All of the approaches mentioned above require a method of file access that permits the software to readily load arbitrary blocks of data from the file which not all files allow. To this end, arivis developed what we call arivis ImageCore. ImageCore is a combination of a file format that enables arbitrary access to any part of the file, and the libraries implemented in the software that allows us to make use of this feature. Because this is central to the way arivis solutions operate it also means that we do not *open* files such as TIFF, PNG, or any of the common microscopy imaging formats (CZI, LIF, OIF, ND2, etc), but instead we import the data contained in those files into a new file capable of storing all the information and make it accessible in a way that makes it readily accessible to our software.

The files that arivis creates use the ".SIS" extension. SIS files are multidimensional-redundancy free-pyramidal file structures with lossless compression support. This means that:

• We can load the resolution that we need to display the images as and when we need them without needing huge amounts of RAM
• We do so without adding a lot of redundant data to handle the different zoom levels, keeping the imported file size relatively small
• We can handle images of virtually infinite sizes in a range of dimensions. SIS files support virtually limitless numbers of channels, planes, time points, and tiles of any width and height. The only real limit is the size of the storage in your computer. SIS files are technically 7-dimensional, where each pixel can be anything from 8-bit to 32-bit floating-point, and each pixel belongs to a specific X, Y, and Z location in a specific channel, time point, and image set. 
• With lossless compression, we can further reduce the size of the imported file by 20-80% depending on the image data.