Patent Publication Number: US-2009225155-A1

Title: Celestial body observation device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2008-54691, filed Mar. 5, 2008, the entire contents of which are incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a celestial body observation device that provides various types of information to an observer during observations of a celestial body. 
     2. Description of the Related Art 
     Measuring the present position or accurate time by employing a GPS (Global Positioning System) is employed in many fields, for example, in car navigation. Because the present position can be measured, that is, positioned, with a GPS, a device has been suggested for displaying a star map that has to be visible from this position. 
     JP-A-2002-328624 suggests providing display means at an inner surface of a ceiling in an automobile cabin and displaying a star map including celestial bodies with a brightness equal to or higher than a predetermined brightness correspondingly to the present position of the vehicle and present time. 
     Further, JP-A-2003-316791 suggests a technology according to which a GPS device is installed on a cellular phone, a server sends celestial body information in the present position of the cellular phone to the cellular phone on the basis of the present position of the cellular phone, and the cellular phone displays the received information. 
     JP-A-2004-13066 discloses a feature of installing a geomagnetic sensor on a cellular phone and detecting the orientation of the cellular phone, thereby specifying a constellation that has to be positioned in this direction, and displaying the name of the constellation and the like on a display unit of the cellular device. 
     Within the framework of technology disclosed in all the aforementioned patent documents, information on celestial stars or constellations that will be possible to view in a present position is provided to an observer. Therefore, the observer has to perform an operation of comparing with the information displayed on a display screen of the cellular phone, while visually observing a celestial body. The resultant problem is that the comparison is sometimes difficult due to the state of the celestial body or a view line has to be moved between the sky and the screen to make the comparison and, therefore, specifying a celestial body positioned in the sky is not easy for the observer. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a celestial body observation device that allows an observer to verify easily information on a celestial body positioned in the sky. 
     The object of the present invention is attained by a celestial body observation device comprising: 
     a camera; 
     a database comprising a celestial body data file that stores celestial body data having a position of a celestial body and display information including a name of the celestial body; 
     celestial body comparison and determination means for comparing a pixel group having a constant luminance contained in image data picked up by the camera with celestial body data within the celestial body data file and specifying a celestial body corresponding to the pixel group; 
     image data generation means for acquiring display information of celestial body data relating to the celestial body associated with the pixel group from the celestial body data file on the basis of association between the pixel group specified by the celestial body comparison and determination means and the celestial body and generating complex image data in which the display information is superimposed on the image data; and 
     display means for displaying the complex image data. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram illustrating a configuration of a celestial body observation device of the first embodiment of the present invention; 
         FIG. 2  is a block diagram illustrating functions of the celestial body observation device of the first embodiment; 
         FIG. 3  is a flowchart illustrating an example of processing executed in the celestial body observation device of the present embodiment; 
         FIG. 4  is a flowchart illustrating an example of comparison processing with star map data relating to the present embodiment; 
         FIG. 5  illustrates an example of a preview image and star map data corresponding to a specified sky; 
         FIG. 6  illustrates an example of a preview image and an image in which a constellation name and constellation lines are superimposed on the preview image; 
         FIG. 7  illustrates another example of a preview image and an image in which a star name and constellation lines are superimposed on the preview image; 
         FIG. 8  is a block diagram illustrating functions of the celestial body observation device of the second embodiment; 
         FIG. 9  is a flowchart illustrating an example of comparison processing with star map data and planet data in the second embodiment; 
         FIG. 10  illustrates an example of a preview image and an image in which a planet name is superimposed on the preview image; and 
         FIG. 11  illustrates another example of a preview image and an image in which a planet name and a horoscope display are superimposed on the preview image. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will be described below with reference to the appended drawings.  FIG. 1  is a block diagram illustrating a configuration of a celestial body observation device of the first embodiment of the present invention. The celestial body observation device of the present embodiment is in the form of, for example, a digital camera. As shown in  FIG. 1 , the celestial body observation device has a CPU  11 , a camera  12 , a ROM  13 , a RAM  14 , a recording device  15 , various sensors  16 , a GPS device  17 , an input unit  18 , and a display unit  19 . In the present description celestial bodies include fixed stars and planets, and the fixed stars will be simply referred to as “stars”. 
