Strategies for efficient virtual microscopy in pathological samples using JPEG2000

This paper describes the design, implementation and validation of a new strategy for efficiently browsing large microscopical images (mega-images). A mega-image is constructed by registering a sequential set of microscopic fields of view, compressed and stored in hard disk using the JPEG2000 standard (J2K). Navigation is accelerated by fully exploiting J2K properties through the introduction of a cache strategy and an optimal delivering of quality information. Cache is introduced at the level of the spatial and resolution dimensions while optimal delivering is implemented on the organisation of minimal information units. Navigation with the conventional use of J2K results in extraction times of about 500 ms. We show that these strategies can improve navigation velocities up to a 30%, while we can efficiently represent high-quality and high-resolution colour images of microscopic specimens.