Patent Publication Number: US-2011058059-A1

Title: Object-Image Searching Apparatus

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     The disclosure of Japanese Patent Application No. 2009-206293, which was filed on Sep. 7, 2009, is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an object-image searching apparatus. More particularly, the present invention relates to an object-image searching apparatus which searches from an object scene image an object image that matches a registered object image. 
     2. Description of the Related Art 
     According to one example of this type of apparatus, a data-collection terminal device is installed at a customer service counter, and an analyzing section is installed at an information processing center. Both the data-collection terminal device and the analyzing section store a plurality of face images, as dictionary data, used for checking with a face image of a customer, and display a face image that resembles the face image of the customer, together with resemble-degree information, on a data display section. 
     However, the face images stored in the data-collection terminal device are limited to a proportion of high-importance face images selected from the face images stored in the analyzing section. As a result, the high-importance face images are searched at a high speed in the data-collection terminal device while a large amount of low-importance face images are searched in the analyzing section. 
     In the above-described device, the importance allocated to each of the face images follows instruction data inputted from an information input section. If the task of inputting the instruction data is troublesome, then a searching performance is deteriorated as a result. 
     SUMMARY OF THE INVENTION 
     An object-image searching apparatus according to the present invention, comprises: a fetcher which fetches an object scene image; a first searcher which searches an object image that matches a registered object image from the object scene image fetched by the fetcher; an acceptor which accepts a designating manipulation for designating the object image on the object scene image fetched by the fetcher; a second searcher which searches a predetermined object image that matches the object image designated by the designating manipulation from among a plurality of predetermined object images; and a definer which defines, as the registered object image, the predetermined object image discovered by the second searcher. 
     An object-image searching program product according to the present invention is an object-image searching program product executed by a processor of an object-image searching apparatus, comprises: a fetching step of fetching an object scene image; a first searching step of searching an object image that matches a registered object image from the object scene image fetched by said fetching step; an accepting step of accepting a designating manipulation for designating the object image on the object scene image fetched by said fetching step; a second searching step of searching for a predetermined object image that matches the object image designated by the designating manipulation from among a plurality of predetermined object images; and a defining step of defining, as the registered object image, the predetermined object image discovered by said second searching step. 
     An object-image searching method according to the present invention is an object-image searching method executed by an object-image searching apparatus, comprises: a fetching step of fetching an object scene image; a first searching step of searching an object image that matches a registered object image from the object scene image fetched by said fetching step; an accepting step of accepting a designating manipulation for designating the object image on the object scene image fetched by said fetching step; a second searching step of searching a predetermined object image that matches the object image designated by the designating manipulation from among a plurality of predetermined object images; and a defining step of defining, as the registered object image, the predetermined object image discovered by said second searching step. 
     The above described features and advantages of the present invention will become more apparent from the following detailed description of the embodiment when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram showing a basic configuration of one embodiment of the present invention; 
         FIG. 2  is a block diagram showing a configuration of one embodiment of the present invention; 
         FIG. 3  is an illustrative view showing one example of a state where an evaluation area is allocated to an imaging surface; 
         FIG. 4  is an illustrative view showing one example of a configuration of an extraction dictionary; 
         FIG. 5  is an illustrative view showing one example of a normal register referred to in face detecting behavior; 
         FIG. 6  is an illustrative view showing one example of a face-detection frame structure used for a face recognition process; 
         FIG. 7  is an illustrative view showing one portion of the face detecting behavior; 
         FIG. 8  is an illustrative view showing one example of an object scene captured by an imaging surface; 
         FIG. 9  is an illustrative view showing another example of the object scene captured by the imaging surface; 
         FIG. 10(A)  is an illustrative view showing one example of a reproduced image; 
         FIG. 10(B)  is an illustrative view showing one example of a reproduced image on which a zoom process and a scroll process are performed; 
         FIG. 11  is an illustrative view showing one example of a configuration of a general dictionary; 
         FIG. 12  is an illustrative view showing one example of a temporary register referred to in extraction-dictionary creating behavior; 
         FIG. 13  is an illustrative view showing another example of the configuration of the extraction dictionary; 
         FIG. 14  is an illustrative view showing still another example of the object scene captured by the imaging surface; 
         FIG. 15  is a flowchart showing one portion of behavior of a CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 16  is a flowchart showing another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 17  is a flowchart showing still another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 18  is a flowchart showing yet another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 19  is a flowchart showing another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 20  is a flowchart showing still another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; 
         FIG. 21  is a flowchart showing yet another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 ; and 
         FIG. 22  is a flowchart showing another portion of the behavior of the CPU applied to the embodiment in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIG. 1 , an object-image searching apparatus of one embodiment of the present invention is basically configured as follows: A fetcher  1  repeatedly fetches an object scene image. A first searcher  2  searches an object image that matches a registered object image from the object scene image fetched by the fetcher  1 . An acceptor  3  accepts a designating manipulation for designating the object image on the object scene image fetched by the fetcher  1 . A second searcher  4  searches a predetermined object image that matches the object image designated by the designating manipulation from among a plurality of predetermined object images. A definer  5  defines, as the registered object image, the predetermined object image discovered by the second searcher  4 . 
