---
title: "Compressed matte atom ('kmat')"
framework: quicktime-file-format
role: symbol
role_heading: Atom
path: quicktime-file-format/compressed_matte_atom
---

# Compressed matte atom ('kmat')

An atom that specifies the image description structure and the matte data associated with a particular matte atom.

## Overview

Overview The compressed matte atom specifies the image description structure and the matte data associated with a particular matte atom. Compressed matte atoms have an atom type value of 'kmat'. The layout of the compressed matte atom is as follows.  |   |   |   |   |   |   |

## Topics

### Data fields

- [Size](quicktime-file-format/compressed_matte_atom/size.md)
- [Type](quicktime-file-format/compressed_matte_atom/type.md)
- [Version](quicktime-file-format/compressed_matte_atom/version.md)
- [Flags](quicktime-file-format/compressed_matte_atom/flags.md)
- [Matte image description structure](quicktime-file-format/compressed_matte_atom/matte_image_description_structure.md)
- [Matte data](quicktime-file-format/compressed_matte_atom/matte_data.md)

## See Also

### Describing tracks

- [Track atom ('trak')](quicktime-file-format/track_atom.md)
- [Track header atom ('tkhd')](quicktime-file-format/track_header_atom.md)
- [Track exclude from autoselection atom ('txas')](quicktime-file-format/track_exclude_from_autoselection_atom.md)
- [Track aperture mode dimension atoms](quicktime-file-format/track_aperture_mode_dimension_atoms.md)
- [Clipping atom ('clip')](quicktime-file-format/clipping_atom.md)
- [Clipping region atom ('crgn')](quicktime-file-format/clipping_region_atom.md)
- [Track matte atom ('matt')](quicktime-file-format/track_matte_atom.md)
- [Edit atom ('edts')](quicktime-file-format/edit_atom.md)
- [Edit list atom ('elst')](quicktime-file-format/edit_list_atom.md)
- [Playing with edit lists](quicktime-file-format/playing_with_edit_lists.md)
- [Track load settings atom ('load')](quicktime-file-format/track_load_settings_atom.md)
- [Track reference atoms](quicktime-file-format/track_reference_atoms.md)
- [Track input map atoms](quicktime-file-format/track_input_map_atoms.md)