Patent Publication Number: US-2003235399-A1

Title: Imaging apparatus

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to an imaging apparatus, and in particular to an apparatus for recording information of a photographing position together with image data, at the time of photographing.  
       [0003] 2. Related Background Art  
       [0004] In a conventional image recording and reproducing apparatus, as described in Japanese Patent Application Laid-open No. 7-320457, in order to reproduce an image recorded in advance and an image recorded later in association with each other, association information is prepared to link the images with each other at the time of recording.  
       [0005] However, in the conventional example, in associating an existing image and an image recorded anew, a user adds association information manually while looking at the images. Thus, considerable time and labor are required for realizing simple image retrieval using a link function.  
       SUMMARY OF THE INVENTION  
       [0006] It is an object of the present invention to solve the problem as described above.  
       [0007] It is another object of the present invention to make it possible to easily retrieve a desired image out of a large number of images.  
       [0008] In order to solve the above-mentioned problem and attain the above-mentioned objects, the present invention presents, as an aspect thereof, an imaging apparatus including: image pickup means; location detection means for detecting a present location and outputs photographing position information; recording means for recording image data obtained by the image pickup means and the photographing position information outputted from the location detection means in association with each other on a recording medium; and retrieval means for, based upon representative location information corresponding to representative image data and photographing position information corresponding to a plurality of image data recorded on the recording medium, retrieving image data relating to the representative image data among the plurality of image data recorded on the recording medium.  
       [0009] Other objects and features of the present invention will be apparent from the following detailed description of embodiments of the present invention taken in conjunction with the accompanying drawings.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0010] In the accompanying drawings:  
     [0011]FIG. 1 is a diagram showing a video camera;  
     [0012]FIG. 2 is a diagram showing a format of a photographed image data;  
     [0013]FIG. 3 is a diagram showing a format of guide page data;  
     [0014]FIG. 4 illustrates a display example of a guide page;  
     [0015]FIG. 5 is a flowchart showing operations of a first embodiment;  
     [0016]FIG. 6 is a flowchart showing retrieval processing of a photographing range;  
     [0017]FIG. 7 illustrates a relation between a map and location information;  
     [0018]FIG. 8 is a flowchart showing other retrieval processing of the first embodiment;  
     [0019]FIG. 9 illustrates-a relation between a map and location information;  
     [0020]FIG. 10 is a flowchart showing retrieval operations of a second embodiment;  
     [0021]FIG. 11 illustrates a relation among, a map, location information, and direction information;  
     [0022]FIG. 12 is a flowchart showing operations for landmark retrieval;  
     [0023]FIG. 13 is a flowchart showing operations for self-formation of a guide page; and  
     [0024]FIG. 14 is a diagram showing a video camera of a fifth embodiment. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0025] Embodiments of the present invention will be hereinafter described in detail with reference to the accompanying drawings.  
     [0026] First Embodiment  
     [0027]FIG. 1 is a block diagram showing a structure of a recording and reproducing apparatus to which the present invention is applied. The recording and reproducing apparatus of FIG. 1 is a video camera having a function for recording a signal from an image pickup element such as a CCD on a disk medium.  
     [0028] In FIG. 1, a signal, which has passed through a lens  1  and has undergone photoelectrical conversion in a CCD  2 , is subjected to processing such as noise removal and gain adjustment in a pre-processing circuit  3  and is A/D converted in an AD converter  4 . Moreover, the signal is subjected to signal processing of an image pickup system such as aperture correction, gamma correction, and white balance in a camera signal processing circuit  5 . An output signal of the camera signal processing circuit  5  is converted into an analog signal in a D/A converter  11  to display an image being photographed on an attached monitor  12 . Simultaneously, an output of the D/A converter  11  can also be sent to an output terminal  13  to display the image on an external device.  
     [0029] In recording the image photoelectrically converted in the CCD  2 , the signal from the camera signal processing circuit  5  is once written in a buffer memory  10  through a data bus  18  and, subsequently, read out sequentially, and sent to a compression and expansion processing circuit  6  through the data bus  18  to have an information amount thereof compressed. The compressed image data is sent to a disk interface (I/F)  7  and is recorded on a disk  9  through the disk I/F  7 . A disk driver  8  controls a rotational operation of a disk motor.  