     Thus, when the object image on the object scene image is designated by the designating manipulation, the predetermined object image that matches the designated object image is searched from among the plurality of predetermined object images. The discovered predetermined object image is defined as the registered object image. The object image that matches this registered object image is thereafter searched from the object scene image. This improves a performance of searching a desired object image. 
     With reference to  FIG. 2 , a digital camera  10  according to this embodiment includes a focus lens  12  and an aperture unit  14  respectively driven by drivers  18   a  and  18   b . An optical image of an object scene that undergoes these components enters, with irradiation, an imaging surface of an imager  16 , and is subjected to a photoelectric conversion. Thereby, electric charges representing an object scene image are produced. 
     When a power source is applied, a CPU  26  determines a setting (i.e., an operation mode at a current time point) of a mode selector switch  28   md  arranged in a key input device  28 , under a main task. If the operation mode at a current time point is a camera mode, then an imaging task and a face detecting task are started up, and if the operation mode at the current time point is a reproduction mode, then a reproducing task is started up. 
     When the imaging task is started up, the CPU  26  commands a driver  18   c  to repeat exposure behavior and electric-charge reading-out behavior in order to start a moving-image fetching process. In response to a vertical synchronization signal Vsync periodically generated from a Signal Generator (SG) not shown, the driver  18   c  exposes the imaging surface and reads out the electric charges produced on the imaging surface in a raster scanning manner. From the imager  16 , raw image data based on the read-out electric charges is periodically outputted. 
     A pre-processing circuit  20  performs processes, such as digital clamp, pixel defect correction, and gain control, on the raw image data outputted from the imager  16 . The raw image data on which these processes are performed is written into a raw image area  32   a  of an SDRAM  32  through a memory control circuit  30 . 
     A post-processing circuit  34  reads out the raw image data accommodated in the raw image area  32   a  through the memory control circuit  30 , and performs processes such as a white balance adjustment, a color separation, and a YUV conversion, on the read-out raw image data. The YUV-formatted image data produced thereby is written into a YUV image area  32   b  of the SDRAM  32  through the memory control circuit  30 . 
     An LCD driver  36  repeatedly reads out the image data accommodated in the YUV image area  32   b  through the memory control circuit  30 , and drives an LCD monitor  38  based on the read-out image data. As a result, a real-time moving image (through image) of the object scene is displayed on a monitor screen. 
     With reference to  FIG. 3 , an evaluation area EVA is allocated to a center of the imaging surface. The evaluation area EVA is divided into 16 portions in each of a horizontal direction and a vertical direction; therefore, 256 divided areas form the evaluation area EVA. Moreover, in addition to the above-described processes, the pre-processing circuit  20  executes a simple RGB converting process for simply converting the raw image data into RGB data. 
     An AE evaluating circuit  22  integrates RGB data belonging to the evaluation area EVA, out of the RGB data produced by the pre-processing circuit  20 , at each generation of the vertical synchronization signal Vsync. Thereby, 256 integral values, i.e., 256 AE/AWB evaluation values, are outputted from the AE evaluating circuit  22  in response to the vertical synchronization signal Vsync. 
