Image Signal Processing Algorithm and Software

3A (AE/AF/AWB) Software IP


Auto control technologies for exposure and focusing are very important to get good images under the conditions that lighting or shooting object changes. CIS developed 3A software IP to work with “ClairvuTM” ISP. CIS offers software solution to meet customers’ various needs.

Key Characteristics
  • Collaborative processing of “ClairvuTM” ISP and micro-controller enables AE (Auto Exposure), AF (Auto Focus), and AWB (Auto White Balance).
  • 3A (AE/AWB/AF) ソフトウェアIP

  • Auto Exposure

    According to the detected luminance conditions, diaphragm (lens iris), gain level, and shutter speed are controlled to keep the brightness of the image constant. Various types of exposure metering schemes, such as center-weighted metering, spot exposure metering, and area exposure metering, are corresponded.

  • Auto Focus

    Contrast detection method that defines the focus position for the maximum contrast as the full focus.
    Eliminating signal noises as much as possible, auto focus function is effective even for difficult scenes, such as the one under low illumination, telescopic zooming, and others.

  • Auto White Balance

    Human eyes are color flexible and sense the original colors even when the illuminating light source changes. To acquire natural images, cameras need to have a similar function to human eyes, in other words, the function to correct the color depending on illuminating conditions. This is a so-called “White Balance” function.
    In addition to the conventional AWB to make the average color of the image be close to gray, CIS developed auto white balance algorithm to control its balance more precisely, estimating the color of the lighting source.

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