I

index palette

A DirectDrawPalette object whose entries are indexes into another palette object.

IPX service provider

A service provider that uses Windows Sockets to communicate over a local area network (LAN) using the Internetwork Packet Exchange (IPX) protocol. The service provider supports only nonguaranteed messaging. A single computer can host only one DirectPlay session using IPX.

IRE scale

International Radio Engineers scale. A scale of values ranging from 0 to 100 that defines the brightness level of a broadcast video signal. The spectrum of low-to-high IRE values describes increasing brightness levels of a video signal. At 7.5 IRE brightness—the black cut-off threshold for a National Television System Committee (NTSC) signal—the electron guns of an NTSC display device are cut off and do not display images.