     Moreover, an AF evaluating circuit  24  extracts a high-frequency component of G data belonging to the same evaluation area EVA, out of the RGB data outputted from the pre-processing circuit  20 , and integrates the extracted high-frequency component at each generation of the vertical synchronization signal Vsync. Thereby, 256 integral values, i.e., 256 AF evaluation values, are outputted from the AF evaluating circuit  24  in response to the vertical synchronization signal Vsync. 
     The CPU  26  executes a simple AE process that is based on the output from the AE evaluating circuit  22 , in parallel with the moving-image fetching process, so as to calculate an appropriate EV value. An aperture amount and an exposure time period that define the calculated appropriate EV value are set to the drivers  18   b  and  18   c , respectively. As a result, a brightness of the through image is adjusted moderately. 
     When a shutter button  28   sh  is half-depressed, the CPU  26  executes the AE process based on the output of the AE evaluating circuit  22  so as to calculate an optimal EV value. Similarly to the above-described case, an aperture amount and an exposure time defining the calculated optimal EV value are set to the drivers  18   b  and  18   c , respectively. As a result, the brightness of the through image is adjusted strictly. Moreover, the CPU  26  executes an AF process that is based on the output from the AF evaluating circuit  24 . The focus lens  12  is set to a focal point by the driver  18   a , and thereby, a sharpness of the through image is improved. 
     When the shutter button  28   sh  is fully depressed, the CPU  26  starts up an I/F  40  for a recording process. The I/F  40  reads out one frame of image data representing an object scene that is obtained at a time point at which the shutter button  28   sh  is fully depressed, from the YUV image area  32   b  through the memory control circuit  30 , and records the read-out image data on a recording medium  42  in a file format. 
     Under the face detecting task executed in parallel with the imaging task, the CPU  26  repeatedly searches a face image of an animal from the image data accommodated in the YUV image area  32   b . For such a face detecting task, an extraction dictionary EXDC shown in  FIG. 4 , a normal register RGST 1  shown in  FIG. 5 , and a plurality of face-detection frame structures FD, FD, FD, . . . shown in  FIG. 6  are prepared. 
     According to  FIG. 4 , a characteristic of a face of an Egyptian Mau, which is one of the species of cats, is contained as a face pattern FP_ 1  in the extraction dictionary EXDC, and a characteristic of a face of an American Short Hair, which is another one of the species of cats, is contained as a face pattern FP_ 2  in the extraction dictionary EXDC. It is noted that in  FIG. 4 , English words of “Egyptian Mau” and those of “American Short Hair” are described. In reality, however, the characteristic of the face of the Egyptian Mau and that of the face of the American Short Hair are registered. 
     Furthermore, the normal register RGST 1  shown in  FIG. 5  is equivalent to a register used for describing the face-frame-structure information, and is formed by a column in which a position of the detected face image (a position of the face-detection frame structure FD at a time point at which the face image is detected) is described and a column in which a size of the detected face image (a size of the face-detection frame structure FD at a time point at which the face image is detected) is described. 
     Moreover, the face-detection frame structure FD shown in  FIG. 6  moves in a raster scanning manner on the YUV image area  32   b  corresponding to the evaluation area EVA shown in  FIG. 7  at each generation of the vertical synchronization signal Vsync. The size of the face-detection frame structure FD is reduced by a scale of “5” from “200” to “20” at each time that raster scanning is ended. 
     The CPU  26  reads out the image data belonging to the face-detection frame structure FD from the YUV image area  32   b  through the memory control circuit  30  so as to calculate a characteristic amount of the read-out image data. The calculated characteristic amount is checked with each of the face patterns FP_ 1  to FP_ 2  contained in the extraction dictionary EXDC. When a checking degree exceeds a threshold value TH, the position and the size of the face-detection frame structure FD at the current time point are registered, as face-frame-structure information, on the normal register RGST 1 . 
