2.6. Image and cube generic products

2.6.1. SimpleImage product

The SimpleImage product contains a standard two-dimensional image, in particular the following arrays:

  • Image in an array 2D (e.g. double, integer)

  • (Optional) Error in an array 2D (e.g. double, integer)

  • (Optional) Exposure in an array 2D (e.g. double, integer)

  • (Optional) Coverage in an array 2D (e.g. double, integer)

  • (Optional) Flag in a short integer array 2D

It also contains metadata that provide unit and World Coordinate System information.

For further details see the User's Reference Manual: Section 1.384, “SimpleImage”.

2.6.2. SimpleCube product

The SimpleCube product allows us to store three-dimensional images (or multiple stacked 2D images). In particular it contains the following arrays:

  • Image in an array 3D (e.g. double, integer)

  • (Optional) Error in an array 3D (e.g. double, integer)

  • (Optional) Exposure in an array 3D (e.g. double, integer)

  • (Optional) Coverage in an array 3D (e.g. double, integer)

  • (Optional) Flag in a short integer 3D array

SimpleCube has the depth as the first (most slowly varying) index. It also contains metadata that provide unit and World Coordinate System information. A single WCS only can be applied to the SimpleCube. For example, it is not possible to provide different WCS sets for each image in an image stack.

For further details see the User's Reference Manual: Section 1.381, “SimpleCube”.

2.6.3. SpectralSimpleCube product

Conceptually, a spectral cube can be seen in three ways:

  • As a stack of monochromatic images

  • As a cloud of points, when at least one of the axes is not regularly sampled

  • As a set of spatially related spectra

SpectralSimpleCube can contain [1D, 2D] and 3D ArrayDatasets. The 3D sets store spectral stacks of images with dimensions [x3,x2,x1], where x3 is the spectral index. 2D sets are of dimension [x2,x1] and are interpreted as images. 1D sets are of dimension [x3] and are interpreted as spectra. SpectralSimpleCube also contains metadata information that provide unit and World Coordinate System information.

SpectralSimpleCube is an extension of the SimpleCube product. As such it includes all its features, such as the error and exposure maps seen before. The main difference is that reading an (x, y) position in a SpectralSimpleCube will return a Spectrum1d, while doing the same with a SimpleCube will return a generic one-dimensional array of flux values.