     [0030] In addition, an antenna  17  picks up a radio wave from a satellite (not shown) to receive location information such as latitude and longitude. The Global Positioning System (GPS) interface  16  converts the location information such as latitude and longitude received by the antenna  17  into a data format to be recorded on the disk  9  and sends the location information to the buffer memory  10  via the data bus  18 . The disk I/F  7  reads out the location information written in the buffer memory  10  at predetermined timing and records the location information on the disk  9  by multiplexing it with the image data.  
     [0031] A direction detector  19  detects, with a direction compass needle, etc., in which direction a video camera  100  is photographing. A direction detector interface  20  converts obtained direction information into a data format to be recorded on the disk  9  and writes the information in the buffer memory  10 . Thereafter, the disk I/F  7  reads out the direction information from the buffer memory  10  at predetermined timing and records the information on the disk  9  together with the image data.  
     [0032] In the case in which the data in the disk  9  is reproduced, the disk  9  is rotated by the disk driver  8  to reproduce the data from the disk  9  through the disk I/F  7 . The disk I/F  7  sends the reproduced data to the compression and expansion processing circuit  6  via the data bus  18  to expand the image data which was compressed at the time of recording in the compression and expansion processing circuit  6 . The expanded image data is stored in the buffer memory  10  and, then, sent to the camera signal processing circuit  5  via the data bus  18  and is subjected to blanking addition, color modulation, and the like, converted into an analog signal in the D/A converter  11 , and sent to an output terminal  13 , wile displaying a reproduced image on the attached monitor  12 .  
     [0033] At this point, in the case in which a size of the reproduced image is reduced, the image data stored in the buffer memory  10  after being expanded is reduced in size in a reduced image generator  21  to generate a reduced image such as a thumbnail image and, then, written in the buffer memory  10  again. Processing for displaying the reduced image generated at this point on the attached monitor  12  and recording it on the disk  9  is the same as the above-mentioned operations at the time of usual recording and reproduction.  
     [0034] In this embodiment, guide page data shown in FIG. 3 is recorded on the disk  9  in advance, and a photographed image shown in FIG. 2 is recorded therein later.  
     [0035]FIG. 2 is a diagram showing a file structure of photographed image data  200  to be recorded on the disk  9 .  
     [0036] The image data  200  consists of meta-data to be header, image data  202 , a plurality of thumbnail image data  203  to  205 , and meta-data  206  to be footer.  
     [0037] In this embodiment, image data is encoded by the MPEG system. In the MPEG system, the image data is encoded with a GOP basis, which GOP consists of a predetermined number of frames including an intra-frame encoded frame and a plurality of inter-frame encoded frames. Each GOP consists of a meta-data  207  and an image data part  208 . The image data part  208  consists of three types of encoding frames: an I frame which does not need a reference image other than itself; a P frame predicted in the forward direction from a preceding I or P frame; and a B frame predicted bi-directionally from I preceding and succeeding or P frames. Photographing time information  209 , the above-mentioned photographing position information  210 , and the like are stored in the meta-data  207 .  
     [0038] Although the number of the thumbnail image data  203  to  205  is equivalent to three frames for each file in FIG. 2, it is not limited to this. In addition, each of the thumbnail image data  203  to  205  is representative image data representing one frame of the image data  202 .  
     [0039]FIG. 3 is a diagram showing a file structure of a guide page  300  recorded on the disk  9 .  
     [0040] The guide page  300  consists of image data  302 , a plurality of thumbnail image data  303  and  304 , landmark data  305  in which sightseeing spots of various places, which can be a photographing object, are registered, a text  306  in which a legend concerning an image is written, and meta-data  307  to be footer.  
     [0041] It is assumed that the thumbnail  303  indicates an image  1  of a guide page shown in FIG. 4 and the thumbnail  304  indicates an image  2  of FIG. 4. Coordinates  310  at total eleven points representing areas  1  to  3  shown in FIG. 7 are stored in meta-data  308  of the thumbnail  303 . Image data  309  is recorded in association with the meta-data  308 . Coordinates  313  at four points representing an area  4  and four points representing an area  5  shown in FIG. 9 are stored in meta-data  311  of the thumbnail  304 . An image  312  is recorded in association with the meta-data  311 .  