     When the raster scanning of the face-detection frame structure FD having a minimum size (=20) is ended, the CPU  26  detects the face-frame-structure information registered on the register RGST 1 , and issues a face-frame-structure character display command corresponding to the detected face-frame-structure information toward the LCD driver  36 . However, in a case where there is no face-frame-structure information on the register RGST 1 , the issuance of the face-frame-structure character display command is cancelled. The LCD driver  36  displays a face-frame-structure character KF 1  on the LCD monitor  38  by referring to the issued face-frame-structure character display command. 
     When an Egyptian Mau EM 1  shown in  FIG. 8  is captured on the imaging surface, the checking degree between the characteristic of the face image of the Egyptian Mau EM 1  and the face pattern FP 1  shown in  FIG. 4  exceeds the threshold value TH. As a result, the face-frame-structure character KF 1  is displayed at a position surrounding the face image of the Egyptian Mau EM 1 . In contrary, when a Siberian Husky SH 1  shown in  FIG. 9  is captured on the imaging surface, both checking degrees between the characteristic of the face image of the Siberian Husky SH 1  and each of the face patterns FP 1  and FP 2  shown in  FIG. 4  fall below the threshold value TH. At this time, the face-frame-structure character KF 1  is non-displayed. 
     When the face-frame-structure character KF 1  is displayed, the above-described AE process and AF process are executed by noticing the image within the face-frame-structure character KF 1 . On the other hand, when the face-frame-structure character KF 1  is non-displayed, the above-described AE process and AF process are executed by noticing the whole image of the evaluation area EVA. Thus, imaging parameters such as an exposure amount and a focus are satisfactorily adjusted. 
     When the reproducing task is started up, the CPU  26  designates the latest image file recorded on the recording medium  42 , as a reproduced-image file, and commands the I/F  40  and the LCD driver  36  to execute a reproducing process in which the designated image file is noticed. 
     The I/F  40  reads out the image data of the designated image file from the recording medium  42 , and writes the read-out image data into the YUV image area  32   b  of the SDRAM  32  through the memory control circuit  30 . 
     The LCD driver  36  reads out the image data accommodated in the YUV image area  32   b  through the memory control circuit  30 , and drives the LCD monitor  38  based on the read-out image data. As a result, a reproduced image based on the image data of the designated image file is displayed on the LCD monitor  38 . 
     Following such a reproducing process, the CPU  26  issues a registration-frame-structure character display command toward the LCD driver  36 . With reference to the applied registration-frame-structure character display command, the LCD driver  36  displays a registration frame structure character RF 1  at a center of the LCD monitor  38 . 
     Therefore, when the image data representing an object scene shown in  FIG. 9  is recorded on the recording medium  42  in the camera mode and this image data is reproduced from the recording medium  42  in the reproduction mode, the reproduced image and the registration frame structure character RF 1  are displayed on the LCD monitor  38  as shown in  FIG. 10(A) . 
     When a forward/rewind button  28   fr  of the key input device  28  is manipulated, the CPU  26  designates a succeeding image file or a preceding image file as the reproduced-image file. The designated-image file is subjected to a reproducing process similar to that described above. As a result, the reproduced image is updated. 
     When a tele/wide button  28   tw  of the key input device  28  is manipulated, the reproduced image displayed on the LCD monitor  38  is reduced or expanded. Thereby, a magnification of the displayed image is changed. When a cross button  28   cs  of the key input device  28  is manipulated, the reproduced image displayed on the LCD monitor  38  is scrolled. Thereby, a position of the displayed image is changed. 
     Therefore, if the tele/wide button  28   tw  and the cross button  28   cs  are manipulated in a state where a reproduced image shown in  FIG. 10(A)  is displayed, then the reproduced image is transitioned from  FIG. 10(A)  to  FIG. 10(B) , for example. 
     If a registration button  28   rg  of the key input device  28  is manipulated in a state where any one of the reproduced images is displayed, then in order to register one portion of the face patterns FP_ 1  to FP_ 70  contained in the general dictionary GLDC shown in  FIG. 11 , into the extraction dictionary EXDC, an extracting process is executed as follows. 
     In the general dictionary GLDC shown in  FIG. 11 , the face patterns FP_ 1  to FP_ 45  represent characteristics of faces of dogs of 45 species, respectively, the face patterns FP_ 46  to FP_ 60  represent characteristics of faces of cats of 15 species, respectively, and the face patterns FP_ 61  to FP_ 70  represent characteristics of faces of rabbits of 10 species, respectively. 
