Ericsson Texture Compression (ETC1) Container Format

PKM Format Hub - Online PKM Converter & ETC1 Texture Viewer

Comprehensive online PKM format resources crafted for the Android ecosystem. Use an easy PKM Converter (PNG/JPG to PKM) and a detailed PKM viewer for robust ETC1 compressed files.

About PKM Format

PKM (Ericsson Texture Compression) is a simple, efficient container format designed specifically for ETC1 compressed textures. It has become a standard format in mobile game development, particularly on Android platforms.

Lightweight Structure

Minimal file header overhead, optimized for fast loading and parsing on mobile devices.

ETC1 Compression

Uses ETC1 compression providing 6:1 compression ratio for RGB textures with hardware decoding support.

Wide Hardware Support

Supported by all OpenGL ES 2.0+ devices, ensuring compatibility across Android ecosystem.

Simple Format

Straightforward specification makes it easy to implement custom readers and writers.

Technical Specifications

File Structure

  • 16-byte header containing magic number, version, format type, and dimensions
  • Raw ETC1 compressed texture data following the header
  • Optional mipmap chain stored sequentially

Compression Details

Type:
ETC1 (Ericsson Texture Compression 1)
Block Size:
4×4 pixels per block
Ratio:
6:1 compression ratio (4 bits per pixel)
Quality:
Optimized for natural images and diffuse textures

Limitations

  • ETC1 does not support alpha channel (RGB only)
  • Optimal performance with square, power-of-two textures
  • May show artifacts on textures with sharp color transitions

Common Use Cases

Mobile Game Development

Primary texture format for Android games requiring hardware-accelerated decompression and efficient memory usage.

Diffuse Textures

Ideal for diffuse maps, environment textures, and UI elements without transparency.

Legacy Android Support

Essential for games targeting older Android devices with OpenGL ES 2.0.

Asset Pipeline Integration

Widely supported by game engines and texture compression tools for automated workflows.

PKM vs Other Formats

ktx

KTX offers more flexibility with multiple compression formats but has larger overhead

astc

ASTC provides better quality and alpha support but requires newer hardware (OpenGL ES 3.0+)

pvr

PVR is optimized for PowerVR GPUs but has limited support on non-PowerVR devices

png

PNG is lossless but much larger file size and requires CPU decompression

Related Tools & Resources

External Tools

  • ARM Mali Texture Compression Tool
  • Imagination PVRTexTool
  • Android SDK etc1tool utility

Related search entrypoints

PKM Format Hub - Online PKM Converter & ETC1 Texture Viewer | Texture Compression Online