     The CPU  11  controls pick-up with the camera  12 , zooming, etc. according to a program and also executes processing of various types such as acquisition of information relating to celestial bodies including fixed stars (stars) and planets in the sky according to the information from the sensors  16  or GPS  17 . The ROM  13  stores programs for realizing various functions of the celestial body observation device, for example, a camera control program, a program for actuating the GPS device and positioning, and a program for comparing image data picked up with the camera  12  and the below-described star map data. The RAM  14  stores a program that has been read from the ROM  13  and developed and data acquired in the processing process such as image data picked up by the camera  12 . 
     The recording device  15  is realized, for example, by a memory card or an USB memory and stores data of a below-described star-related DB  31  such as a star map data file  35  or image data picked up by the camera  12 . It goes without saying that the recording device  15  may be realized by a hard disk device. 
     The sensors  16  include an azimuth sensor and an angle sensor and can detect an orientation or an angle of the celestial body observation device (in particular, orientation and angle of elevation of a lens of the camera  12 ). The GPS  17  receives electromagnetic waves (GPS electromagnetic wave) from GPS satellites and determines the present position and also acquires accurate present time on the basis of trajectory information of a predetermined number of GPS satellites and time. The input unit  18  has an input key or a switch and allows an observer to input the desired information. The display unit  19  is provided, for example, with a liquid crystal display device and can display an image picked up by the camera  12  and the like. 
       FIG. 2  is a block diagram illustrating functions of the celestial body observation device of the first embodiment. As shown in  FIG. 2 , from the functional standpoint, the celestial body observation device of the present embodiment includes a camera unit  21 , an image processing unit  22 , a zoom control unit  23 , a field angle calculation unit  24 , a compression processing unit  25 , an image memory  26 , a clock  27 , a position detection unit  28 , an azimuth sensor  28 , and an elevation angle sensor  30 , a comparison and determination unit  31 , a relevant data extraction and processing unit  32 , the star-related database (DB)  33 , a display control unit  34 , and a display unit  19 . The camera unit  21  and zoom control unit  23  are realized by the camera  12 . The image processing unit  22 , field angle calculation unit  24 , compression processing unit  25 , comparison and determination unit  31 , relevant data extraction and processing unit  32 , and display control unit  34  are realized by the CPU  11 . The image memory  26  or star-related DB  33  is realized by the RAM  14  or recording device  15 . 
     The star-related DB  33  includes a star map data file  35  that includes information on a celestial body associated with position in the sky and time, a constellation data file  36  including information on celestial bodies constituting a constellation, and a galaxy data file  37  indicating a position of a galaxy in the sky. A star position that can be viewed on the sky differs depending on the observer&#39;s position (pick-up position) and time. Therefore, star map data of the star map data file  35  correspond to the present time (date and hour) and observer&#39;s position. 
     The image processing unit  22  implements processing necessary for image data provided by the camera unit  21  (for example, correction processing of color or the like and the below-described filtering processing). The zoom control unit  23  controls the lens of camera  21  correspondingly to the operation of a zoom switch contained in the input unit  18  by the observer. The field angle calculation unit  24  calculates a field angle of the lens of camera  21  controlled by the zoom control unit  23 . A range of the sky that has been picked up by the camera  21  is defined, as will be described hereinbelow, by calculations of the field angle. The compression processing unit  25  compresses the image data outputted from the image processing unit  22  according to a predetermined format and stores the compressed data in the image memory  26 . 
     The comparison and determination unit  31  specifies a celestial body included in the picked-up image on the basis of time information and position information from the GPS device  17 , information from the azimuth sensor  29  and elevation angle sensor  30 , field angle information from the field angle calculation unit  24 , and the star map data file  35  in the star-related DB  33 . The relevant data extraction and processing unit  32  reads necessary information relating to the specified celestial body from the star-related DB  33  correspondingly to the key operation of the input unit  18  by the user. 
       FIG. 3  is a flowchart illustrating an example of processing executed in the celestial body observation device of the present embodiment. In the present embodiment, the observer directs the lens of the camera  12  of the celestial body observation device in the desired direction and starts observations by operating the input unit  18  (for example, provides a preview instruction). 
