Comparison of Interpolation Methods in Bayer CFA Image Compression Based on Structure Separation and APBT-JPEG

The color filter array (CFA) captures only one-third of the necessary color intensities and the full color image is generated from the captured data by interpolation. In recent years, the algorithm of Bayer patterned image compression based on “structure separation” has achieved better image quality. On the basis of previous work, the algorithm based on the all phase biorthogonal transform (APBT) and interpolation is proposed in this paper. Instead of the conventional DCT-JPEG, the APBT-JPEG significantly reduces complex multiplications and makes the quantization table easier. Several kinds of interpolation methods to the decompressed image data are also discussed in this paper, including nearest neighbor interpolation, bilinear interpolation, cubic convolution interpolation and a novel interpolation method based on APIDCT. Experimental results show that the proposed algorithm outperforms the one based on “structure separation”; and the APIDCT interpolation performs close to the conventional interpolation methods and behaves better than them at high bit rates.