     [0042] The landmark data  305  includes a plurality meta-data  317 , and each meta-data  317  consists of location information  318  representing a location of a landmark and name information  319  representing a name of the landmark. Link information  316  concerning the image  1  and the image  2  of FIG. 4 is stored in meta-data  314  of the text  306 , and the link information  316  specifies which image is to be displayed on which page on the text  306 . A text to be actually displayed is written in character information  315 . Although three thumbnail images are shown as an example in this embodiment, the number of thumbnail images is not limited to this. In addition, if an image in the image data  302  is designated as a link destination in the link information  316 , it is also possible to display a moving image on the image of FIG. 4. Further, the guide page is not limited to one page as shown in FIG. 4 but may extend across a plurality of pages.  
     [0043]FIG. 4 illustrates a display example of the guide page  300 . Here, the image  1  and the image  2  are displayed together with the legend. For example, in the case of a guide of New York, buildings in Manhattan are shown on the image  1  and the Statue of Liberty photographed from the Battery Park is shown on the image  2 , and the image  1  and the image  2  form guide images in conjunction with legends for them.  
     [0044]FIG. 7 shows a relation between a map and location information in the case in which the image  1  of FIG. 4 represents the buildings in Manhattan. In this embodiment, as location information representing locations in the entire Manhattan Island, the Manhattan Island  701  shown in FIG. 7 is divided into, for example, areas  1  to  3 , and four corners of the areas  1  to  3  are represented by illustrated coordinates, respectively, assuming that the top of FIG. 7 is the due north. If it is desired to represent the entire Manhattan Island more accurately, the respective areas only has to be divided into smaller areas.  
     [0045] As means for obtaining the guide page described above, a disk having the guide page recorded therein may be sold as a “travel guide disk”, or a guide page file stored in an external server may be downloaded using communication means such as the Internet.  
     [0046] In this embodiment, the video camera has a function of retrieving and reproducing the image data recorded on the disk  9  using the guide image shown in FIG. 4.  
     [0047] Next, processing in selecting an image in the guide image of FIG. 4 and reproducing the image will be described using a flowchart of FIG. 5. FIG. 5 is a flowchart showing operations of a CPU  14  in retrieval processing using a guide image. Further, in the processing of FIG. 5, the CPU  14  sequentially reproduces a large number of photographed image data recorded on the disk  9 , selects only a part of the. data relating to a designated image in a guide page, and reproduces the part.  
     [0048] First, when a user instructs reproduction of a guide page with an input key  15 , the CPU  14  reproduces data of the guide page recorded on the disk  9 . Then, the CPU  14  creates a guide page image shown in FIG. 4 based upon contents of information on this guide page and displays the guide page image on the monitor  12  (step S 501 ). Subsequently, the CPU  14  waits for the image  1  or the image  2  to be selected by the input key  15  (step S 502 ). When, for example, the image  1  is selected, the CPU  14  reads out location information  310  of the thumbnail  303  of FIG. 3 and calculates an area indicated by the image  1  (step S 503 ).  
     [0049] Next, the CPU  14  reads out the photographing position information  210  added to each GOP in the image data  202  in the photographed image data  200  of FIG. 2 recorded on the disk  9  (step S 504 ), and compares the location information  210  and the location information (area information)  310  of FIG. 3 (step S 505 ). If the location information  210  does not belong to any of the areas  1  to  3  of FIG. 7 designated by the location information  310 , the CPU  14  proceeds to step S 509  and judges whether or not the retrieval processing of location information has been completed for all the image data. If the location information  210  is included in any of the areas  1  to  3  of FIG. 7 designated by the location information  310 , the CPU  14  reproduces image data of a corresponding GOP (step S 506 ).  
     [0050] While the image data is being reproduced, the CPU  14  reproduces location information of each GOP sequentially (step S 507 ) and compares the reproduced location information with the location information  310  of FIG. 3 (step S 508 ). In this way, while the location information of the photographed image data  200  is included in any of the areas  1  to  3  of FIG. 7 designated by the location information  310 , the CPU  14  reproduces the image data according to the processing of steps S 7  to S 9 .  