     Where the preview instruction is received from the observer (step  301 ), the image processing unit  22  acquires image data from the camera unit  21  and outputs the acquired image data to the display control unit  34 . As a result, image data picked up by the lens of the camera unit  21  are displayed as a preview image on the screen of the display unit  19  (step  302 ). The observer can display an image of the desired field angle on the screen of the display unit  19  by operating a zoom switch (not shown in the figure) of the input unit  18 . In this case, the zoom control unit  23  controls the lens of the camera unit  21  correspondingly to the operation of the zoom switch performed by the observer. 
     For example, where the observer operates the switch of the input unit  18 , the image processing unit  22  executes filtering processing of image data of the preview image (step  303 ). In the filtering processing, the image data are so processed that only pixels with a luminance equal to or higher than a predetermined luminance are left. As a result, only a series of pixel group corresponding to stars with a class equal to or higher than a predetermine class (for example, class 6) are present in the image data. Furthermore, adjacent pixel groups having a fixed luminance are recognized as stars, the recognized pixel groups are associated with the position and luminance thereof, and the association is stored in the RAM  14 . As a result, the position and luminance of the pixel group recognized as a star in the image data are defined. 
     Then, the comparison and determination unit  31  executes a processing of comparing the pixel group recognized as the star with the star map data of the star map data file  35  of the star-related DB  33  (step  304 ).  FIG. 4  is a flowchart illustrating an example of a processing of comparing with star map data relating to the present embodiment. As shown in  FIG. 4 , the comparison and determination unit  31  executes positioning with respect to the GPS device  17 , acquires a present time (step  401 ), and also acquires the present position (longitude, latitude) (step  402 ). Actually the GPS device  17  receives GPS electromagnetic waves from two GPS satellites in a two-dimensional mode and from four GPS satellites in a three-dimensional mode and obtains the present time and the present position. 
     The comparison and determination unit  31  acquires the azimuth of the lens of the camera unit  21  on the basis of information from the azimuth sensor  29  (step  403 ) and also acquires the elevation angle of the lens on the basis of information from the elevation angle sensor  30  (step  404 ). Furthermore, the comparison and determination unit  31  acquires the field angle of the lens of the camera unit  21  from the field angle calculation unit  24  (step  405 ). A sky range corresponding to the preview image is specified by the azimuth (azimuth angle) of the lens, elevation angle of the lens, and field angle of the lens (step  406 ). 
     Then, the comparison and determination unit  31  acquires star map data relating to the stars contained in the specified sky range from the star map data file  35  (step  407 ). The comparison and determination unit  31  selects a certain pixel group from among the pixel groups corresponding to stars in the image data subjected to filtering processing and compares the selected pixel group with star map data relating to stars positioned in the specified sky range (step  408 ). In this comparison, for example, a luminance of the pixel group corresponding to a star is compared with a luminance of star map data of the star that is a comparison object, a position of a pixel group adjacent to the aforementioned pixel group is compared with a position of a star adjacent to the star that is a comparison object, and a luminance of the adjacent pixel group is compared with a luminance of the adjacent star. Where the luminance of the pixel group corresponding to the star is almost identical to the luminance of star map data relating to the star that is a comparison object (the difference is within a fixed range), the position of the pixel group adjacent to the aforementioned pixel group is almost identical to the position of the star adjacent to the star that is a comparison object (the difference is within a fixed range), and a luminance of the adjacent pixel group is almost identical to the luminance of the adjacent star (the difference is within a fixed range), the pixel group corresponding to a star can be determined to be identical to the star that is a comparison object. Furthermore, by expanding the range of adjacent pixel groups and studying the match of position and luminance with the star map data relating to other stars, it is possible to associate successively the respective pixel groups with stars. 
     The comparison of pixel groups with stars in step  408  is not limited to the above-described comparison. For example, a configuration may be employed in which matching is executed between the pixels constituting image data of the preview image and pixels constituting image data obtained by developing the star map data corresponding to the above-described range of sky, calculating a sum total of correlation values, for example, shifting the image data of the preview image, repeating the matching, specifying the matching operation with the largest sum total of correlation values, and obtaining the correspondence of pixel group and star of this operation. 
