How does the Neuroinfo viewer display huge slide files so quickly?
Neuroinfo acts as an image server, with a Java-based slide viewer technology to serve ultra-high-resolution images rapidly and interactively on the Web. The viewer requests image data from the server one field of view at a time. As the viewer pans and zooms, additional tiles of the image are transferred. Virtual slides can be extremely large; file sizes of tens, even hundreds of megabytes, are impractical to download for viewing. The Neuroinfo technology stores these large images in a pyramidal file format, which stores multiple resolutions from the original source resolution of the microscope lens used for acquisition, down to a macro view of the entire slide or a thumbnail only a few kb in size. Each resolution level is cut into many small tiles. This enables navigating to any region of the slide at any magnification quickly.
