This paper proposes an edge-directed interpolation algorithm for infrared images. At present, the resolution of infrared
focus planar array (IFPA) is relatively low. Conventional linear interpolation schemes such as the pixels replacement, the
bilinear interpolation and the bicubic interpolation result in blurred edges and zigzag pictures. The correlation of
different edge direction was calculated at each pixel to be interpolated to detect the edge and the edge direction. There
are 13 directions in two quadrants we have chosen. Most edge can be detected in this range. Pixels at the edge are
interpolated along the edge. The non-edge pixels are bilinearly interpolated. Simulation results show that the proposed
method effectively removed the zigzag and blur at the edge caused by conventional linear interpolation. And this method
is easy to be carried out by hardware.