Application of input amplitude masks in scheme of optical image encryption with spatially-incoherent illumination
Anna V. Shifrina, Nikolay N. Evtikhiev, Vitaly V Krasnov · Journal of Physics Conference Series · 2016
Optical encryption with spatially incoherent illumination does not have drawbacks of coherent encryption techniques. In this case however, one of the factors affecting decrypted image quality is original image spectrum. In most cases, majority of image energy is concentrated in area of low spatial frequencies. Therefore, only this area in spectrum of encrypted image contains information about original image, while other areas contain only noise. Additional amplitude encoding of input scene can be used for increase of the size of the area of spatial frequencies containing useful information. Numerical simulation demonstrates reduction of decryption error up to 2.7 times.