Zoomen mit vorbestimmten Grössen von Indexbildern

Disclosed are method and apparatus for the manipulation of thumbnail images as used in image-based browsing file management systems. Disclosed are arrangements whereby zooming in and out of thumbnail images can be performed without a continued need to decompress a true image thus providing for faster operation. Pixel interpolation and/or replication are used to generate intermediate images that are display to deliver to the user a perception of a transitory zoom yet are of sufficient detail to maintain user orientation. Aspect ratio zooming of thumbnail containment areas is also disclosed which facilitates ease of browsing. The compression of thumbnail type images using a discrete wavelet transform facilitates the fast zoom of thumbnails and their associated containment areas.