To access feature type parameters, click the gear icon 
on a feature type in the workspace to open the Feature Type Parameter Editor. To always display the editor in Workbench, you can select View > Windows > Parameter Editor.
General
All feature types share similar General parameters, which may include the Feature Type Name, Reader or Writer Name, and Geometry.
In most Writer Feature Type parameter dialogs, you can also control Dynamic Schema Definitions. Some database formats accept a Table Qualifier prefix on the output table feature type.
These parameters apply only to a selected feature type, not to the entire writer.
Note: If a feature type parameter listed here conflicts with a writer-level parameter, then the writer parameter will be ignored and this feature type parameter will be used.
Raster Compression
Method
Sets the compression method for the raster.
Values: DXT, DXT1, DXT1A, DXT3, DXT5, ETC1
DXT1 and ETC1 produce approximately equivalent file sizes. DXT3 and DXT5 give file sizes two times the size of DXT1 and ETC1. DXT1 and ETC1 compressed files store RGB data while DXT3 and DXT5 store RGBA data. DXT1A is simply DXT1 compression with an alpha channel that can indicate full transparency or no transparency.
Default: DXT1
Quality
Sets the quality of the raster post-compression. Highest runs the slowest, but yields the best quality.
Values: Fastest, Fast, Normal, High and Highest
Default: Normal