     [0051] In case that the location information  210  of the photographed image data  200  is not included in any of the areas  1  to  3  designated by the location information  310 , the CPU  14  judges whether or not the retrieval processing of location information has been finished for all the image data recorded in the disk  9  (Step S 509 ). If the retrieval processing has not been finished for all the image data, the CPU  14  returns to step S 504 . When the processing for all the image data has been finished, the CPU  14  judges whether or not the user has instructed to stop the reproduction (step S 510 ). If instruction to stop the reproduction has not been given, the CPU  14  returns to step S 501  to reproduce the guide page  300  and comes into a state of waiting for selection of a guide image.  
     [0052] Next, comparison processing of steps S 505  and S 508  in FIG. 5 will be described using a flowchart of FIG. 6.  
     [0053] For example, if the image  1  of FIG. 4 is selected, since the respective coordinate points of FIG. 7 are recorded in the location information  310  of FIG. 3, the CPU  14  reads them out (step S 601 ). Next, the CPU  14  determines coordinates xt and yt of the location information  210  reproduced from the disk  9  (step S 602 ), compares the location information of the guide page and the location information of the photographed image to determine first whether or not the location information xt and yt of the photographed image are included in an area  1  of FIG. 7 (step S 603 ). If the location information  210  is included in the area  1 , the CPU  14  proceeds to step S 506  in order to start reproduction of a GOP corresponding to this location information.  
     [0054] If the location information  210  is not included in the area  1 , next, the CPU  14  judges whether or not the location information  210  is included in the area  2  (step S 604 ). If the location information  210  is included in the area  2 , the CPU  14  proceeds to step S 506 . If the location information  210  is not included in the area  2 , next, the CPU  14  judges whether or not the location information  210  is included in the area  3  (step S 605 ). If the location information  210  is included in the area  3 , the CPU  14  proceeds to step S 506 .  
     [0055] If the location information  210  is not included in the area  3  either, the CPU  14  proceeds to step S 509  in order to execute processing for the next GOP.  
     [0056] Note that, in this embodiment, an area is divided in a lattice shape and location information is judged as included in the area if the location information satisfies conditions on both the x axis and the y axis. However, a method of judgment is not limited to this. An area may be divided into triangles to judge whether or not location information is included in the area according to whether or not it is included in an area surrounded by linear functions.  
     [0057] As described above, in this embodiment, location information is added to a guide image on a guide page, in which explanations of each sightseeing spot are written, to be recorded on a disk in advance, and location information added to an image at the time of photographing and the location information of a selected guide image are compared to automatically reproduce the image. Thus, a user is capable of easily retrieving and reproducing a desired photographed image only by a simple operation of selecting a guide image.  
     [0058] More specifically, when the user displays the guide page of FIG. 4 and selects the image  1  on which the Manhattan Island is shown, an image recorded in Manhattan is automatically retrieved from among the image data recorded on the disk  9 , and reproduced. Thus, it is possible to instantaneously retrieve an image recorded in New York from a disk in which images obtained during travel all over the United States are recorded.  
     [0059] Note that, although photographing position information is added and recorded for each GOP of photographed image data in this embodiment, location information may be added for each photographed image file of FIG. 2. More specifically, the CPU  14  retrieves location information at the time when start of photographing is instructed and stores the location information in the buffer memory  10 . Then, the CPU  14  stores photographing position information in the file header (meta-data)  201  of FIG. 2 in response to the end of photographing and records the location information on the disk  9 .  
     [0060] In this embodiment, a series of moving images, which are recorded in a period from the instruction to start photographing until the instruction to end photographing, are recorded on the disk  9  as one file. Therefore, photographing position information is recorded for each file.  
     [0061] Further, retrieval processing using the photographing position information added for each file in this way will be described by referring to a flowchart of FIG. 8. FIG. 8 is a flowchart showing retrieval and reproduction processing performed by the CPU  14  using the photographing position information added for each file.  
