Filtering Blob Data (Embedded SQL Guide)
Go Up to Working with Blob Data
An understanding of Blob sub-types is particularly important when working with Blob filters. A Blob filter is a routine that translates Blob data from one sub-type to another. InterBase includes a set of special internal Blob filters that convert from sub-type 0 to sub-type 1 (
TEXT), and from sub-type 1 (
TEXT) to sub-type 0. In addition to using these standard filters, you can write your own external filters to provide special data translation. For example, you might develop a filter to translate bitmapped images from one format to another.