Why should I use ASTC?

Adaptive Scalable Texture Compression or ASTC is a major step forward in terms of image quality, reducing memory bandwidth and thus energy use. It also offers a number of advantages over other texture compression schemes:

  • Flexibility, with bit rates from 8 bits per pixel (bpp) down to less than 1 bpp. This allows content developers to fine-tune the tradeoff between quality versus texture size and upload bandwidth.
  • Support for 1 to 4 color channels, with modes for uncorrelated channels for use in mask textures and normal maps.
  • Support for both low dynamic range (LDR) and high dynamic range (HDR) images.
  • Support for both 2D and 3D images.

ASTC specification includes two profiles: LDR and Full. Both of these are supported on the latest Mali GPUs. The smaller LDR Profile supports 2D low dynamic range images only. It is designed to be easy to integrate with existing hardware designs that already deal with compressed 2D images in other formats. The LDR Profile is a strict subset of the Full Profile, which also includes the 3D textures and high dynamic range support.

ASTC and ETC2 comparison demo

The benefit of ASTC is that it has many texture compression options that allow the artist to specify the desired quality and memory footprint characteristics very precisely.  In this video we show comparisons of memory usage and image quality between raw, ETC2, ASTC 5×5 and ASTC 6×6.

The overall result when textures are compressed with ASTC is an improved image quality, lower bandwidth usage and significantly reduced energy consumption.

See more Mali graphics demos

Further information

ASTC technology
Learn more about the ASTC technology

ASTC Evaluation Codec on Github
Check out the ASTC repository on Github and try it yourself

ASTC is fully supported in Unity
See Unity's docs for more information

ASTC is also fully supported in the Unreal Engine from Epic
See Epic's docs for more information

Arm unveils details of ASTC texture compression
See blog which introduced ASTC

ASTC Texture Compression: Arm pushes the envelope in Graphics technology
Read more about ASTC in this blog

Saving System Power with Arm Multimedia IP
Learn more about system power saving techniques for the whole Arm multimedia system in this blog