     The comparison and determination unit  31  determines whether correspondence was established between a pixel group in the preview image and a star (step  409 ). If the determination result of step  409  is No, star map data relating to the next star are selected in the star map data file  35  (step  410 ) and comparison is performed between the pixel group corresponding to the star in the preview image and the star map data of the selected star (step  408 ). If the determination result of step  409  is Yes, data including the association between each pixel group corresponding to a star in the preview image and the star map data are stored in the RAM  14  (step  411 ). 
       FIG. 5  illustrates an example of a preview image and star map data corresponding to specified sky. Actual data indicate the position or luminance of a pixel group (star), but in  FIG. 5 , the data are shown as a visualized state in the sky. As a result of processing shown in  FIG. 4 , a correspondence is established between a pixel group of a predetermined luminance in a preview image  500  and a star indicated by star map data  510 . In  FIG. 5A , for example, pixel groups  501 - 504  in the preview image  500  respectively correspond to stars  511 - 514  indicated by star map data in  FIG. 5B . The star map data include necessary information such as star name and class. Further, information relating to a constellation to which the star belongs is included in the constellation data file  36 . Therefore, the above-described comparison processing can specify the name of the star associated with the pixel group in the preview image or the name of the constellation to which this star belongs. 
     The relevant data extraction and processing unit  32  acquires display setting information inputted by the observer operating the input key of the input unit  18  (step  305 ). In the present embodiment, the display setting information includes, for example, such items as “a constellation line”, “a constellation name”, “a star name”, and “a galaxy—star cluster name”, and the observer can select one or more of these items by operating the input key. The display control unit  34  acquires the relevant data from the star-related DB  33  correspondingly to the items contained in the display setting information (step  306 ). Then, image data are generated in which the display based on the data acquired from the star-related DB  33  is superimposed on the preview image (step  307 ). The image data are transferred to the display unit  19  (step  308 ). As a result, an image having added thereto the display setting information selected by the observer is displayed on the screen of the display unit  19 . 
     For example, when the display setting information includes “a constellation line” and “a constellation name”, the relevant data extraction and processing unit  32  specifies stars included in the preview image with reference to the star map data in the star map data file  35  and reads the name of the constellation to which each star belongs and data on the constellation lines that connect the stars from the constellation data file  36 . The display control unit  34  then generates image data onto which displays of the constellation name and constellation lines are superimposed. 
       FIG. 6  illustrates an example of a preview image and an image in which a constellation name and constellation lines are superimposed on the preview image. A preview image  500  in  FIG. 6A  is identical to that shown in  FIG. 5A . In an image  600  shown in  FIG. 6B , a constellation name (see reference numeral  601 ) and constellation lines (for example, see reference numerals  611  and  612 ) are superimposed on the preview image.  FIG. 7  illustrates another example of a preview image and an image in which a star name and constellation lines are superimposed on the preview image. A preview image  500  in  FIG. 7A  is identical to that shown in  FIG. 5A . In an image  700  shown in  FIG. 7B , star names (see reference numerals  701  and  702 ) and constellation lines are superimposed on the preview image. 
     Preview image data or image data having added thereto the display setting information selected by the observer are stored in the image memory  26  in response to the key operation of the input unit  18  by the observer. 
     When it is determined that a galaxy is contained in the preview image, that is, when the comparison processing determines that a pixel group in the preview image corresponds to a galaxy, an image is generated in which the display of the galaxy name acquired from the galaxy data file  37  is superimposed on the preview image, and the generated image is displayed on the screen of the display unit  19 . 
     With the present embodiment, a celestial body is associated with a pixel group in image data on the basis of image data acquired by the camera, and display setting information of the celestial body associated with the pixel group, for example, the display of a star name is displayed in superposition on the image data. Therefore, information relating to stars that are presently seen can be acquired by referring to the image displayed on the screen of the display unit, without actually viewing the sky (it is not necessary to move a line of view). 