     In the extracting process, firstly, the image data belonging to the registration frame structure character RF 1  is read out from the YUV image area  32   b  through the memory control circuit  30 , and the characteristic amount of the read-out image data is calculated. The calculated characteristic amount is checked with each of the face patterns FP_ 0  to FP_ 70  contained in the general dictionary GLDC. An identification number of the face pattern of which the checking degree exceeds the threshold value TH, together with the checking degree, is registered on a temporary register RGST 2  shown in  FIG. 12 . 
     Thus, if checking degrees equal to or more than “2” are registered on the temporary register RGST 2 , then top two checking degrees are detected from the temporary register RGST 2 , and the face patterns corresponding to the detected checking degrees are duplicated from the general dictionary GLDC into the extraction dictionary EXDC. It is noted that if the number of the checking degrees registered on the temporary register RGST 2  is less than “2”, then an error process is executed. 
     Therefore, if the extracting process is executed in a display state shown in  FIG. 10(B) , the extraction dictionary EXDC is updated from the state shown in  FIG. 4  to a state shown in  FIG. 13 . According to  FIG. 13 , the characteristic of the face of the Siberian Husky, which is one of the species of the dogs, is contained in the extraction dictionary EXDC as the face pattern FP_ 1 , and the characteristic of a face of an Alaskan Malamute, which is another one of the species of the dogs, is contained in the extraction dictionary EXDC as the face pattern FP_ 2 . 
     If the Siberian Husky SH 1  is captured as shown in  FIG. 14  in the camera mode established after the extraction dictionary EXDC is thus updated, then the face-frame-structure character KF 1  is displayed at a position surrounding the face image of the Siberian Husky SH 1 . 
     The CPU  26  executes a plurality of tasks including the main task shown in  FIG. 15 , the imaging task shown in  FIG. 16 , the face detecting task shown in  FIG. 17  to  FIG. 19 , and the reproducing task shown in  FIG. 20  to  FIG. 22 , in a parallel manner. Control programs corresponding to these tasks are stored in a flash memory  44 . 
     With reference to  FIG. 15 , in a step S 1 , it is determined whether or not the operation mode at the current time point is the camera mode, and in a step S 3 , it is determined whether or not the operation mode at the current time point is the reproduction mode. When YES is determined in the step S 1 , the imaging task is started up in a step S 5  and the face detecting task is started up in a step S 7 . When YES is determined in the step S 3 , the reproducing task is started up in a step S 9 . When NO is determined in both the steps S 1  and S 3 , another process is executed in a step S 11 . Upon completion of the process in the step S 7 , S 9 , or S 11 , it is repeatedly determined in a step S 13  whether or not a mode switching manipulation is performed. When a determined result is updated from NO to YES, the task that is being started up is stopped in a step S 15 . Thereafter, the process returns to the step S 1 . 
     With reference to  FIG. 16 , in a step S 21 , the moving-image fetching process is executed. As a result, the through image representing the object scene is displayed on the LCD monitor  38 . In a step S 23 , it is determined whether or not the shutter button  28   sh  is half-depressed, and as long as a determined result is NO, a simple AE process in a step S 25  is repeated. As a result, the brightness of the through image is adjusted moderately. When YES is determined in the step S 23 , the AE process is executed in a step S 27  and the AF process is executed in a step S 29 . Thereby, the brightness and the focus of the through image are strictly adjusted. 
     In a step S 31 , it is determined whether or not the shutter button  28   sh  is fully depressed. In a step S 33 , it is determined whether or not the manipulation of the shutter button  28   sh  is canceled. When YES is determined in the step S 31 , the process advances to a step S 35  so as to execute the recording process, and then, the process returns to the step S 23 . When YES is determined in the step S 33 , the process directly returns to the step S 23 . As a result of the recording process in the step S 35 , the image data representing the object scene at the time point at which the shutter button  28   sh  is fully depressed is recorded on the recording medium  42  in a file format. 
