Key Transition

Note  [Deprecated. This API may be removed from future releases of Windows.]

The Key transition performs keying based on RGB value, alpha value, hue or luminance.

The following image shows the key transition:

Key transition

Class ID (CLSID): {C5B19592-145E-11D3-9F04-006008039E37}

CLSID Variable Name: CLSID_DxtKey

Friendly Name: "DxtKey"


Property Type Valid range Description Applies To
Hueint0–360The hue value on which to key.Hue
InvertBOOLFALSE or TRUEBoolean value indicating whether to invert the default operation of the key. If FALSE, pixels in the overlying image are made transparent in the default manner. If TRUE, the operation inverts.Chroma, Hue, Luminance, Nonred
KeyTypeintSee RemarksSpecifies the type of key. For more information, see Remarks.All
Luminanceint0–100The luminance value on which to key.Luminance
RGBDWORD0x0 – 0xFFFFFFThe color on which to key. The value is a hexadecimal number with the format 0xRRGGBB, where RR is the red value, GG is the green value, and BB is the blue value. (Pure red, green, and blue are 0xFF0000, 0x00FF00, and 0x0000FF, respectively.)Chroma
Similarityint0–100The range of color data that becomes transparent. At higher values, a wider range of similar colors is transparent.Chroma, Nonred



The type of key that is performed depends on the value of the KeyType property, which must be one of the following:

Value Enumeration Description
0DXTKEY_RGBChroma key (key by RGB value).
1DXTKEY_NONREDNonred key. (Makes blue and green areas transparent.)
3DXTKEY_ALPHAKey by alpha value.
4DXTKEY_HUEKey by hue.


The key type defaults to DXTKEY_ALPHA.