A method of storing images of a scene, the method comprising: receiving an image of a scene; generating at least one image identifier of the image, the at least one image identifier being indicative of the content of the image; storing the at least one image identifier of the image in association with temporal information for that image in a first storage (1000a, 1100a); determining a degree of similarity between the content of the image and previous images which have been received based on a correspondence between the at least one image identifier of the image and the at least one images identifiers of the previous images in the first storage; storing the at least one image identifier of subsequently received images in a second storage (1002a, 1 100b) in association with temporal information corresponding to a first previous image when the determined degree of similarity between the image and the first previous image exceeds a predetermined threshold; determining the degree of similarity between the subsequently received images in the second storage and the previous images which have been received in the first storage based on a correspondence between the at least one image identifier of the subsequently received images and the at least one image identifiers of the previous images; and transferring the subsequently received images stored in the second storage to the first storage, in association with the temporal information of the first previous image, when the determined degree of similarity between the at least one subsequently received images and a second previous image exceeds a predetermined threshold. receiving an image of a scene; generating at least one image identifier of the image, the at least one image identifier being indicative of the content of the image; storing the at least one image identifier of the image in association with temporal information for that image in a first storage (1000a, 1100a); determining a degree of similarity between the content of the image and previous images which have been received based on a correspondence between the at least one image identifier of the image and the at least one images identifiers of the previous images in the first storage; storing the at least one image identifier of subsequently received images in a second storage (1002a, 1 100b) in association with temporal information corresponding to a first previous image when the determined degree of similarity between the image and the first previous image exceeds a predetermined threshold; determining the degree of similarity between the subsequently received images in the second storage and the previous images which have been received in the first storage based on a correspondence between the at least one image identifier of the subsequently received images and the at least one image identifiers of the previous images; and transferring the subsequently received images stored in the second storage to the first storage, in association with the temporal information of the first previous image, when the determined degree of similarity between the at least one subsequently received images and a second previous image exceeds a predetermined threshold.