     [0062] In FIG. 8, when instruction to reproduce a guide image is given, the CPU  14  reproduces the guide data of FIG. 3 from the disk  9  through the disk I/F  7  and writes the guide data in the buffer memory  10 . Then, the CPU  14  creates the guide image shown in FIG. 4 and displays it on the monitor  12  (step S 801 ). Next, the CPU  14  judges whether or not the guide image of FIG. 4 is selected (step S 802 ) and, if either of the guide images  1  and  2  is selected, the CPU  14  reads out from the memory  10  the location information  310  or  313  of the selected image  1  or  2  from the guide page data  300  of FIG. 3 (step S 803 ).  
     [0063] Next, the CPU  14  controls the disk I/F  7  to read out the header (meta-data)  201  of the plurality of file data  200  recorded on the disk  9 , respectively, and write it in the buffer memory  10  (step S 804 ), and compares the location information of the guide image and photographing position information of each file (step S 805 ). As a result, the CPU  14  detects photographing position information, which is included in an area designated by the location information of the guide image, from among the photographing position information of each file, and judges whether or not there are files within a range of the location information of the guide image (step S 806 ).  
     [0064] If there is data within the range, the CPU  14  controls the disk I/F  7  to sequentially reproduce the files within the range and display a reproduced image on the monitor  12  (step S 807 ) On the other hand, if a file within the range of the guide image is not recorded at all, the CPU  14  displays information indicative of that effect on the monitor  12  and proceeds to step S 809  (step S 808 ).  
     [0065] When the reproduction of image files is finished in step S 807 , the CPU  14  judges whether or not the user has instructed to stop the reproduction. If instruction to stop the reproduction has not been given, the CPU  14  returns to step S 802  and displays the guide screen of FIG. 4 on the monitor  12  to wait for selection of a guide image (step S 809 ).  
     [0066] In this way, even in the case in which photographing position information is added and recorded for each file, it becomes possible to display a guide page at the time of reproduction, retrieves an image file using location information of a guide image selected out of the guide page and the photographing position information for each file, and automatically reproduce the image file.  
     [0067] Second Embodiment  
     [0068] Next, operations in the case in which there are a plurality of location data of a guide image will be described. This embodiment is different from the first embodiment in that location data, which represents a plurality of areas apart from each other, is added to a guide image on a guide page.  
     [0069]FIG. 9 shows a relation between a map and location information in the case in which the image  2  of FIG. 4 shows the Statue of Liberty photographed from the Battery Park at the opposite bank.  
     [0070] Reference numeral  901  denotes the Liberty Island where the Statue of Liberty is set. The Liberty Island  901  is represented by coordinates shown in an area  4  in FIG. 9. On the other hand, reference numeral  902  denotes a part of Manhattan. The Battery Park, where a pier for ferry to the Liberty Island  901  is located, is represented by coordinates of an area  5 . As shown in FIG. 3, both the area  4  and the area  5  are recorded in the location information of the image  2 .  
     [0071] Operations for selecting an image, which has location information indicating a plurality of areas apart from each other, on the guide image of FIG. 4 to reproduce a recorded image will be described with reference to a flowchart shown in FIG. 10. Note that the same processing as in the flowchart of FIG. 5 is denoted by the identical reference symbol.  
     [0072] First, when a user instructs reproduction of a guide page with the input key  15 , the CPU  14  reproduces data of the guide page recorded on the disk  9 . Then, the CPU creates the guide page image shown in FIG. 4 based upon contents of this guide page information and displays it on the monitor  12  (step S 501 ). Subsequently, the CPU  14  waits for the image  1  or the image  2  to be selected by the input key  15  (step S 502 ). When, for example, the image  2  is selected, in order to urge the user to select the area  4  or the area  5  of FIG. 9, the CPU  14  displays information indicative of that effect on the monitor  12 . When the area  4  or the area  5  is selected by the user (step S 502 - 1 ), the CPU  14  reads out selected one of location information  313  recorded in the thumbnail  304  of FIG. 3 and calculates an area thereof (step S 503 ).  
