Subtraction Method for Subpixel Stitching: Synthetic Aperture Holographic Imaging

Image stitching is a crucial technique in various fields of imaging and photography, which allows for the creation of high-resolution images by combining multiple smaller images with overlapping regions. Here, we propose a simple and fast method, the Subtraction Method (SM), for pixel and subpixel image stitching using holographic data. The feasibility of the SM is verified at the pixel and subpixel level using two 2D images captured by a 4-f imaging system. Additionally, the application of the SM for holographic data is also explored. The effective aperture of an inline holographic imaging system is enlarged by stitching four in-line holograms, demonstrating enhanced resolution and image quality after reconstruction. The stitching accuracy and computational time of the SM is compared with the correlation method. With optimization, the result shows that the SM achieves high accuracy and requires less computational time for image stitching when compared to contemporary image stitching algorithms.