The Stanford Photonics Research Center

Analog and Gray-scale-digital Compression for Video Stored in Volume Holographic Media

This invention increases the storage capacity for video images in holographic media by reducing the crosstalk between adjacent images. The method uses a differential approach, where changes with respect to a base image are recorded rather than the images themselves. The technique eliminates the recording of redundant images, such as background images, and thus reduces the average intensity of the stored pages. Reduced image intensities lead to reduced interpage crosstalk and increased data storage capacities. The differential technique also enables coherent video compression, which eliminates the need for the time-consuming encoding and decoding steps required in electronic compression. Thus, the invention enables a high capacity video image storage system with rapid readout capabilities.