2017

■ video transitions
■ making gradients
Operations That Require Video Colors
Some operations require video colors, that is, colors that are restricted to the range [0, 1]. These operations
include:
■ color inversion
■ converting RGB to HLS, HSV, or YCbCr
Common Color Management Scenarios
Although there's an unlimited number of possible situations that you may encounter in color management,
they can be divided into categories that require similar treatment.
Color Managing Images on Input
When importing images, you should apply color transforms to convert them to a connection space and
then to your chosen working space. Different types of images require different transforms.
In general, you need to apply two transforms to input images:
1 Convert images from their source space to a connection space. Several transforms are available:
■ Use the transforms in the camera/ directory to import images from various digital cinema cameras
and convert them to ACES.
■ Use the transforms in the film/ directory to import scanned film plates in ADX or another
Cineon-style log encoding and convert them to ACES.
■ Use the transforms in the display/ directory to import video images in HD, SD, or DCI formats and
convert them to linearized output-referred CIE XYZ.
■ Use the transforms in the interchange/ directory to import other common color spaces and convert
them to linearized output-referred CIE XYZ.
2 Once images have been imported and converted to ACES or CIE XYZ, you can use the other transforms
to convert them to your working space. (However, keep in mind that a tone-map transform is needed
when converting between scene-linear and output-referred color spaces.)
For example, suppose that you want to work with scene-linear values using the ProPhoto primaries. First
convert the inputs to ACES, then apply ACES_to_CIE-XYZ followed by CIE-XYZ_to_ProPhoto-RIMM from
the primaries/ directory. If desired, you can export a custom .ctf file that applies all three transforms in order.
On the other hand, if you want to import raw digital cinema camera footage and work with it using
video-encoded values, you can import the images using the appropriate transform from the camera/ directory
and then apply one of the transforms in the RRT+ODT/ directory.
If you need to convert Digital Cinema Distribution Master (DCDM) values to HD video, you can apply
DCI_to_CIE-XYZ from the display/DCDM/ directory followed by CIE-XYZ_to_HD-video from the
display/broadcast/ directory assuming that the DCDM was mastered to the DCI calibration white point.
However if this results in unequal RGB values for colors that are supposed to be neutral, then you may need
to replace the first transform with one that is relative to a different white point, such as DCI-D65_to_CIE-XYZ
(see
White Point Conversion (page 1318)).
Autodesk Color Management | 1311