Image data output processing apparatus and image data output processing method excelling in similarity determination of duplex document

A control device for use in an image data output processing apparatus which carries out an output process with respect to input image data, the control device comprising:

• an image matching section that (i) extracts features of an image of the input image data, and (ii) carries out a determination as to a similarity between the image of the input image data and an image of a reference document based on a comparison made between the features extracted and features of the image of the reference document stored in advance;
• and an output process control section that controls the output process with respect to the input image data based on a determination result made by the image matching section, wherein the image matching section carries out a matching of the image of the input image data by use of a storage section which stores (i) features of each of images on a front side and a back side of a duplex reference document and (ii) an index for identifying a duplex document including the reference image, the index being stored so as to correspond to an index for identifying each of the images on the front side and the back side of the duplex document, the image matching section including:
• a voting process/candidate list creation section that extracts, in a case where the input image data is of a duplex document, for each of the images on the front side and the back side of the duplex document, (i) a reference image index of a reference image having a similarity which is not less than a predetermined value from the storage section and (ii) a reference document index corresponding to the reference image index from the storage section, so as to create a front side candidate list and a back side candidate list;
• and a duplex document determination process section that determines, in a case where each of the front and back side candidate lists created include a reference image index that corresponds to an identical reference document index, that the images on the duplex document of the input image data are similar to the reference images that have the identical reference document index, respectively.

An image data output processing method for carrying out an output process with respect to input image data, said method comprising:

• an image matching step of (i) extracting features of an image from the input image data and (ii) carrying out a determination as to a similarity between the image of the input image data and an image of a reference document based on a comparison made between of the features extracted and features of the image of the reference document stored in advance;
• and an output process control step of controlling the output process with respect to the input image data based on a determination result made by the image matching section, wherein the image matching step carries out a matching of the image of the input image data by use of a storage section which stores (i) features of each of images on a front side and a back side of a duplex reference document and (ii) an index for identifying a duplex document including the reference image, the index being stored so as to correspond to an index for identifying each of the images on the front side and the back side of the duplex document, the image matching step further including:
• a voting process/candidate list creation step of extracting, in a case where the input image data is of a duplex document, for each of the images on the front side and the back side of the duplex document, (i) a reference image index of a reference image having a similarity which is not less than a predetermined value from the storage section and (ii) a reference document index corresponding to the reference image index from the storage section, so as to create a front side candidate list and a back side candidate list;
• and a duplex document process step of determining, in a case where each of the front and back side candidate lists created include a reference index that corresponds to an identical reference document index, that the images on the duplex document of the input image data are similar to the reference images that correspond to the identical reference document index, respectively.