The content of the compressed file is important to the description of the original information. One example of possible data loss is shown in Figure 1. This is the result of a simulation performed at the Information Technology Laboratory at NIST as part of a research program on the data integrity of advanced optical storage subsystems. In this simulation, a corrupted byte has been introduced on an image file. The simulation demonstrates that if stored uncorrectable data is recovered, a particular decoder might not be able to represent the image without data loss.
Uncompressed data can also suffer serious data loss.
Intelligent data storage devices are emerging that provide the host with sophisticated MEMR techniques and the associated data integrity metadata. This metadata is used by data storage software management applications. Some of them deliver this metadata to the host upon request. However, until recently, these tools and the associated metadata have not been standardized. These tools and the associated data integrity metadata enables users of optical disk libraries to verify the integrity of stored data both initially, when data are transferred to the media, and periodically when monitoring the status of data.