from the front.

  Here, when performing the above-described oblique correction, it is necessary that the contour detection is correctly performed on the photographed image. However, there are variations in the state of the photographed image due to differences in the photographing environment and the like. The contour detection of the area intended by the photographer cannot be performed well, and the target area may fail to be cut out. And when extraction fails, a user is forced to image | photograph a target object again. However, the user can know the failure of cropping after recording a captured image and obtaining a corrected image, and with a general digital camera, recording a captured image requires a certain amount of time. Therefore, it is not possible to immediately confirm whether or not the cutout has succeeded after shooting. Therefore, there has been a problem that it is not always easy to use.

  The present invention has been made in view of such a conventional problem, and in a device provided with a bevel correction function, a digital camera device and a through image display method capable of improving the usability of the function, and its realization. The purpose is to provide a program to be used.

In order to solve the above-mentioned problem, in the invention of claim 1, a digital camera apparatus comprising: an imaging unit that images a subject; and a display unit that displays an image captured by the imaging unit in a shooting standby state as a through image. An outline extracting means for extracting an outline of a rectangular area from a subject image picked up by the image pickup means in response to a first photographing operation based on a predetermined extraction criterion, and an outline extracted by the outline extracting means Based on the correction means for correcting the distortion in the rectangular area that varies depending on the shooting angle, the image recording means for recording the image after the correction processing by the correction means, and the contour extraction means And an extraction control means for extracting the contour from the first image displayed as the through image in the shooting standby state, and predetermined image processing. The displayed first image and the contour line indicating the contour extracted from the first image by the contour extracting unit are displayed as the through image after the first image by the display unit in a shooting standby state. A combining unit that performs a combining process on the second image, a display control unit that displays the third image after the combining process by the combining unit on the display unit as a through image, and a second shooting operation And an imaging control means for imaging the second image .

In such a configuration, the contour extraction of the rectangular region is performed for an image obtained by imaging the subject at an arbitrary time in the shooting standby state, the contour line indicating the extracted contour, and the through line from which the contour line has been extracted. By displaying the image superimposed on the subsequent through image, the photographer can confirm whether the intended contour line for the selected subject can be extracted or not before actually recording the subject. Appropriate projection correction can be performed.

  According to a second aspect of the present invention, the synthesizing unit performs a synthesizing process in which the first image is made semi-transparent and superimposed on the second image together with the contour line.

  In such a configuration, the photographer can confirm both the image when the contour is detected and the image that can be photographed at the same time.

According to a third aspect of the present invention, there is provided an operation means that allows a user to operate the first photographing operation and the second photographing operation.

According to a fourth aspect of the present invention, the display control means causes the display means to display the third image as a through image while the first photographing operation continues, and When one shooting operation is completed, a through image is displayed on the display unit as an image captured by the imaging unit.

In such a configuration, at the stage where the composition of the subject to be photographed is confirmed, whether or not the intended contour line for the subject being selected can be extracted is checked by the photographer before the actual subject is recorded , and thereafter The display state of the contour line can be maintained only for the period required by the photographer.

According to a fifth aspect of the present invention, there is provided a digital camera device that displays a subject image captured in a shooting standby state as a through image, from a subject image captured and stored in response to a first shooting instruction, A digital camera having an oblique correction function that extracts a contour of a quadrangular area based on a predetermined extraction criterion, and performs correction processing on the subject image to correct distortion in the quadrangular area that varies depending on a shooting angle based on the extracted contour. A method of displaying a through image in an apparatus, the step of extracting a contour of a rectangular area from a through image displayed at a predetermined time point based on a predetermined extraction criterion, and a through image displayed after the through image from which the contour has been extracted the image, and displaying by superimposing the through image obtained by extracting the contour predetermined image processing is performed, the contour line indicating the contour, first In response to the shooting instruction, and a method comprising the step of taking a through image to be displayed after the through image obtained by extracting the contour.

According to this method, whether or not the intended contour line for the selected subject can be extracted by displaying the through image from which the contour line has been extracted, the contour line, and the subsequent through image in an overlapping manner is actually determined. By allowing the photographer to check the subject before recording the subject, appropriate projection correction can be performed.

According to a sixth aspect of the present invention, there is provided a digital camera device that displays a subject image captured in a shooting standby state as a through image, from a subject image captured and stored in response to a first shooting instruction, A digital camera having an oblique correction function that extracts a contour of a quadrangular area based on a predetermined extraction criterion, and performs correction processing on the subject image to correct distortion in the quadrangular area that varies depending on a shooting angle based on the extracted contour. the computer apparatus has, from the through image displayed at a predetermined time, the process for extracting the contour of the rectangular region on the basis of a predetermined extraction reference, the through image to be displayed after the through image obtained by extracting the contour, predetermined a through image image processing is to extract the contour has been subjected to the processing for displaying overlapping contours indicating the contour, shooting of the second In response to the instruction, and a program for executing the processing for capturing a through image to be displayed after the through image obtained by extracting the contour.

