TECHNICAL FIELD [0001] The present invention relates to an information processing device, more specifically, relates to an information processing device that further outputs a result through the use of the results of recognition by a plurality of recognition engines. BACKGROUND ART [0002J In accordance with development of information processing tecliniques, various recognition engines executing recognition processes have been developed. For example, there exist various recognition engines, such as a recognition engine that identifies a person from still image data, a recognition engine that generates location information tracing the flow of a person from moving image data, and a recognition engine that generates text data from speech data. As one example, Patent Document 1 discloses a robot that is equipped with recognizers for image recognition and speech recognition. [0003] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-283959 Although various recognition engines have been developed as described above, the respective recognition engines are incorporated in specific systems depending on individual applications, and therefore, it is difficult to use these recognition engines for other purposes. Even if it is intended to reuse the recognition engines, development of a new system capable of using the recognition engines needs huge cost because output formats of the recognition engines are different from each other. Thus, there is a problem that it is impossible to flexibly respond to an application's request for use of output results acquired from a plurality of recognition engines and development of such a system needs huge cost. SUMMARY [0005] Accordingly, an object of the present invention is to solve the abovementioned problem; it is difficult to reuse output results acquired from a plurality of recognition engines at low cost. [00061 In order to achieve the abovementioned object, an information processing device of an exemplary embodiment of the present invention includes: a recognition result acquiring means for acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data; and an integration recognition result outputting means for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, wherein: the recognition result acquiring means is configured to acquire the respective recognition result information in a data format common to the plurality of recognition engines, from the plurality of recognition engines; and the integration recognition result outputting means is configured to integrate the respective recognition result information based on the respective recognition result information and output as the new recognition result. [0007] Further, a computer program of another exemplary embodiment of the present invention is a computer program including instructions for causing an information processing device to realize: a recognition result acquiring means for acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data; and an integration recognition result outputting means for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, the computer program also including instructions for: causing the recognition result acquiring means to acquire the recognition result information in a data format common to the plurality of recognition engines, from each of the plurality of recognition engines; and causing the integration recognition result outputting means to integrate the respective recognition result information based on the respective recognition result information and output as the new recognition result. [0008] Further, an information processing method of another exemplary embodiment of the present invention includes: acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data, the respective recognition result information being in a data formal common to the plurality of recognition engines; and integrating the respective recognition result information based on the respective recognition result information acquired from the plurality of recognition engines and outputting as a new recognition result. [0009] With the configurations as described above, the present invention can provide an information processing device capable of reusing outputs results acquired from a plurality of recognition engines at low cost. BRIEF DESCRIPTION OF DRAWINGS [0010] Fig. 1 is a block diagram showing the configuration of an intermediate-layer device in the present invention; Fig. 2 is a diagram showing an example of the structure of a recognition result registered in an intermediate-layer device in a first exemplary embodiment of the present invention; Fig. 3 is a diagram showing an example of the structure of a recognition result registered in the intermediate-layer device in the first exemplary embodiment of the present invention; Fig. 4 is a diagram showing an example of the structure of a recognition result registered in the intermediate-layer device in the first exemplary embodiment of the present invention; Fig. 5 is a flowchart showing the operation of the intermediate-layer device in the first exemplary embodiment of the present invention; Fig. 6 is a diagram showing an example of a recognition result acquired from a recognition engine by the intermediate-layer device in the first exemplary embodiment of the present invention; Fig. 7 is a diagram showing an example of a recognition result acquired from the recognition engine by the intermediate-layer device in the first exemplary embodiment of the present invention; Fig. 8 is a diagram showing a state in which the intermediate-layer device is integrating recognition results acquired from recognition engines in the first exemplary embodiment of the present invention; Fig. 9 is a diagram showing a state in which the intermediate-layer device has integrated recognition results acquired from the recognition engines in the first exemplary embodiment of the present invention; Fig. 10 is a diagram showing an example of the structure of a recognition result registered in an intermediate-layer device in the second exemplary embodiment of the present invention; Fig. 11 is a diagram showing an example of the structure of a recognition result registered in the intermediate-layer device in the second exemplary embodiment of the present invention; Fig. 12 is a diagram showing a state in which the intermediate-layer device is integrating recognition results acquired from recognition engines in the second exemplary embodiment of the present invention; Fig. 13 is a diagram showing a state in which the intermediate-layer device has integrated recognition results acquired from the recognition