Method and apparatus for image compression, storage, and retrieval on

Abstract

A transaction card is described in which data representing an identifiable image can be stored in a limited amount of storage space. The image to be stored is converted to an associated matrix of pixel values. The matrix of pixel values is partitioned into a plurality of ordered image portions corresponding to a like partitioning of the image. The partitioning is generally related to feature locations in the image. Each image portion is compared with a reference set of image portions represented by pixel groups. Associated with each pixel group is a signal group. For each image portion, a signal group is chosen for the associated reference pixel group that most closely matches with the pixel image portion. The signal groups representing the matrix of pixel values or the image to be stored are stored as bit patterns on the storage space of a transaction card. The bit patterns may then be read and converted to the signal groups. From the signal groups, a reference pixel group is identified from within a reference set and the reference pixel group is positioned with respect to the image at the same location as the image portion. Using this technique, a recognizable image can be constructed from image information compatible with the ISO-7811/2 standards.