Data Model

The data model of Epina ImageLab is a four-dimensional hypercube, which is based on the following coordinates: x and y (spatial coordinates), layer (properties, wavelengths, wave numbers, masses, etc.), and time. This 4D hyper-cuboid can be seen as a series of 3D cuboids:

This means that each layer constitutes an image, which displays the corresponding property stored in this layer. The properties may represent any kind of information, from physical properties to spectral intensities at a particular wavelength. In fact, Epina ImageLab supports a plethora of various kinds of data. Thus images originating from different spectroscopic techniques can be combined into a single cuboid.

Although this general approach allows you to store and handle any number of spectra or other information, the number of allowed different spectra in a single cuboid is restricted to four. This restriction is simply due to practical reasons and mostly determined by limitations of the user interface.

In addition to up to four spectral domains, the cuboid can contain any number of layers representing more or less unrelated properties. For example, some of the layers may contain physical properties or information on detector sensitivities, etc.

The layers may be arbitrarily mixed as long as the spectral domains are contiguous. For example, the following figure (left part) shows three spectral domains (Infrared, MS, and Raman) and a bunch of individual property layers.

Each pixel of an image can be flagged by four numerical attributes (for details, see the Pixel Attributes section).

In addition to the data cube Epina ImageLab maintains up to 32 pixel masks which match the layers of the data cube and have the same spatial resolution as the data cube. Pixel masks are invariant over time and can be used to control which pixels are used in (or excluded from) certain image processing procedures. See the section on masking pixels for more.

The image repository can be used as an auxiliary storage area for image data. The repository data are displayed as images in the 2D Imager.

Finally Epina ImageLab supports a repository of spectra (see Spectral Collection for more). This repository may contain both spectra of particular pixels and mean spectra obtained from averaging the spectra of a user-defined region.