As described above, in the present invention, whether the intended contour line for the selected subject can be extracted by displaying the contour line, the through image obtained by extracting the contour line, and the subsequent through image superimposed on each other. By allowing the photographer to check before the actual recording of the subject, it is possible to perform appropriate projection correction . Therefore, in the case where the oblique correction function is provided, the usability of the function can be improved.

  In addition, the photographer can simultaneously confirm both the image when the contour is detected and the image that can be photographed at the same time. Therefore, the intended image can be easily taken by matching the current image with the image when the contour is detected, and better usability can be ensured.

  In addition, when the composition of the subject to be photographed is confirmed, the photographer confirms whether or not the intended oblique correction can be performed on the selected subject, and then the outline display state is maintained only for the period required by the photographer. To be able to. Therefore, it is easy to see the through image until the composition of the photographing target is confirmed, and after the composition of the photographing target is confirmed, the composition of the image to be actually recorded can be easily determined using the contour line as a guide. Good usability can be secured.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the appearance of a digital camera 1 according to the present invention and the situation when a white board 51 is being photographed. The digital camera 1 includes a camera body 2 that is a flat housing, and mainly includes a photographing lens unit 3 provided on the front surface of the camera body 2, a photographing button 4 provided on the top surface, and a liquid crystal monitor 5 provided on the back surface. And. The shooting button 4 has a so-called half shutter function, and a mechanism that can perform a half-press operation and a full-press operation, that is, a first operation position (half-press) for shooting notice and a second operation position for shooting instruction. It is the operation means in this invention which has (full press).

  The liquid crystal monitor 5 is composed of a color liquid crystal display panel with a backlight, for example, and functions as an electronic viewfinder in a shooting standby state in a recording mode to display a through image of a subject, while being recorded in a playback mode. It is a display means of the present invention for displaying an image. The liquid crystal monitor 5 also displays various menu screens, setting screens, and the like as necessary.

  FIG. 2 is a block diagram showing an outline of the circuit configuration of the digital camera 1. The digital camera 1 is configured around a CPU 100 that controls the entire system, and the following units are connected. That is, the CPU 100 includes an optical lens device 102 configured with a lens or the like for condensing an optical image of a subject, and an image sensor 103 such as a CCD that is an imaging unit for digitizing and capturing the collected optical image. A display unit 105 including the liquid crystal monitor 5 for displaying a digitized image, an image memory 104 such as a RAM for temporarily storing the captured image, and a trigger for storing the image. The shooting button 4 to be switched and switches 106 such as a mode switching button (not shown) are connected. Note that the operation state of the switches 106 is periodically scanned by the CPU 100.

  Furthermore, the CPU 100 transfers the external storage IO unit 108 that interfaces with the memory card 109 for recording images, the image captured by the image sensor 103, the image recorded on the memory card 109, and the like to the PC. A PC interface block 107, a program code storage unit 101 such as a ROM for storing a program to be executed by the CPU 100, and image processing such as creation of image compression data of a captured image and distortion correction Are connected to each other. In this embodiment, the memory card 109 is the image recording unit of the present invention, and the image processing unit 110 is the contour extracting unit and the correcting unit of the present invention.

  The program code storage unit 101 stores various programs for causing the CPU 100 to control the entire system. In particular, a program for causing the CPU 100 to function as an extraction control unit, a synthesis unit, and a display control unit of the present invention at the time of photographing in a business mode described later is stored.

  Next, an operation according to the present invention of the digital camera 1 having the above configuration will be described. FIG. 3 is a flowchart showing the operation of the digital camera 1 when the business mode, which is a lower mode of the recording mode, is set. The business mode is an operation mode provided in advance for the purpose of cutting out a necessary part from a document such as a paper document or a business card, or an image obtained by photographing a white board, correcting the distortion, and saving the image.

  The digital camera 1, for example, starts the operation in accordance with the power-on operation or the switching operation to the reproduction mode, and first starts through control as shown in FIG. 3 (step S10). That is, by setting the drive of the image sensor 103 to the through mode, a digital image with a low through resolution (hereinafter referred to as a through image) is created from the optical image condensed on the image sensor 103, and this is stored in the image memory. While being periodically stored in 104 (standard is 30 sheets per second), the through image temporarily stored in the image memory 104 is sent to the display unit 105 for display. Then, until the shooting button 3 is half-pressed (NO in step S11), the shooting standby state in which the through image is periodically updated by the above processing is maintained.