     Further, with the present embodiment, the image data pick-up date and hour can be measured. Therefore, it is possible to restrict the star map data from the star map data file to those of a star that can be picked up at the relevant pick-up date and hour and can be contained in the image data. In addition, with the present embodiment, the pick-up position of pick-up data is measured. Therefore, it is possible to restrict the star map data to those that can be picked up from the pick-up position and can be contained in the image data. As a result, a load on the comparison processing that associates a pixel group in the image data with a star can be reduced and the comparison processing can be implemented within a short interval. 
     Furthermore, with the present embodiment, the orientation and elevation angle of the lens of the camera unit are detected. As a result, a sky portion onto which the camera lens is directed can be specified and celestial body data serving as an object of comparison with the pixel group can be restricted to the celestial body data relating to the celestial body included in the aforementioned sky portion. 
     Furthermore, by calculating the field angle of the lens of the camera unit, it is possible to specify almost perfectly a sky portion contained in the image data. As a result, a load on the comparison processing that associates a pixel group in the image data with a star can be reduced and the comparison processing can be implemented within a short interval. 
     Furthermore, in the present embodiment, a constellation data file that stores constellation data having constellation names, celestial bodies constituting the constellations, and constellation lines connecting the celestial bodies is provided, and the display of the constellation names and constellation lines is superimposed on the image data. Therefore, the constellations, rather than only the star names, can be known without actually looking at the sky (in order words, without moving the line of view). 
     The second embodiment of the present invention will be described below. In the first embodiment, a star name or constellation is specified with reference to the star-related DB 33  storing star map data file  35 , constellation data file  36 , and galaxy data file  37 , and an image onto which the display indicating the star name and constellation is superimposed is provided to the observer. In the second embodiment, a planet-related database  40  storing various data relating to planets is additionally provided and an image having superimposed thereon information relating to planets can be provided to the observer.  FIG. 8  is a block diagram illustrating functions of the celestial body observation device of the second embodiment. In  FIG. 8 , structural components identical to those of the celestial body observation device of the first embodiment shown in  FIG. 2  are assigned with identical reference numerals. The celestial body observation device of the second embodiment comprises the planet-related database (DB)  40  in addition to the structural components of the celestial body observation device of the first embodiment. 
     The planet-related DB  40  includes a planet data file  41  including information on planets associated with a position in the sky and date-hour and a horoscope data file  42  including information on a horoscope associated with planets and date-time. 
     In the celestial body observation device of the second embodiment, processing is also executed according to flowchart shown in  FIG. 3 . Thus, where a preview instruction is received from the observer (step  301 ), the image processing unit  22  acquires image data from the camera unit  21  and outputs the acquired image data to the display control unit  34 . As a result, image data picked up by the lens of the camera unit  21  are displayed as a preview image on the screen of the display unit  19  (step  302 ). The observer can display an image of the desired field angle on the screen of the display unit  19  by operating a zoom switch (not shown in the figure) of the input unit  18 . In this case, the zoom control unit  23  controls the lens of the camera unit  21  correspondingly to the operation of the zoom switch performed by the observer. The image processing unit  22  executes filtering processing of image data of the preview image (step  303 ). The filtering processing verifies the position and brightness (luminance) of pixel groups recognized as stars in the image date. The comparison and determination unit  31  executes a processing of comparing the pixel group recognized as the star with the star map data within the star map data file  35  of the star-related DB  33  and planet data within the planet data file  41  of the planet-related DB  40  (step  304 ). 
       FIG. 9  is a flowchart illustrating an example of comparison processing with star map data and planet data in the second embodiment. Step  901  to step  906  in  FIG. 9  are identical to steps  401 - 406  in  FIG. 4 . In other words, the comparison and determination unit  31  specifies a sky-range corresponding to the preview image by the present time, present position, and azimuth, elevation angle, and field angle of the lens of the camera  21  obtained in steps  901 - 905 . 
     Then, the comparison and determination unit  31  acquires star map data corresponding to the specified sky range from the star map data file  35  and acquires planet data corresponding to the sky range from the planet data file  41  (step  907 ). The comparison and determination unit  31  generates composite data in which the star map data and planet data overlap (step  908 ). The composite data include positions and luminance of stars and positions and luminance of planets. Therefore, the comparison and determination unit  31  selects a certain pixel group from among pixel groups corresponding to stars in the image data subjected to filtering processing and compares the selected pixel group with the star map data or planet data indicated in the composite data corresponding to the specified sky range (step  909 ). The comparison in step  909  is identical to the comparison in step  408  of the first embodiment. 