     [0073] Next, the CPU  14  reads out the photographing position information  210  added for each GOP in the image data  202  in the photographed image data  200  of FIG. 2 recorded on the disk  9  (step S 504 ) and compares the location information  210  and the location information (area information)  310  of FIG. 3 (step S 505 ). If the location information  210  belongs to neither the area  4  nor the area  5  of FIG. 9 designated by the location information  310 , the CPU  14  proceeds to step S 509  and judges whether or not the retrieval processing of location information has been finished for all the image data. If the location information  210  is included in the area selected in step S 502 - 1  out of the areas  4  and  5  of FIG. 7 designated by the location information  310 , the CPU  14  reproduces image data of a corresponding GOP (step S 506 ).  
     [0074] While the image data is being reproduced, the CPU  14  reproduces sequentially location information of each GOP (step S 507 ) and compares the reproduced location information with the location information  310  of FIG. 3 (step S 508 ). In this way, while the location information of the photographed image data  200  is included in the selected area, the CPU  14  reproduces the image data according to the processing of steps S 7  to S 9 .  
     [0075] If the location information  210  of the photographed image data  200  is included in neither the area  4  nor the area  5  designated by the location information  310 , the CPU  14  judges whether or not the retrieval processing of location information has been finished for all the image data recorded in the disk  9  (Step S 509 ). If the retrieval processing has not been finished for all the image data, the CPU  14  returns to step S 504 . When the processing for all the image data has been finished, the CPU  14  judges whether or not the user has instructed to stop the reproduction (step S 510 ). If instruction to stop the reproduction has not been given, the CPU  14  returns to step S 501  to reproduce the guide page  300  and comes into a state of waiting for selection of a guide image.  
     [0076] In this embodiment, by adding location information representing a plurality of areas apart from each other to a guide image on a guide page, the CPU  14  can reproduce image data linking the image data to both an image photographed in a location of an object of the guide image and an image photographed by a user of a video camera in a location where the guide image was actually photographed by a guide page creator.  
     [0077] As a specific example, in the case in which the user selects the image  2  of FIG. 4 and selects the “Liberty Island” of the area  4  as location information, the video camera can automatically retrieve an image photographed in the Liberty Island where the Statue of Liberty as an object is located and reproduce an image of the Statue of Liberty in a near range.  
     [0078] In addition, in the case in which the user selects the “Battery Park” of the area  5  as location information, the video camera can automatically retrieve an image photographed in the Battery Park where the guide image creator photographed the Statue of Liberty and reproduce the image. At this point, if the user of the video camera has photographed an image of the “Statue of Liberty” at the same angle of view as the guide image, the video camera can instantaneously reproduce the image.  
     [0079] Third Embodiment  
     [0080] Next, an embodiment in which, as location information of a photographed image, location information automatically selected from the location information of landmarks described on the guide page  300  is recorded rather than location information itself from the GPSI/F  16  will be described.  
     [0081] In this embodiment, location information of sightseeing spots are registered in advance in the guide page area  300  of FIG. 3. A video camera detects that a user is photographing the registered sightseeing spot using not only a photographing position but also a photographing direction, and records the location information of the registered sightseeing spot as location information of the photographed image of FIG. 2.  
     [0082] Operations for, when the area  4  (the Statue of Liberty) is photographed from the area  5  (the Battery Park) of FIG. 9, recording location information of the area  4  in the meta-data  207  of the photographed image shown in FIG. 2 will be described with reference to FIGS. 11 and 12.  
     [0083] “The Statue of Liberty” is registered in advance in the landmark information of the guide page data  300  as a landmark, and coordinates (xc, yc) are recorded in the location information  318  indicating the location of the Statue of Liberty, and the “Statue of Liberty” is recorded in the name information  319 . In addition, it is assumed that landmarks  1101  (xa, ya) and  1102  (xb, yb) are registered in the landmark area  305  as other landmarks.  
     [0084]FIG. 12 is a flowchart showing detection and recording processing of location information performed by the CPU  14  at the time of moving image photographing by the video camera  100  of FIG. 1.  
