Color uniformity descriptor: An efficient contextual color representation for image indexing and retrieval.

•A Color Uniformity Descriptor (CUD) was designed for CBIR on heterogeneous sets.•CUD clusters similar color regions by analyzing the local color variations.•A thin histogram yields color details without compromising uniqueness and robustness.•CUD is computationally efficient with high precision and throughput rates in CBIR.•Due to generality/particularity balance, CUD is robust to strong content variation.