Generation of thumbnail image from an image stored in compressed form in a database, uses storage of multiple sub-images of differing size and selects image nearest optimal display size for scaling

摘要

The thumbnail images are stored in the database as compressed multiple sub-images allowing extraction of images of different size. An optimum size is pre-determined (E115) and images extracted (E119). One sub-image is selected (E121) using a criterion of proximity of image size to optimal thumbnail, and the size of the selected sub-image is modified (E123) to obtain the optimal image size.