A real-time fingerprintidentification system using binary joint transform correlator with a single space lightmodulator and a single CCD has been developed successfully. A discrete cosine transformalgorithm was used to process the joint power spectrum in order to enhance thecross-correlator term and eliminate the auto-correlator term in the joint power spectrumand improve the discriminability of the system.The light energy passing through the systemwas controlled by adjusting the gray-value range of the space light modulator at Fourierplane, as a result the system could execute real-time fingerprint identification. A newtwo-parameter decision method was used to decide the correlator signal, and the decidingveracity was improved. Real-time tests yielded a false rejection rate of 0.47% and a falseacceptance rate of zero.