  In the meantime, the user confirms the through image, and when the image that the user wants to shoot is displayed, the imaging button 4 is pressed halfway, and when the CPU 100 detects it (YES in step S11), the CPU 100 detects the image memory 104. While the transmission of the through image is temporarily stopped, the image processing unit 110 is caused to detect the contour from the through image at that time (step S12). In such contour detection, for example, straight line recognition is performed on a through image, a plurality of rectangular regions partitioned along the recognized plurality of straight lines are detected, and the contour line of the rectangular region having the largest area is acquired. The contour is detected based on a predetermined extraction criterion such as.

  Subsequently, the CPU 100 copies the through image subjected to the contour detection to a predetermined area in the image memory 104, temporarily saves it, resumes sending the through image to the image memory 104, and is shown in FIG. As described above, the image of the contour line A (transparent background) 201 detected by the image processing unit 110 is combined with the new (current) through image 203 together with the through image 202 at the time of contour detection (step). S13). At this time, the through image 202 at the time of contour detection is subjected to a translucent process by a predetermined method such as transparentizing a predetermined ratio of pixels and reducing the luminance of the remaining pixels. Thereafter, the synthesized composite image 204 (see FIG. 5) is sent to the display unit 105 for display (step S14).

  Thereafter, while the imaging button 4 is pressed halfway (both NO in steps S15 and S16), only the portion of the current through image 203 captured by the image sensor 103 is repeated by repeating the processing in steps S13 and S14. The composite image 204 in which changes is periodically displayed. In the meantime, when the half-press of the imaging button 4 is stopped (YES in step S15), the process returns to step S11 to display and update a normal through image.

  Then, while the composite image 204 is displayed as shown in FIG. 5, the user confirms that the contour of the target is correctly displayed by the displayed contour line A, and the translucent image whose contour is detected. The shooting range is adjusted so that the current through image matches, and the shooting button 3 is fully pressed. On the other hand, when the CPU 100 detects that the shooting button 3 has been fully pressed (YES in step S16), it instructs the image sensor 103 to read an image with a high resolution instead of a through image (step S17). This high resolution image is sent to a predetermined area in the image memory 104 at an address different from that of the through image described above. When the CPU 100 confirms that the image transfer has been completed (YES in step S18), the CPU 100 creates a low-resolution preview image from the captured image (high-resolution image) and displays it on the preview image address in the image memory 104. (Step S19), and the image photographed thereby is displayed on the display unit 105 as a freeze display for a predetermined time.

  Subsequently, the CPU 100 creates compressed data such as JPEG using the image processing unit 110 (step S20), and stores the captured image compressed data in the memory card 109 via the external storage IO unit 108 (step S21). . Next, the image processing unit 110 again extracts the bevel parameters for creating a front image from the photographed image (step S22). If the bevel parameters can be extracted (YES in step S23), the image processing apparatus further performs the extraction. Then, a bevel correction image is created using the bevel parameters, the compressed image data is also created by the image processing apparatus for the created image, and the created bevel correction image is stored in the memory card 19 (steps S24 to S26). . If the bevel parameter cannot be extracted for some reason in step S22 described above (NO in step S23), a warning process informing that effect, for example, a message indicating that correction cannot be performed is performed.

  Thereafter, the CPU 100 ends a series of shooting processes and performs the next mode process again, but the digital camera 1 repeats the above-described operation again while the user does not perform a key operation or the like.

As described above, in the digital camera 1 of the present embodiment, when a subject is photographed in the business mode, the contour detection is performed using the through image at that time when the photographing button 3 is half-pressed, and the detection result is obtained. Whether or not the photographer can extract and save the intended area by combining the contour line A and the through image 202 from which the contour line is to be extracted with the current through image 203 and displaying it. Can be notified at the stage before shooting. Therefore, there is no useless shooting operation when the intended area cannot be cut out, and there is no need to wait for a useless shooting operation for re-shooting, and it is possible to ensure good usability.

Further, when the contour line A is displayed, the through image that is the object of contour detection is displayed as a semi-transparent layer on the current through image, so that the photographer can use both the image when the contour is detected and the image that can be currently captured. Can be confirmed at the same time. Therefore, as described above, the photographer can easily shoot the intended image by matching the current image with the image when the contour is detected, thereby ensuring good usability.

  In the present embodiment, the one that displays the contour line A or the like in response to the half-press of the photographing button 3 is shown. However, for example, a dedicated operation button for displaying the contour line A or the like in the photographing standby state is shown. Alternatively, the same function may be assigned to an existing operation button other than the shooting button 3. Further, for example, in the configuration in which the photographing button 3 does not have a half shutter function, the above-described contour detection and contour line A display may be automatically performed at regular intervals. In that case, it is better that the user can set the display interval of the contour line A or the like in advance.

Further, as in the present embodiment, when the photographing button 3 is half-pressed, contour detection is performed using the through image at that time, and the contour line A that is the detection result and the contour line are extracted. By combining the through image 202 with the current through image 203 and displaying it, the user compares the displayed outline A with the original through image 202 to determine whether or not the intended outline has been cut out. This can be easily determined, and at the time of photographing, the intended range can be easily photographed by comparing the original through image 202 or the contour line A with the current through image 203 as a guide.

