Adjacent picture elements division of focal plane (DoFP) polarizing camera have different polarization directions, which will result in a loss of imaging resolution. Bilinear interpolation and sliding window algorithms can improve the imaging resolution, therefore, this paper analyzes the mathematical relationship between bilinear interpolation and sliding window algorithms, and degree of linear polarization (DoLP) values are calculates after processing at the edges. The analysis shows that the Stoke vector obtained by the bilinear interpolation algorithm is the average value of the processing results of by sliding window algorithm in four directions. In the edge region, the DoLP processed by sliding window algorithm is larger than bilinear interpolation algorithm. We apply the two algorithms are respectively applied to raw DoFP polarization images and evaluated by visual, statistical histogram, and mean value of the DoLP image. Experimental results prove that compared with bilinear interpolation algorithm, the sliding window algorithm produces stronger pseudo-DoLP information at edges, which highlights the details of the edges.