An image processing apparatus comprising: an acquisition means configured to acquire image data of an image captured by an image capturing apparatus in a time interval, via a network; and an analysis means configured to execute analysis processing of tracking a moving object based on the image data acquired by the acquisition means, the image processing apparatus being characterized in that: the acquisition means is configured to determine that the image analysis processing is executed by the analysis means with insufficient information in a case where the analysis means cannot detect the moving object and to acquire, via the network, additional image data captured by the image capturing apparatus in the said time interval that is different from the image data having been used for the analysis processing, wherein the additional image data includes at least one additional frame existing between the frames having been used for the analysis processing, and the analysis means is configured to execute reanalysis processing of the image data captured in the interval by using the additional image data wherein the analysis means executes, by using the additional image data, the reanalysis processing on image data with a higher frame rate compared with the analysis processing before the additional image data is added to improve an accuracy of the analysis processing in the interval where image data for the analysis processing is insufficient. an acquisition means configured to acquire image data of an image captured by an image capturing apparatus in a time interval, via a network; and an analysis means configured to execute analysis processing of tracking a moving object based on the image data acquired by the acquisition means, the image processing apparatus being characterized in that: the acquisition means is configured to determine that the image analysis processing is executed by the analysis means with insufficient information in a case where the analysis means cannot detect the moving object and to acquire, via the network, additional image data captured by the image capturing apparatus in the said time interval that is different from the image data having been used for the analysis processing, wherein the additional image data includes at least one additional frame existing between the frames having been used for the analysis processing, and the analysis means is configured to execute reanalysis processing of the image data captured in the interval by using the additional image data wherein the analysis means executes, by using the additional image data, the reanalysis processing on image data with a higher frame rate compared with the analysis processing before the additional image data is added to improve an accuracy of the analysis processing in the interval where image data for the analysis processing is insufficient. the acquisition means is configured to determine that the image analysis processing is executed by the analysis means with insufficient information in a case where the analysis means cannot detect the moving object and to acquire, via the network, additional image data captured by the image capturing apparatus in the said time interval that is different from the image data having been used for the analysis processing, wherein the additional image data includes at least one additional frame existing between the frames having been used for the analysis processing, and the analysis means is configured to execute reanalysis processing of the image data captured in the interval by using the additional image data wherein the analysis means executes, by using the additional image data, the reanalysis processing on image data with a higher frame rate compared with the analysis processing before the additional image data is added to improve an accuracy of the analysis processing in the interval where image data for the analysis processing is insufficient.