AmebaPro2_FastCameraStart_AE_AWB_Flow

◼ Fast camera start (FCS) flow

Basic concept for AmebaPro2 Fcs flow

  • Bring Up Sensor at rom code (before ISP turn on) to reduce bring up time

  • Reference initial value is based on Ambient light sensor

    • Which can provide approximate luminance to real scene

    • Need to guess color temperature

    • FOV of ambient light sensor would be not same as lens with cmos sensor

  • Use fast auto exposure (AE) and fast auto white balance (AWB) method to improve convergence time

    • Use one step method for each convergence until reaching target

    • Both for AE & AWB

ISP mechanism limitation

  • Take a one-step approach to reach AE & AWB target

  • Without adopt advanced statistic flow

    • Such as dynamic ae adjustment by histogram, preference for WB gain,auto WDR level adjustment…

    • Even with suitable initial value, it would also see some image quality adjustment

    • But with good image quality also

image1

◼ Real scene comparison

image2

image3

◼ Suggestion method

◼ Refer to ALS value to set initial AE & AWB value

  • It is suggested that use frame 1 as first frame (drop 1 frame)

◼ Due to FOV of ALS isn’t perfect same as lens FOV

  • If lens fov is too larger than ALS, it is suggested that use frame 4 as first frame (drop 4 frame)

  • Let fast AE mechanism to do at least 1 convergence