Selection of a Suitable Color Palette

Using an appropriate color palette plays an important role in the process of visualization of image data. Epina ImageLab provides several predefined color palettes, which have been implemented to cover those color schemes most often used in image analysis. You can select a particular color palette by clicking the setup button in the 2D Imager. To change the default color palette used in the images (if not specified otherwise) please see the Preferences dialog for details.

In addition to the standard color palettes, Epina ImageLab supports the creation of user-defined color palettes (see Color Palette Editor for details). A few pre-configured user-definable color palettes are installed by default.

Among the standard palettes one particular palette is especially designed for people suffering from color perception deficiencies. This color palette (called "Morgenstemning") supports visualisation for people suffering from red-green blindness (keep in mind that about 10 percent of the male population suffers from color perception deficiencies).

Another aspect to be taken into account for the selection of color palettes concerns the use of colored images for superimposing photos (using the image stack). Especially, if parts of a gray scale photo are to be highlighted by colors, the predefined color palettes "mask_white_*" are helpful. For this purpose the colored image should be multiplied with the background photo at a blending level of 100% (the white areas won't change the photo background, while the colored regions show up in the gray scale image, see figure below).

The two images show an electron microscopic photo blended with the chlorine (green) and the sodium (pink) EDX signal. The palettes used for coloring the photo were "mask_white_green" and "mask_white_pink", multiplying the images with the gray scale background photo. The colored crystals are sodium chloride particles sampled in the vicinity of an Australian salt lake (data courtesy J. Ofner, Vienna University of Technology).

Hint: Sometimes it is convenient to assign a particular color palette to a spectral descriptor. This will automatically assign this color palette when the descriptor is displayed (overriding the default color setup). See Spectral Descriptors for details.