engines in the second exemplary embodiment of the present invention; and Fig. 14 is a block diagram showing the configuration of an information processing device in Supplementary Note 1 of the present invention. EXEMPLARY EMBODIMENTS [0011] The whole or part of the exemplary embodiments disclosed above can be described as the following supplementary notes. Below, the outline of the configuration of the information processing device according to the present invention will be described with reference to Fig. 14. However, the present invention is not limited to the following configurations. [0057] (Supplementary Note 1) An information processing device 200 comprising: a recognition result acquiring means 201 for acquiring respective recognition result information outputted by a plurality of recognition engines 211, 212 and 213 executing different recognition processes on recognition target data; and an integration recognition result outputting means 202 for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, wherein: the recognition result acquiring means 201 is configured to acquire the respective recognition result information in a data format common to the plurality of recognition engines, from the plurality of recognition engines; and the integration recognition result outputting means 202 is configured to integrate the respective recognition result information based on the respective recognition result information, and output as the new recognition result. [0058] (Supplementary Note 2) The information processing device according to Supplementary Note 1, wherein the integration recognition result outputting means is configured to, when the respective recognition result information include information that correspond to each other in accordance with a predetermined standard, integrate the respective recognition result information and output as the new recognition result. [0059] (Supplementary Note 3) The information processing device according to Supplementary Note 1 or 2, comprising a definition information storing means for storing: recognition result definition information that defines a data format of the recognition result information acquired by the recognition result acquiring means from each of the plurality of recognition engines; and integration definition information that defines an integration format in which the integration recognition result oulputting means integrates the respective recognition result information, wherein: the recognition result acquiring means is configured to acquire the respective recognition result information in the data format defined by the recognition result definition infonnation; and the integration recognition result outputting means is configured to integrate the respective recognition result information in the integration format defined by the integration definition information, and output the new recognition result [0060] (Supplementary Note 4) The information processing device according to any of Supplementary Notes 1 to 3, wherein the recognition result infonnation acquired by the recognition result acquiring means from each of the plurality of recognition engines is in a graph-structured or tree-structured data format [0061] (Supplementary Note 5) The information processing device according to Supplementary Note 2, wherein: the recognition result acquiring means is configured to acquire the recognition result information from an object recognition engine that recognizes an object from the recognition target data and a flow recognition engine that recognizes a flow representing a trajectory of a predetermined object from the recognition target data, respectively; and the integration recognition result outputting means is configured to integrate by relating flow information of a predetermined object with object information and output as the new recognition result, the flow information being the recognition result information acquired from the flow recognition engine, and the object information being the recognition result information acquired from the object recognition engine. [0062] (Supplementary Note 6) The information processing device according to Supplementary Note 5, wherein: the recognition result acquiring means is configured to: acquire the recognition result information including location information representing a position of an object recognized from the recognition target data by the object recognition engine and also representing a date and time when the object is recognized, from the object recognition engine; and also acquire flow information of a predetermined object recognized from the recognition target data by the flow recognition engine, from the flow recognition engine; and the integration recognition result acquiring means is configured to, when the flow information acquired from the flow recognition engine includes information that corresponds to the location information acquired from the object recognition engine in accordance with a predetermined standard, integrate by relating the flow information that is the recognition result acquired from the flow recognition engine with object information identified by the recognition result information that is acquired from the object recognition engine and that includes the information corresponding to the location information, and output as the new recognition result. [0063] (Supplementary Note 7) The information processing device according to Supplementary Note 2, wherein: the recognition result acquiring means is configured to acquire the recognition result information from a plurality of object recognition engines recognizing an object from the recognition target data in different recognition processes, respectively; and the integration recognition result outputting means is configured to integrate by identifying one object information based on respective object information that arc the respective recognition result information acquired from the plurality of object recognition engines, and output the new recognition result. [0064] (Supplementary Note 8) The information processing device according to Supplementary Note 7, wherein: the recognition result acquiring means is configured to acquire the recognition result information including object candidate information representing a candidate of an object recognized from the recognition target data by each of the plurality of object recognition engines, from each of the plurality of object recognition engines; and the integration recognition result acquiring means is configured to identify object information that corresponds to each other in