A system comprising an information processing device comprising: an extraction unit that extracts ID information from a captured image of a superimposition image, the superimposition image containing a predetermined image and the ID information superimposed on the predetermined image, to determine admittance or non-admittance of entrance with an electronic ticket on the basis of the ID information, wherein the ID information indicates time radiance variations, wherein the extraction unit comprises: background determination unit configured to determine whether each of pixels contained in the captured image of one frame received is a background pixel, an integration unit configured to calculate, for each line, line integrated values by integrating pixel values of only background pixels in the pixels of the captured image received from the background determination unit on the basis of the pixel information received from the background determination unit, an integrated value storage unit configured to store the line integrated values, deviation calculation unit configured to obtain deviations of the line integrated values stored in the integrated value storage unit for one frame of the captured image, a separation unit configured to perform deconvolution for deviation of line integrated value received from the deviation calculation unit by using a shutter function expressing characteristics of the shutter of a camera to separate ID information superimposed on the captured image, and an error correction unit configured to perform majority decision for a plurality of items of ID information stored in the information storage unit; and an entrance admittance/non-admittance determination unit that determines admittance or non-admittance of entrance with the electronic ticket on the basis of the electronic ticket stored in a storage unit, and on the ID information. an extraction unit that extracts ID information from a captured image of a superimposition image, the superimposition image containing a predetermined image and the ID information superimposed on the predetermined image, to determine admittance or non-admittance of entrance with an electronic ticket on the basis of the ID information, wherein the ID information indicates time radiance variations, wherein the extraction unit comprises: background determination unit configured to determine whether each of pixels contained in the captured image of one frame received is a background pixel, an integration unit configured to calculate, for each line, line integrated values by integrating pixel values of only background pixels in the pixels of the captured image received from the background determination unit on the basis of the pixel information received from the background determination unit, an integrated value storage unit configured to store the line integrated values, deviation calculation unit configured to obtain deviations of the line integrated values stored in the integrated value storage unit for one frame of the captured image, a separation unit configured to perform deconvolution for deviation of line integrated value received from the deviation calculation unit by using a shutter function expressing characteristics of the shutter of a camera to separate ID information superimposed on the captured image, and an error correction unit configured to perform majority decision for a plurality of items of ID information stored in the information storage unit; and background determination unit configured to determine whether each of pixels contained in the captured image of one frame received is a background pixel, an integration unit configured to calculate, for each line, line integrated values by integrating pixel values of only background pixels in the pixels of the captured image received from the background determination unit on the basis of the pixel information received from the background determination unit, an integrated value storage unit configured to store the line integrated values, deviation calculation unit configured to obtain deviations of the line integrated values stored in the integrated value storage unit for one frame of the captured image, a separation unit configured to perform deconvolution for deviation of line integrated value received from the deviation calculation unit by using a shutter function expressing characteristics of the shutter of a camera to separate ID information superimposed on the captured image, and an error correction unit configured to perform majority decision for a plurality of items of ID information stored in the information storage unit; and an entrance admittance/non-admittance determination unit that determines admittance or non-admittance of entrance with the electronic ticket on the basis of the electronic ticket stored in a storage unit, and on the ID information.