     The comparison and determination unit  31  determines whether correspondence has been established between a pixel group in the preview image and a star or a planet in the composite data (step  910 ). If the determination result of step  910  is No, next star data or planet data are selected in the composite data (step  911 ), and comparison is performed between the pixel group corresponding to the star in the preview image and the star map data or planet data (step  909 ). If the determination result of step  910  is Yes, data including the association between each pixel group corresponding to a star in the preview image and the star map data or planet data are stored in the RAM  14  (step  912 ). 
     The relevant data extraction and processing unit  32  acquires display setting information inputted by the observer operating the input key of the input unit  18  (step  305 ). In the second embodiment, the display setting information includes, for example, such items as “a planet name”, “a horoscope ”, and “a distance to the planet” in addition to “a constellation line”, “a constellation name”, “a star name”, and “a galaxy—star cluster name”, and the observer can select one or more of these items by operating the input key of the input unit  18 . 
     The display control unit  34  acquires the relevant data from the star-related DB  33  or planet-related DB  40  correspondingly to the items contained in the display setting information (step  306 ). Then, image data are generated in which the display based on the data acquired from the star-related DB  33  or planet-related DB  40  is superimposed on the preview image (step  307 ). The image data are transferred to the display unit  19  (step  308 ). As a result, an image having added thereto the display setting information selected by the observer is displayed on the screen of the display unit  19 . 
       FIG. 10  illustrates an example of a preview image and an image in which a planet name is superimposed on the preview image. In the example shown in  FIG. 10 , “a planet name” is selected as the display setting information. Therefore, the relevant data extraction and processing unit  32  reads the name of the planet contained in the preview image with reference to the planet data in the planet data file  41 , and the display control unit  34  generates image data onto which the planet name display is superimposed. In the preview image  1000  shown in  FIG. 10A , only a pixel group corresponding to stars or planets is displayed, but in an image  1010  shown in  FIG. 10B , the planet name (see reference numeral  1011 ) is superimposed on the preview image. 
       FIG. 11  illustrates another example of a preview image and an image in which a planet name and a horoscope display are superimposed on the preview image. The preview image in  FIG. 11A  is identical to that shown in  FIG. 1A . In the example shown in  FIG. 11 , “a planet name” and “horoscope” are selected as display setting information. Therefore, the extraction and processing unit  32  reads the name of the planet included in the preview image with reference to the planet data contained in the planet data file  41  and also reads the horoscope data associated with the planet and the present time (date and hour) in the horoscope data file  42 , and the display control unit  34  generates image data onto which the planet name and horoscope display is superimposed. In the image  1100  shown in  FIG. 11   b , the planet name and horoscope (see reference numeral  1101 ) are superimposed on the preview image. 
     In the second embodiment, the preview image data or image data having added thereto display setting information selected by the observer are also stored in the image memory  26  by the key operation of the input unit  18  performed by the observer. 
     When the display setting information is “a distance to the planet”, the relevant data extraction and processing unit  32  acquires the distance to the planet contained in the preview image with reference to the planet data contained in the planet data file  41 , and the display control unit  34  generates image data onto which the display of the distance to the planet is superimposed. 
     With the second embodiment, pixel groups in the image are associated with planets on the basis of image data acquired by the camera, and information of various kinds (horoscope, distance to the planet, and the like) relating to the planet is displayed with superposition on the image data. Therefore, information relating to stars that are presently seen can be acquired by the observer by referring to the image displayed on the screen of the display unit, without actually viewing the sky (it is not necessary to move a line of view). 
     Furthermore, in the second embodiment, a planet data file that stores planet data having planet names, horoscope information relating to planets, and distance between the planets is provided, and the display of the planet names is superimposed on the image data. Therefore, the planet name and other information relating to the planet can be known without actually looking at the sky (in order words, without moving the line of view). 
     The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims. It goes without saying that these modifications are also included in the scope of the present invention.