An optical coherence tomographic device may include: a light source； a measurement light generator that generates measurement light and generates reflected light from a target region in a scattering sample by irradiating the target region with the measurement light； a reference light generator that generates reference light； an interference light generator that generates interference light by combining the reflected light and the reference light； an interference light detector that detects the interference light and generates interference signals by converting the interference light； and a processor. The processor may cause the OCT device to execute: acquiring tomographic images for a same cross section in the target region in time series from the interference signals； calculating an entropy of the generated interference signals based on the tomographic images； and specifying a dynamic part in the tomographic images based on the calculated entropy.
