DDS (file format)

Description

The DirectDraw Surface graphics file format was established by Microsoft for use with the DirectX SDK. The format is specifically designed for use in real-time rendering applications, such as 3D games. It can be used to store textures, cubemaps, mipmap levels, and allows for compression. Due to the fact that most video cards natively support DXTn texture compression, use of this format can save memory on the video card.

Drivers can perform this compression on the fly thanks to the GL_ARB_texture_compression extension. Thus, it would appear the only advantage of DDS is just reduced space (meaning faster loading) without "double degradation" caused by recompressing already-compressed formats like JPEG. However, DDS files expose this automated process to artists. This allows the image author to correct or prevent artifacts that might occur in a completely automated compression process, or even emphasize specific parts of an image's MIP maps.

General File Format Specifications

Type	Raster Image Format
Extension	*.DDS
Compression	None, DXTn
Color Depth	1- to 32-bits

Notes

To convert an image to DDS, you can use the same tool id used: The Compressonator from ATI.

• To create DDS files in Photoshop you must download the Nvidia DDS plugin.
• To create and edit DDS files in The Gimp, you must download a DDS plugin.

See the Texturing page for which DXTn method to use depending on the image.

Sources