Research Article

A Novel Two-Stage Illumination Estimation Framework for Expression Recognition

Table 1

Comparison of different features.

FeatureDimensionAccuracyDescription

Saltire-over-cross feature282596.27The downsampled saltire-over-cross feature.
Saltire-over-cross feature564996.94The original saltire-over-cross feature.
Regional feature285694.47Select pixels of the whole facial region as feature, and resample the feature vector to 2856-dimension.
Regional feature582094.95Select pixels of the whole facial region as feature, and resample the feature vector to 5820-dimension.
Partitioned histogram1152089.78Partition the whole facial region into some blocks, extract histogram from each block, and concatenate all histograms to form a feature vector.