Before images can be queried by content, they must be cataloged in a QBIC catalog. A QBIC catalog holds data about the visual features of images.
You create a QBIC catalog for each column of images in a user table that you want to make available for querying by content. There can be no more than one QBIC catalog for each column of images in a user table, and multiple columns cannot share the same QBIC catalog.
When you create a QBIC catalog, you identify the features for which you want the Image Extender to store data. You also indicate whether you want the Image Extender to automatically catalog an image. Automatic cataloging means the Image Extender will automatically create entries for an image in the catalog when the image is stored in a user table. If the image is not automatically cataloged, you must manually catalog it. This means that you explicitly tell the Image Extender to create entries in the catalog for the image.
After you create a QBIC catalog, you can:
You can use APIs that are provided by the Image Extender to perform these tasks, including creating a QBIC catalog. You can also perform many of the tasks by using the db2ext command-line processor.