SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
The Weighted Average block implements the equation shown on Figure 6-103.
In the equation on Figure 6-103 the Weights (W1*) are 12 bits signed with a range of -8 to +7.9996 in S12Q8 format. The offset is Signed 13 bits in S13Q11 format with a range of -2 to +1.995.
Figure 6-104 depicts the archtiectue of the Weighted Average block:
The mux before the matrix chooses whether the native R/B channels are transmitted or alternatively the Min/Max (RGB) from the Min-Max block are transmitted. Further, the calculation of V can work on either the non-WB corrected data or the WB corrected version. For more information about WB correction, see Section 6.7.3.6.3.3.3.2, Saturation Block.
The combination of the Min-Max block, the mux and the Weighted Matrix allows any of the Gray Scale calculation as shown in Table 10-180.
No | Formula | Configuration |
---|---|---|
Grey scale (HSI) | (R+G+B) / 3 | H1 = R, H2 = B; Offset_1 = 0; W1 = W2 = W3 = 1/3 = 85; |
Gray Scale (HSV) | Max(RGB) | H1 = Max(RGB); H2 = NA Offset_1 = 0; W2/W3 = 0; W1 = 1 (256); |
Gey Scale HSL | (Max(RGB) + Min (RGB)) / 2 | H1 = Max(RGB), H2 = Min(RGB); W1 = W2 = 0.5 (128) Offset_1 = 0; W3 = 0; |
H1 = R, H2 = G; W1 = W3 = 0.25 (64); W2 = 0.5 (128) Offset_1 =0 |
No | HSI Color Space | HSV Color Space | SHL Color Space | Customer Requirements |
---|---|---|---|---|
Grey Scale Computation | (R+G+B) / 3 | Max(R,G,B) | (Max(R,G,B) + Min(R,G,B)) / 2 | (R+2*G+B) / 3 |
Saturation (S) Computation | 1-(Min(R,G,B) / (R+G+B)) | (Max(R,G,B) - Min(R,G,B)) / Max(R,G,B) | (Max(R,G,B) - Min(R,G,B)) / 255-Gray value | S = Max(R,G,B) - Min(R,G,B) |
Hue (H) Computation | Complex formula involving (R-G) (R-B) & (G-B) | Division formula Iivolving (R-G) (R-B) & (G-B) | Complex formula involving all component | Separate output for (R-G) and Yellowness |