Area scan cameras are widely used in industrial manufacturing for quality controlling, production monitoring, or defect inspection. The area scan cameras are normally integrated in a single sensor covered by the Bayer color filter array for RGB signal capturing, and the raw image with one channel for each pixel is obtained in one exposure.

Therefore, it is significant to reconstruct the other two channels at each pixel which is called demosaicking.

In this article, one hybrid demosaicking algorithm is proposed by a research team led by Prof. Dr. SUN Bangyong  from Xi'an Institute of Optics and Precision Mechanics (XIOPM) of the Chinese Academy of Sciences (CAS) based on fuzzy edge strength and residual interpolation (RI) method.

They first demosaic the G channel with one edge-directed filter and refine the high textured details by using fuzzy edge strength interpolation. Then, the RI is employed to calculate R and B channels, where G is used as the guide image for computing residuals.

In the experiment, they evaluate our proposed method with nine prevalent interpolation-based algorithms on the IMAX and Kodak image datasets. The experimental results demonstrate that the proposed algorithm outperform the others by synthesizing the performance in peak signal-to-noise ratio, structural similarity, visual comparison, and computational time.

Tworepresentative test images from the Kodak and the IMAX datasets. (Image by XIOPM)

(Original research article “IEEE Transactions on Industrial Informatics” (2020) https://doi.org/10.1109/TII.2019.2959069 )