ImageSignature is a self-contained, highly-reliable method for tracking and verifying BD images as they move through the disc manufacturing process – from authoring to final QC.
ImageSignature Version 2.0 incorporates a new structure to better handle BD process. It provides fast layer checking capability, self-verification, and a simpler manual signature input and display. Newer versions of EclipseSuite will automatically incorporate this new signature structure.
One Signature – Authoring to Replication
A key characteristic of ImageSignature is that the same signature can be derived from an image at any point in the process. Any time an image is tested with any of the EclipseSuite programs, the signature is validated and reported. The image signature validation is always performed on unencrypted or decrypted data. When decryption is required, the process is fast and automatic.
Simpler User Interface
EclipseSuite BD present the last 6 bytes (12 characters) of the 20-byte signature value to the user. This easily recognizable short form of the signature can be entered into ImageVerify when manual signature entry is necessary.
Quick Layer Check
The primary signature can be used detect layer mismatches, but only after the entire image is read. However, the new Layer Match Hash, since it contains only limited information from each layer, can report a layer mismatch almost instantly. The Layer Match Hash is created from specific, limited data from each layer that is easily and quickly accessed.
Since every ImageSignature 2.0 disc has its signature stored on it, ImageVerify can use that signature to validate the image integrity. This self-verification process is limited and should be used cautiously since it is somewhat self-fulfilling. Because the signature and data always stays together in the CMF, if the data is correct, the signature should always match. The self-verify rule should trigger a failure only in cases where a glass mastering formatter corrupted the data or in a case where the data cannot be read accurately by the drive. It will not detect image mixing problems (e.g. the mastering operator chose the wrong image) and should only be used if replicas are checked for mixing elsewhere in the process.
Specification – Version 2.0 Signature for BD
In order to create a signature that remains constant through the entire manufacturing process, it is necessary to exclude certain data from the signature calculation that is known to change as the image moves through encryption and mastering. It is important to note that the excluded data does not include user data and is checked by other means during the image analysis, so image integrity is guaranteed.