1. An embroidery region detection apparatus comprising: an embroidery frame information acquisition unit that acquires information with respect to an embroidery frame and information with respect to a mark alignment region to be displayed on a display unit for guiding a plurality of marks provided to the embroidery frame for defining an embroidery region within the embroidery frame; an image acquisition unit that acquires an image of the embroidery frame when the plurality of marks displayed on the display unit are all positioned within the mark alignment region; an acquired image analyzing unit that performs image analysis based on the information with respect to the embroidery frame acquired by the embroidery frame information acquisition unit and corresponding information with respect to the plurality of marks displayed in the image acquired by the image acquisition unit; and an embroidery region determination unit that determines the embroidery region within the embroidery frame based on an analysis result obtained by the acquired image analyzing unit.