32-bit OpenEXR support

OpenColorIO Integration

With an OpenColorIO configuration (see OpenColorIO for more information), OpenEXR documents with a valid colour space affix (eg filename_acescg.exr) will be converted from that colour space to scene_linear upon import.

Additional configuration

Additional OpenEXR options are available from the Colour options on the Preferences menu:

• Associate OpenEXR alpha channels—when enabled, alpha channel information is merged to its associated RGB pixel layer's alpha channel. By default (disabled), imported alpha channels are imported as separate layers with an .A affix.
• Post divide EXR colours by alpha—when enabled, divides colour channels by the alpha channel.
• Perturb zero EXR alpha—when enabled, alters zero alpha information so post-division with colour channel information can be achieved if Post divide EXR colours by alpha is enabled. By default (disabled), zero alpha information is left untouched.

Multichannel import/export

Photo supports multichannel OpenEXR documents for both import and export.

Multichannel import:

• Each channel is imported to a discrete layer in the Layers Studio.
• Each layer retains its affix (e.g., .RGBA, .XYZ).
• Layers can be hidden or shown and edited individually.

Multichannel export:

• Each discrete layer with its channel affix (e.g., .RGBA) is exported to its own channel.
• All layers are exported to channels regardless of whether they are hidden or shown at the time of export.
• In order to export as multichannel OpenEXR, either the correct preset must be chosen, or the multichannel setting must be enabled on the OpenEXR export dialog. See below for more information.

To export a multichannel OpenEXR document:

1. From the Document Menu, choose Export.
2. Select the EXR export format.
3. From the Preset dropdown, select OpenEXR 32-bit linear (layered).
4. (Optional) Configure additional settings:
   • Compression—determine a compression format to use for a reduced file size. Compression may also be disabled entirely.
   • Image Pixels—choose whether to encode Image channels (RGBA etc) as 16-bit (half float) or 32-bit (full float).
   • Spatial Pixels—choose whether to encode Spatial channels (XYZ etc) as 16-bit (half float) or 32-bit (full float).
   • Other Pixels—choose whether to encode other/undetermined channels as 16-bit (half float) or 32-bit (full float).
   • Colour profile from name—converts to the given colourspace name on export (eg filename_aces.exr). Requires a valid OpenColorIO configuration.
   • Multichannel—enables multi-channel (layered) export.
   • Include unknown channels—channels whose type cannot be determined will still be exported as a single luminance-based channel.
5. Choose Export to export the document to a chosen filename and directory.