Robust AF,AE,and AWB control

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Robust AF,AE,and AWB control Modified block
diagram

• B88901136 ???

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Block diagram in this paper
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AF Algorithm

• flow chart of the AF algorithm
• Point
• 1.Valley-Descending Control
• 2.Hill-Climbing control
• Windows 1 whole frameWindows 2 center frame

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AF Algorithm(1) Valley-Descending Control

• High luminance/Contrast object
• Avoid go into de-focus state

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AF Algorithm(2) Hill-Climbing control

• Low luminance/Contrast object
• fiL moving the direction of the lens since the
  skirt area of the curve has a steeper slope.fiH
  finding the peak since it has a steeper slope in
  the in-focus range of the curve.

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AE Algorithm

• Luminance difference Db for backlighting
  detectionDbR0max(R2,R3)-(R1R4)
• R1,R4 are more weighted using the normalized
  degree of backlighting ,Nb, than that of the
  background regions.(according to the transfer
  function)

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AWB Algorithm(1)

• Using the color difference signals
  (R-G,B-G).Adjust the R gain B gain let R-G
  B-G go into the shaded area.
• -altB-Glta -bltR-Gltb-clt(R-G)(B-G)ltc

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AWB Algorithm(2)

• Color compensationconvert the R and B gains into
  appropriate values with narrow shaded areas.
• RminltRltRmaxBminltBltBmaxT1ltR3BltT2

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Simulation result conclusions

• Test scene with light source.
• 1.Valley-Descending Control
• 2.Hill-Climbing control

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Modified Project Block Diagram
Image Source
Get the image to the pipeline for comparison
Black Clamp

• CFA Interpolation

RGB CFA with Edge color correction
1.Preset Gain Factor 2.White Reference Area 3.AWB
range
Gain Factor WB
Hue WB
Auto WB
False color suppression
Pixel Value Gamma correction
NOT raw file Related to Vin Vout of LCD
Max pixel value is 255
LCD Display Gamma correction
YUV conversion
NOT raw file
JPEG compression
Flash memory
LCD screen