Design of false color palettes for grayscale reproduction

- Palettes with monotonic or linear luminance are the best for grayscale reproduction.
- A few sample palettes ready to use were proposed.
- Linear function and Lagrange polynomials can be used for interpolation.
- Lagrange interpolation formulas for 3 and 4-point palettes were shown.

Design of a false color palette is quite easy but some more effort is required to achieve a good dynamic range, contrast and overall appearance of the palette. Such palettes, for instance, are commonly used in scientific papers for data presentation. However, to lower the cost of the article, most scientists decide to let the data be printed in grayscale. The same applies to e-book readers based on e-ink most of which are still grayscale. For the majority of false color palettes reproduction in grayscale results in ambiguous mapping of the colors which may be misleading for the reader. In this article design of false color palettes, suitable for grayscale reproduction, is described. Due to the monotonic change of luminance of these palettes, grayscale representation is very similar to the data directly presented with a grayscale palette. Some suggestions and examples, of how to design such palettes, are provided. To compare the palettes and indicate the best one, a survey and numerical calculations were made.