A Testing Environment for Continuous Colormaps

TL;DR

This paper introduces a comprehensive test suite and web-based tool for evaluating and designing continuous colormaps in visualization, enabling systematic assessment of colormap effects on various data features.

Contribution

It establishes a standardized, extensible test suite and online platform for evaluating continuous colormaps, complementing traditional subjective and empirical evaluation methods.

Findings

Provides a systematic way to test colormaps on diverse data features

Includes a collection of real-world datasets for testing

Integrates into a web-based tool for colormap design and evaluation

Abstract

Many computer science disciplines (e.g., combinatorial optimization, natural language processing, and information retrieval) use standard or established test suites for evaluating algorithms. In visualization, similar approaches have been adopted in some areas (e.g., volume visualization), while user testimonies and empirical studies have been the dominant means of evaluation in most other areas, such as designing colormaps. In this paper, we propose to establish a test suite for evaluating the design of colormaps. With such a suite, the users can observe the effects when different continuous colormaps are applied to planar scalar fields that may exhibit various characteristic features, such as jumps, local extrema, ridge or valley lines, different distributions of scalar values, different gradients, different signal frequencies, different levels of noise, and so on. The suite also includes an expansible collection of real-world data sets including the most popular data for colormap testing in the visualization literature. The test suite has been integrated into a web-based application for creating continuous colormaps (https://ccctool.com/), facilitating close inter-operation between design and evaluation processes. This new facility complements traditional evaluation methods such as user testimonies and empirical studies.