Raw data processing apparatus, raw data processing method and imaging device

Provided is a raw data processing apparatus including a variable processing part that processes raw data with a predetermined variable value, the raw data being output from an imaging element, an exposure determination part that receives the raw data and determines a gain value of the imaging element based on a determination result obtained by determining an exposure which is set when the raw data is shot, an improvement amount table in which an improvement amount for the gain value of the imaging element is set, a gain modulation part that extracts the improvement amount from the improvement amount table and modulates the gain value of the imaging element, a development parameter setting part that sets a development parameter used for developing the raw data, and a development processing part that outputs image data which is developed from the raw data processed with a predetermined variable value.