The second step of the image import has functionality for transforming the raw intensities of an image to either reflectance or pseudo-absorbance. Enabling spectral unit conversion is done by ticking the box at the top of the dialog. The user can then choose to convert the image to reflectance or absorbance. The user must also fill in the aquisition type. The following types exist:

- Line: Choose this type when the image has been acquired from a line scanning instrument. These instruments are sometimes referred to as push-broom instruments.
- Layer: Choose this type when the image has been acquired from an instrument that scans an entire layer (wavelength) at the same time. These instruments are sometimes referred to as focal plane scanning instruments, which can use an LCTF or AOTF for changing the measured wavelength.

The conversion is done with a two-point calibration using a set of two reference images. The user can browse any media for a dark (corresponding to 0% reflectance) and a white (corresponding to 100% reflectance) reference image. The user can alter the reflectance of the reference images in order to match the actual reflectance. The size (pixels) of the reference images for a line scanning instrument can have any number of lines. For a focal plane scanning instrument, the size in pixels must match the original sample image.

Checking the "Cap reflectance values higher than one unit" setting sets all values higher than the white reference to be equal to it.