  In addition, as described above, it is possible to notify the photographer whether or not the intended area can be cut out and stored, and there is no need to re-shoot, so that, for example, the recording mode can be used. In addition to the business mode described above, an operation mode is provided in which only the above-described contour line A or the like is displayed in response to a half-press of the shooting button 3, and is already stored in the lower level of the playback mode. It is also possible to provide an operation mode for creating and saving a bevel correction image from the recorded image. In that case, it is possible to acquire a bevel-corrected image even from an image photographed by another digital camera as long as the same model is used.

  Although the case where the present invention is applied to a general digital camera has been described here, the present invention is also applied to other digital cameras incorporated in other devices such as a mobile phone. can do.

It is a figure which shows an example of the external appearance of the digital camera which concerns on this invention, and its use condition. It is a block diagram which shows the circuit structure of the digital camera. It is a flowchart which shows the imaging | photography process by CPU when the business mode is set. It is explanatory drawing of the synthesized image displayed while a photographing button is half-pressed. It is a figure which shows the example of the same synthesized image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Digital camera 2 Camera body 3 Shooting lens part 4 Shooting button 5 Liquid crystal monitor 51 White board 100 CPU
DESCRIPTION OF SYMBOLS 101 Program code memory | storage device 102 Optical lens apparatus 103 Image sensor 104 Image memory 105 Display part 106 Switches 107 PC interface block 108 External memory | storage IO part 109 Memory card 110 Image processing part 202 Through image 203 (at the time of outline detection) ) Through image 204 Composite image A Contour line

Claims (6)

A digital camera apparatus comprising: an imaging unit that images a subject; and a display unit that displays an image captured by the imaging unit in a shooting standby state as a through image,
Contour extracting means for extracting a contour of a quadrangular area from a subject image captured by the imaging means in response to a first photographing operation based on a predetermined extraction criterion;
Correction means for performing correction processing on the subject image to correct distortion in the rectangular region that differs depending on the shooting angle based on the contour extracted by the contour extraction means;
Image recording means for recording an image after correction processing by the correction means;
Extraction control means for causing the contour extraction means to extract the contour from the first image displayed as the through image in a shooting standby state;
The first image that has been subjected to the predetermined image processing and the contour line that indicates the contour extracted from the first image by the contour extraction unit are displayed by the display unit in a shooting standby state, rather than the first image. Combining means for performing a combining process to be superimposed on a second image to be displayed later as the through image;
Display control means for causing the display means to display the third image after the composition processing by the composition means as a through image;
A digital camera apparatus comprising: an imaging control unit that captures a second image in response to a second imaging operation .   2. The digital camera apparatus according to claim 1, wherein the synthesizing unit performs a synthesizing process of superposing the first image on the second image together with the contour line in a semi-transparent state. The digital camera device according to claim 1, further comprising an operation unit that allows a user to operate the first photographing operation and the second photographing operation . The display control means causes the display means to display the third image as a through image while the first photographing operation is continued, and causes the display means to display the first photographing operation when the first photographing operation ends. 4. The digital camera device according to claim 1 , wherein a through image is displayed on the image picked up by the image pickup means . A digital camera device that displays a subject image captured in a shooting standby state as a through image, and extracts a contour of a rectangular region from a subject image captured and stored in response to a first shooting instruction based on a predetermined extraction criterion The display method of the through image in the digital camera device having a slant correction function for performing correction processing on the subject image, which corrects distortion in the rectangular region that varies depending on the shooting angle based on the extracted contour,
A step of extracting the outline of the rectangular region based on a predetermined extraction criterion from the through image displayed at a predetermined time point;
A step of displaying the through image obtained by extracting the outline subjected to predetermined image processing on the through image displayed after the through image from which the outline has been extracted, and the contour line indicating the outline,
Capturing a through image to be displayed after the through image from which the contour has been extracted in response to a second imaging instruction . A digital camera device that displays a subject image captured in a shooting standby state as a through image, and extracts a contour of a rectangular region from a subject image captured and stored in response to a first shooting instruction based on a predetermined extraction criterion And a computer having a digital camera device having an oblique correction function for performing correction processing on the subject image to correct distortion in the rectangular region that differs depending on the shooting angle based on the extracted contour.
A process for extracting the outline of the quadrangular region based on a predetermined extraction criterion from a through image displayed at a predetermined time;
A process for displaying the through image obtained by extracting the outline subjected to predetermined image processing on the through image displayed after the through image from which the outline has been extracted, and the outline indicating the outline;
A program for executing processing for capturing a through image to be displayed after the through image from which the contour has been extracted in response to a second imaging instruction .

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