Autodesk 62205-051408-9001 User Guide - Page 605

Setting Bit Depth ❚❘❘ Promoting and Demoting Bit Depth When you increase bit depth, you introduce no new color information to the original images. Subsequent operators can take advantage of the increased number of possible colors. The following diagram illustrates the color mapping concept. Color Mapping for Promoting Bit Depth Setting Bit Depth There are five places to set the bit depth of your work: • Footage operator • Composite operator • Edit operator • Bit Depth Converter operator • Render Queue dialog (and other rendering dialogs) These places correspond to points in the flow of image data in a project: input, mid-stream, and output. You start with the bit depth of footage initially set by the file format. In the Footage operator, you can choose to change the bit depth. 8 bit 10 bit 10 bit File format of footage Change bit depth in Footage operator Input colors Output colors Just as you can increase (or promote) the bit depth, you can decrease (or demote) the bit depth. When bit depth changes, the input colors are mapped (or converted) to the output colors. A Lookup Table (LUT) describes specific pixel values used in the conversion; all the pixel values are represented by plotting the input and output colors. LUTs are especially useful for converting between a logarithmic image and a linear image while maintaining color accuracy. For more information, see Using Lookup Tables. The various pieces of footage used for layers in a composite can each have a different bit depth. The composite can change the bit depth. 10 bit 10 bit 10 bit Change bit depth in 8 bit Composite operator As you work on footage (for example, a layer of a composite), you can add a series of operators like the Keyer and Color Corrector. You can promote and demote bit depth mid-stream using the Bit Depth Converter operator. 589