     With reference to  FIG. 17 , in a step S 41 , it is determined whether or not the vertical synchronization signal Vsync is generated. When a determined result is updated from NO to YES, the size of the face-detection frame structure FD is set to “200” in a step S 43 , and the face-detection frame structure FD is placed at a starting position (upper left of the evaluation area EVA) in a step S 45 . In a step S 47 , one portion of the image data belonging to the face-detection frame structure FD is read out from the YUV image area  32   b , and the characteristic amount of the read-out image data is calculated. 
     In a step S 49 , a checking process for checking the calculated characteristic amount with each of the face patterns FP_ 1  and FP_ 2  contained in the extraction dictionary EXDC is executed. Upon completion of the checking process, it is determined in a step S 51  whether or not the face-detection frame structure FD reaches an ending position (lower right of the evaluation area EVA). 
     When a determined result is NO, in a step S 53 , the face-detection frame structure FD is moved in a raster direction by a predetermined amount, and thereafter, the process returns to the step S 47 . When a determined result is YES, it is determined in a step S 55  whether or not the size of the face-detection frame structure FD is reduced to “20”. When the determined result is NO, in a step S 57 , the size of the face-detection frame structure FD is reduced by “5”, and the face-detection frame structure FD is placed at a starting position in a step S 59 . Thereafter, the process returns to the step S 47 . 
     When a determined result in the step S 55  is YES, the process advances to a step S 61  so as to detect the face-frame-structure information described on the register RGST 1  and issue the face-frame-structure character display command corresponding to the detected face-frame-structure information toward the LCD driver  36 . However, in a case where there is no face-frame-structure information on the register RGST 1 , the issuance of the face-frame-structure character display command is cancelled. As a result, the face-frame-structure character KF 1  is displayed on the through image in an OSD manner. Upon completion of the process in the step S 61 , the process returns to the step S 41 . 
     The checking process in the step S 49  shown in  FIG. 18  is executed according to a subroutine shown in  FIG. 19 . Firstly, in a step S 71 , a variable L is set to “1”. In a step S 73 , the characteristic amount of the image data belonging to the face-detection frame structure FD is checked with the face pattern FP_L contained in the extraction dictionary EXDC. In a step S 75 , it is determined whether or not the checking degree exceeds the threshold value TH. 
     When the determined result is NO, the variable L is incremented in a step S 79 . In a step S 81 , it is determined whether or not the incremented variable L exceeds “2”. Then, when L≦2 is established, the process returns to the step S 73  while when L&gt;2 is established, the process is restored to a routine at an upper hierarchical level. When YES is determined in the step S 75 , the process advances to a step S 77  so as to describe the current position and the size of the face-detection frame structure FD, as the face-frame-structure information, on the register RGST 1 . Upon completion of the process in the step S 77 , the process is restored to the routine at the upper hierarchical level. 
     With reference to  FIG. 20 , in a step S 91 , the latest image file recorded on the recording medium  42  is designated, and in a step S 93 , the reproducing process in which the designated image file is noticed is executed. As a result, the reproduced image based on the image data accommodated in the designated image file is displayed on the LCD monitor  38 . In a step S 95 , the LCD driver  36  is commanded to display the registration-frame-structure character RF 1 . As a result, the registration-frame-structure character RF 1  is displayed on the through image in an OSD manner. 
     In a step S 97 , it is determined whether or not the forward/rewind button  28   fr  is manipulated. In a step S 103 , it is determined whether or not the tele/wide button  28   tw  is manipulated. Moreover, in a step S 107 , it is determined whether or not the cross button  28   cs  is manipulated, and in a step S 111 , it is determined whether or not the registration button  28   rg  is manipulated. 
     When a determined result in the step S 97  is YES, the process advances to a step S 99  so as to designate the succeeding image file or the preceding image file as a subsequent reproduced-image file. Upon completion of the process in the step S 99 , a reproducing process similar to that described above is executed in a step S 101 . Thereafter, the process returns to the step S 97 . 
     When a determined result in the step S 103  is YES, the process advances to a step S 105  so as to reduce or expand the reproduced image displayed on the LCD monitor  38 . Thereby, the magnification of the displayed image is changed. Upon completion of the reducing/expanding process, the process returns to the step S 97 . 
