Abstract: The invention relates to a method and a system for digitally processing of frequently updated images from a camera.

Abstract: A data storage and reduction method for digital images having a chronological order involves storing a first and chronologically new image or group of images at a first image quality requiring a first amount of storage space, and processing a second image or group of images, chronologically older than said first image or group of images, by reducing the image quality thereof to a second image quality requiring a second amount of storage space, which is less than said first amount of storage space. Advantageously, the method is used for a surveillance system, comprising a camera, a digital storage device and an image storage controller, wherein image quality is reduced for old or otherwise less important images or groups of images, thereby obtaining additional storage space for allowing more important images (such as images relating to an alarm event) to be stored at higher image quality, while retaining an extended total recording time span.

Abstract: An apparatus for storing digital images has a storage device [(134, 136) ] for storing a current reference image and a plurality of differential images, and an image processing device [(132) ] coupled to the storage device. The image processing device receives an individual digital image, determines a difference between the individual image and the current reference image, and stores this difference as a differential image in the storage device. The apparatus also has reference image updating means [(132)] for determining when to generate a new reference image, for generating the new reference image, for replacing the current reference image with the new reference image, and for storing the new reference image as current reference image in the storage device [(134, 136)].