     [0085] In FIG. 12, upon starting recording, the CPU  14  inputs photographing position information (xt, yt) shown in FIG. 11 through the GPSI/F  16  from the antenna  17  (step S 1201 ). Next, the CPU  14  inputs photographing direction information  0  from the direction detector  19  through the direction detector I/F  20  (step S 1202 ). Then, the CPU  14  uniquely calculates a straight line y=px+q shown in FIG. 11 based upon the photographing position information and the photographing direction information (step S 1203 ).  
     [0086] Next, the CPU  14  sequentially reads out the landmark data  305  of the guide page data from the disk  9  through the disk I/F  7  and judges whether or not a location of each landmark is near the straight line y=px+q (step S 1204 ).  
     [0087] For example, if the location information (xa, ya), (xb, yb), and (xc, yc) shown in FIG. 11 are registered in the landmark data  305 , the CPU  14  excludes the location information (xa, ya) because it is not near the straight line y=px+q.  
     [0088] As a result of comparing location information and the straight line for all the landmarks, the CPU  14  judges whether or not there is a landmark in a near location (step S 1205 ). Here, if a location of at least one land mark is near the straight line, the CPU  14  compares a value of the photographing position (xt, yt) and a value of the detected location information of the landmark to determine a final landmark to be a photographing object (step S 1206 ).  
     [0089] For example, in the case of the example of FIG. 11, when a photographing direction is taken into account, both values of the coordinate components x and y of the landmark to be a photographing object are smaller than the value of the photographing position (xt, yt). Since a value of the location (xb, yb) of the landmark  1102  is larger than the value of the photographing position (xt, yt), it can be seen that the landmark  1102  is near the straight line y=px+q but is not a photographing object.  
     [0090] In addition, since a value of the location (xc, yc) of the landmark  1103  is smaller than the value of the photographing position (xt, yt), the CPU  14  determines that the photographing object is the landmark  1103 .  
     [0091] When it is determined that the photographing object is the landmark  1103 , the CPU  14  records location information of the landmark as the photographing position information  210  (step S 1207 ). Note that, at this time, location information of a photographing point may be recorded together with location information of a landmark.  
     [0092] In addition, if it is judged that no landmark is near the straight line in step S 1205 , the CPU  14  records information of the photographing position inputted from the GPGI/F  16  as it is as the photographing position information  210  (step S 1208 ).  
     [0093] In this way, in this embodiment, location data of sightseeing spots is registered as landmarks in advance and a photographing direction of a video camera is measured. Consequently, in the case in which a famous sightseeing spot is photographed from a place apart from a photographing object, location information of the photographing object can be recorded as photographing position information instead of a location of the video camera.  
     [0094] In the case of the example shown in FIG. 11, if the Statue of Liberty (area  4 ) is photographed from the Battery Park (area  5 ), the location information (xc, yc) of the “Statue of Liberty” can be recorded as photographing position information instead of the location information of the area  5  where the video camera exists.  
     [0095] The retrieval processing described with reference to FIGS. 5 and 8 in the first embodiment is performed using the photographing position information recorded as described above. Consequently, for example, if the Statue of Liberty photographed from the Battery Park of the image  2  is selected on the guide image of FIG. 4, an image of the Statue of Liberty photographed from a distant place can be immediately reproduced. That is, regardless of a photographing point, an object which is the same as a selected guide image can be instantaneously retrieved and reproduced.  
     [0096] Fourth Embodiment  
     [0097] Next, an embodiment for automatically creating a guide page as shown in FIG. 4 using a photographed image will be described. FIG. 13 is a flowchart showing processing of the CPU  14  at the time when a guide page is created using the image data recorded in the disk  9  in the video camera  100  of FIG. 1.  
     [0098] When a user instructs creation (change) of a guide page with the input key  15 , the CPU  14  controls the disk I/F  7  to reproduce moving image data from the disk  9  and displays a moving image on the monitor  21  (step S 1301 ).  
     [0099] During reproduction of the moving image, the user pauses the reproduction at an image that the user wants to display as an image on the guide page of FIG. 4, and instructs the CPU  14  to generate a reduced image (step S 1302 ). Then, the CPU  14  writes an I frame in a GOP including a frame which was being reproduced at the time when the pause was instructed, and the meta-data  207  of the GOP in the buffer memory  10  and, at the same time, reduces the size of image data of selected one frame with the reduced image generator  21  (step S 1303 ). Then, the CPU  14  records the reduced image data in the thumbnail area of the guide page data  300  of the disk  9  together with the meta-data (step S 1304 ).  
