Image Compression in Diffraction-limited Imaging Systems

Image compression for a class of imaging systems with optically-limited resolution is discussed. Particular area of interest is the case when the image resolution is limited by the aperture of lens, or so called diffraction-limited systems. Examples of diffraction-limited imaging systems are high-end pinhole cameras, high-resolution microscopy and telescopy. These systems require high quality of images, so in most cases perceived images are stored raw or compressed with lossless or near-lossless quality. Straightforward usage of image compression algorithms leads to low compression ratios due to presence of noise. In our work we show that compression ratio of these algorithms can be improved by preliminary filter without affecting image quality. This filter takes into account diffraction-limited spatial bandwidth of optics, so compressed image quality can be called "optically lossless". The filter can be applied before using image compression algorithms or can be integrated within compression procedure