     When a determined result in the step S 107  is YES, the process advances to a step S 109  so as to scroll the reproduced image displayed on the LCD monitor  38 . Thereby, the position of the reproduced image to be displayed is changed. Upon completion of the scroll process, the process returns to the step S 97 . 
     When YES is determined in the step S 111 , the process advances to a step S 113  so as to execute the extracting process for registering one portion of the face patterns FP 1  to FP_ 70  contained in the general dictionary GLDC into the extraction dictionary EXDC. Upon completion of the extracting process, the process returns to the step S 97 . 
     The extracting process in the step S 113  is executed according to a subroutine shown in  FIG. 21 . In a step S 121 , one portion of the image data belonging to the registration-frame-structure character RF 1  is read out from the YUV image area  32   b , and the characteristic amount of the read-out image data is calculated. In a step S 123 , the variable L is set to “1”. In a step S 125 , the characteristic amount calculated in the step S 121  is checked with the face pattern FP_L contained in the general dictionary GLDC. 
     In a step S 127 , it is determined whether or not the checking degree exceeds the threshold value TH. When a determined result is NO, the process directly advances to a step S 131  while when the determined result is YES, the process advances to the step S 131  via a process in a step S 129 . In the step S 129 , the identification number L and the checking degree associated with each other are registered on the temporary register RGST 2 . 
     In the step S 131 , the variable L is incremented. In a step S 133 , it is determined whether or not the incremented variable L exceeds “70” equivalent to the number of the face patterns registered in the general dictionary GLDC. When a determined result is NO, the process returns to the step S 125 , and when the determined result is YES, the process advances to a step S 135 . 
     In the step S 135 , it is determined whether or not the number of the checking degrees registered on the temporary register RGST 2  is equal to or more than “2”. When a determined result is YES, the process advances to a step S 137  while when the determined result is NO, the process advances to a step S 139 . In the step S 137 , the two face patterns corresponding to the top two checking degrees are detected from the general dictionary GLDC, and the detected face patterns are registered in the extraction dictionary EXDC. In the step S 139 , the error process is executed. Upon completion of the process in the step S 137  or S 139 , the process is returned to a routine at an upper hierarchical level. 
     As can be seen from the above-described explanation, when the camera mode is selected, the CPU  26  fetches the object scene image captured by the imager  16  (S 21 ), and searches the object image that matches the face pattern (registered object image) contained in the extraction dictionary EXDC from the fetched object scene image (S 41  to S 61 ). When the reproduction mode is selected, the CPU  26  reproduces the object scene image recorded on the recording medium  42 , on the LCD monitor  38  (S 91  to S 101 ), and accepts the manipulations of the tele/wide button  28   tw , the cross button  28   cs , and the registration button  28   rg  as designating manipulation of the desired object image reproduced on the LCD monitor  38  (S 103  to S 111 ). The CPU  26  searches the face pattern that matches the object image designated by the designating manipulation from the plurality of face patterns (predetermined object images) contained in the general dictionary GLDC (S 121  to S 133 ), and contains the face pattern discovered thereby into the extraction dictionary EXDC (S 135  to S 139 ). 
     Thus, when the desired object image is designated by the designating manipulation, the face pattern that matches the designated object image is searched from among the plurality of face patterns contained in the general dictionary GLDC. The discovered face pattern is contained in the extraction dictionary EXDC, and after this time, the object image that matches this face pattern is searched from the object scene image. This improves a performance of searching the desired object image. 
     It is noted that in this embodiment, upon designation of the desired object image, the manipulations of the tele/wide button  28   tw , the cross button  28   cs , and the registration button  28   rg  are required. However, instead of these buttons being manipulated, touch manipulations on the monitor screen may be optionally required. Moreover, in this embodiment, the designating manipulation of the desired object image is accepted in the reproduction mode; however, the designating manipulation of the desired object image may also be optionally accepted in the camera mode. Furthermore, in this embodiment, a still camera which records a still image is assumed; however, it is possible to apply the present invention to a movie camera which records a moving image. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.