     [0100] In this case, when the user inputs a text (step S 1305 ), the user inputs characters from the input key  15  to record the text in the character information  315  of a text area of the guide page data  300  (step S 1306 ). Next, the user uses the input key  15  to change a display layout or the like of the reduced image (step S 1307 ). After these operations, the CPU  14  ends the guide page formation.  
     [0101] In this way, a user generates a guide image from an image photographed by himself/herself, saves the guide image in a guide page together with location information thereof, and input a text to add a legend concerning the image. Consequently, even if the user cannot obtain a commercially available guide file or a guide file on a computer network, the user can form a guide page, and the simple retrieval of photographed image described in the first to third embodiments can be realized.  
     [0102] Fifth Embodiment  
     [0103] Next, processing in the case in which photographed image data and guide page data are recorded in different recording media will be described.  
     [0104]FIG. 14 is a diagram showing a structure of a video camera  100 ′ to which the present invention is applied.  
     [0105] In FIG. 14, components identical with those in the video camera  100  of FIG. 1 are denoted by the identical reference numerals and detailed description of the components will be omitted.  
     [0106] In FIG. 14, the guide page data  300  shown in FIG. 3 is recorded in a card  24  and, when the data is reproduced, clock is given to the card  24  by a card driver  23  to read out the data by a card I/F  22 . The photographed image data is recorded on the disk  9  in the same manner as the above-mentioned embodiments.  
     [0107] In this embodiment, the video camera operates in the same manner as described in the first to fourth embodiments except that photographed image data and guide page data are recorded in different recording media.  
     [0108] Note that, contrary to the above description, a photographed image may be recorded in the card  24  and a guide page is recorded on the disk  9 , or a disk, a disk driver and a disk interface circuit may be provided instead of the card  24 , the card driver  23  and the card interface circuit  22  and a photographed image and a guide page may be recorded on different disks.  
     [0109] In this embodiment, a guide page and a photographed image are recorded on separate media, whereby the guide page and the photographed image can be clearly distinguished from each other.  
     [0110] When image data is recorded on a recording medium, positioning data from positioning means is simultaneously recorded. The recording medium has external image data and external location information, which is recorded together with external image data, in advance. When the external image data is selected, image data including positioning data coinciding with the external location information is reproduced, whereby retrieval of image data relating to the external image data can be realized easily.  
     [0111] In addition, when image data is recorded on a recording medium, positioning data from positioning means is simultaneously recorded. A Reference image is generated from the image data recorded on the recording medium. The positioning data is recorded on the recording medium as reference image location data, and an article concerning the reference image is inputted and recorded on the recording medium. When the reference image is selected, image data including positioning data coinciding with the reference image location data is reproduced, whereby a reference image for facilitating retrieval of the image data can be created from the image data.  
     [0112] In addition, a recording medium has landmark position information. When image data is recorded on the recording medium, one of landmark position information is selected out of landmark position information and recorded as pseudo positioning data together with the image data. The recording medium has external image data and external location information, which is recorded together with the external image data, in advance. When the external image data is selected, image data including pseudo positioning data coinciding with the external location information is reproduced, whereby retrieval of image data, in which the same object as that of the external image data is recorded, can be easily realized regardless of a photographing position.  
     [0113] In addition, when image data is recorded on a first recording medium, positioning data from positioning means is simultaneously recorded. A second recording medium has external image data and external location information which is recorded together with external image data. When the external image data is selected, image data including positioning data coinciding with the external location information is reproduced, whereby distinction between the image data and the external image data necessary for realizing easy retrieval can be clarified.  
     [0114] Further, reference image, existing location information representing a location where an object of the reference image exists, photographing position information representing a location where the subject was photographed, and an article concerning the subject are recorded on a recording medium, whereby a guidebook can be displayed on a video camera or the like, and easy retrieval of a photographed image can be realized.  
     [0115] Many widely different embodiments of the present invention may be constructed without departing from the spirit and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments described in the specification, except as defined in the appended claims.