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# Clipping region atom ('crgn')

An atom that specifies the clipping region.

## Overview

The clipping region atom contains the data that specifies the clipping region, including its size, bounding box, and region. Clipping region atoms have an atom type value of `'crgn'`.

The layout of the clipping region atom is as follows.

|Data field                                                                                            |Bytes   |
|------------------------------------------------------------------------------------------------------|--------|
|``doc://com.apple.qtff/documentation/quicktime-file-format/Clipping_region_atom/Size``                |4       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Clipping_region_atom/Type``                |4       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Clipping_region_atom/Region_size``         |2       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Clipping_region_atom/Region_boundary_box`` |8       |
|``doc://com.apple.qtff/documentation/quicktime-file-format/Clipping_region_atom/Clipping_region_data``|Variable|

## Topics

### Data fields

[`Size`](/documentation/quicktime-file-format/Clipping_region_atom/Size)

A 32-bit integer that specifies the number of bytes in this clipping region atom.

[`Type`](/documentation/quicktime-file-format/Clipping_region_atom/Type)

A 32-bit integer that identifies the atom type.

[`Region size`](/documentation/quicktime-file-format/Clipping_region_atom/Region_size)

The region size part of a QuickDraw region.

[`Region boundary box`](/documentation/quicktime-file-format/Clipping_region_atom/Region_boundary_box)

The region boundary box part of a QuickDraw region.

[`Clipping region data`](/documentation/quicktime-file-format/Clipping_region_atom/Clipping_region_data)

The clipping region data part of a QuickDraw region.


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