accordance with a predetermined standard in the respective object candidate information acquired from the plurality of object recognition engines, and output as the new recognition result. [0065] (Supplementary Note 9) A computer program comprising instructions for causing an information processing device to realize: a recognition result acquiring means for acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data; and an integration recognition result outputting means for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, the computer program also comprising instructions for: causing the recognition result acquiring means to acquire the respective recognition result information in a data format common to the plurality of recognition engines, from the plurality of recognition engines; and causing the integration recognition result outputting means to integrate the respective recognition result information based on the respective recognition result information and output as the new recognition result. [0066] (Supplementary Note 10) The computer program according to Supplementary Note 9, comprising instructions for causing the integration recognition result outputting means to, when the respective recognition result information include information that correspond to each other in accordance with a predetermined standard, integrate the respective recognition result information and output as the new recognition result. [0067] (Supplementary Note 11) An information processing method comprising: acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data, the respective recognition result information being in a data format common to the plurality of recognition engines; and integrating the respective recognition result information based on the respective recognition result information acquired from the plurality of recognition engines, and outputting as a new recognition result. [0068J (Supplementary Note 12) The information processing method according to Supplementary Note 11, comprising: integrating the respective recognition result information and outputting as the new recognition result, when the respective recognition result information include information corresponding to each other in accordance with a predetennincd standard. [0069] (Supplementary Note 13) An information processing device comprising: a recognition result acquiring means for acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data: and an integration recognition result outputting means for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, wherein: the recognition result acquiring means is configured to: acquire the recognition result information including location information that represents a position of an object recognized from the recognition target data by an object recognition engine recognizing an object from the recognition target data and also represents a date and time when the object is recognized, the recognition result information being in a data format common to the plurality of recognition engines, from the object recognition engine; and also acquire the recognition result information including flow information of a predetermined object recognized from the recognition target data by a flow recognition engine recognizing a flow representing a trajectory of a predetermined object from the recognition target data, the recognition result information being in a data format common to the plurality of recognition engines, from the flow recognition engine; and the integration recognition result acquiring means is configured to, when the flow information acquired from the flow recognition engine includes information that corresponds to the location information acquired from the object recognition engine in accordance with a predetermined standard, integrate by relating the flow information that is the recognition result acquired from the flow recognition engine with object information identified by the recognition result information that is acquired from the object recognition engine and that includes the information corresponding to the location information, and output as the new recognition result. [0070] (Supplementary Note 14) An information processing device comprising: a recognition result acquiring means for acquiring respective recognition result information outputted by a plurality of recognition engines executing different recognition processes on recognition target data; and i an integration recognition result outputting means for outputting a new recognition result obtained by integrating the respective recognition result information acquired from the plurality of recognition engines, wherein: the recognition result acquiring means is configured to acquire the recognition result information including object candidate information representing a candidate of an object recognized from the recognition target data by each of a plurality of object recognition engines recognizing an object by different recognition processes from the recognition target data, the recognition result information being in a data format common to the plurality of recognition engines, from each of the plurality of object recognition engines; and the integration recognition result outputting means is configured to integrate by i identifying one object information that corresponds to each other in accordance with a predetermined standard in the respective object candidate information acquired from the plurality of object recognition engines, and output as the new recognition result. [0071] In each of the exemplary embodiments, the computer program is stored in the storage device or recorded in a computer-readable recording medium. For example, the recording medium is a portable medium such as a flexible disk, an optical disk, a magneto-optical disk and a semiconductor memory. [0072] The present invention has been described above with reference to the exemplary embodiments, but the present invention is not limited to the exemplary embodiments described above. The configurations and details of the present invention can be modified in various manners that can be understood by those skilled in the art within the scope of the present invention. [0073] The present invention is based upon and claims the benefit of priority from Japanese patent application No. 2011-031613, filed on February 17, 2011, the disclosure of which is incorporated herein in its entirety by reference. DESCRIPTION OF REFERENCE NUMERALS [0074] 10 intermediate-layer device 11 recognition-engine output acquiring unit 12 instance/class correspondence judging unit 13 output instance holding unit