/*
 * ENUM: SE_LOOKUP_TYPE_ENUM
 *
 *   Used in <Image Lookup>.
 */

Enumerator Notes

SE_IMAGE_LOOKUP_YIQ_TO_RGB

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGB.

 Convert the RGB components of a texel into three indices
 that are used to derive intermediate values that are
 recombined into a single RGB triplet.
 First, the Y index into the translator table is derived from
 the red, green and blue components of the texel by the
 equation of the form: y_index = ( 0.299 * red_component)+
 (0.587*green_component)+(0.114*blue_component)
 This Y index points to a RGB triplet in the lookup table
 This triplet is then used to generate the intermediate Y
 value. Again Y=( 0.299 * red_component)+
 (0.587*green_component)+(0.114*blue_component)
 Next the I index is derived from the original texel RGB
 triplet by the equation I_index = (0.49804 * red_component) -
 (0.22896 * green_component) - (0.26908 * blue_component).
 This index points to another RGB triplet in the lookup table.
 This triplet is used to derive the intermediate I value by
 the equation I= (0.49804 * red_component) -
 (0.22896 * green_component) - (0.26908 * blue_component).
 The original RGB texel is used to generate the
 Q index by the equation q_index = (0.20093 * red_component) -
 (0.49804 * green_component) + (0.29711 * blue_component)
 This index points to another RGB triplet in the lookup table.
 This triplet is used to derive the intermediate Q value by
 the equation Q = (0.20093 * red_component) -
 (0.49804 * green_component) + (0.29711 * blue_component)
 Finally the intermediate Y, I , and Q values are combined to
 create the final displayed RGB triplet. The RGB triplet is
 derived by the equations:
 R = Y + ( 1.14423568 * I ) + ( 0.65258974 * Q )
 G = Y - ( 0.3263226  * I ) - ( 0.67923293 * Q )
 B = Y - ( 1.320834   * I ) + ( 1.7858368  * Q )

SE_IMAGE_LOOKUP_YIQ_TO_A

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_A.

 Converts the RGB components of a texel into an index
 that points to an alpha value. The index into the
 translator table is derived from the red, green, and
 blue components of the texel by an equation of the
 form:
 index = (0.299 * red_component)+
         (0.587*green_component)+
         (0.114*blue_component)

SE_IMAGE_LOOKUP_I_TO_I

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_I.

 The I component in the image is a pointer to the I value
    of the Ith element in the lookup table.

SE_IMAGE_LOOKUP_I_TO_A

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_A.

 The I component in the image is a pointer to the A value
    of the Ith element in the lookup table.

SE_IMAGE_LOOKUP_I_TO_IA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_IA.

 The I component in the image is a pointer to the I and A
    values of the Ith component in the lookup table.

SE_IMAGE_LOOKUP_IA_TO_IA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_IA.

 The I component in the image is a pointer to the I value
    of the Ith element in the lookup table.

 The A component in the image is a pointer to the A value
    of the Ath element in the lookup table.

SE_IMAGE_LOOKUP_I_TO_RGB

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGB.

 The I component is a pointer to the Ith element of the
    lookup table that contains the R, G, B, values.

SE_IMAGE_LOOKUP_RGB_TO_RGB

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGB.

 The R component is a pointer to the R value of the
    Rth element of the lookup table.

 The G component is a pointer to the G value of the
    Gth element of the lookup table.

 The B component in the image is a pointer to the B
    value of the Bth element in the lookup table.

SE_IMAGE_LOOKUP_I_TO_RGBA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGBA.

 The I component is a pointer to the Ith element of the
    lookup table that contains the R, G, B, and A values.

SE_IMAGE_LOOKUP_IA_TO_RGBA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGBA.

 The I component is a pointer to the Ith element of the
    lookup table that contains the R, G, B, values.

 The A component in the image is a pointer to the A value
    of the Ath element in the lookup table.

SE_IMAGE_LOOKUP_RGB_TO_RGBA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGBA.

 The R component is a pointer to the Rth element of the lookup
    table that contains the R value.

 The G component in the image is a pointer to the G value of
    the Gth element in the lookup table.

 The B component in the image is a pointer to the B value of
    the Bth element in the lookup table.

 The B component in the image is a pointer to the A value of
    the Bth element in the lookup table.

SE_IMAGE_LOOKUP_RGBA_TO_RGBA

 This lookup type is valid only when the <Image Lookup>'s
 lookup table signature is SE_LOOKUP_SIGNATURE_RGBA.

 The R component is a pointer to the Rth element of the lookup
    table that contains the R value.

 The G component in the image is a pointer to the G value of
    the Gth element in the lookup table.

 The B component in the image is a pointer to the B value of
    the Bth element in the lookup table.

 The A component in the image is a pointer to the A value of
    the Ath element in the lookup table.