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A multiple-image encryption method via lifting wavelet transform (LWT) and XOR operation is proposed, which is based on a row scanning compressive ghost imaging scheme. In the encryption process, the scrambling operation is implemented for the sparse images transformed by LWT, then the XOR operation is performed on the scrambled images, and the resulting XOR images are compressed in the row scanning compressive ghost imaging, through which the ciphertext images can be detected by bucket detector arrays. During decryption, the participant who possesses his/her correct key-group, can successfully reconstruct the corresponding plaintext image by measurement key regeneration, compression algorithm reconstruction, XOR operation, sparse images recovery, and inverse LWT (iLWT). Theoretical analysis and numerical simulations validate the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

• Considering the additional information from the degree of polarization (DoP), the polarimetric dehazing method is improved with the fusion of the intensity and the DoP. • The wavelet transform is exploited to make fusion, and different fusion rules are designed for the low-frequency and the high-frequency, respectively. • The introduction of DoP enriches the detailed information of the dehazed image, especially for the transparent object that is hard to be handled with previous methods. Image dehazing is an indispensable approach to address the image degeneration in hazy environment. In recent years, polarimetric methods have been widely investigated for image dehazing. In the basic algorithm of polarimetric dehazing, in addition to the dehazed intensity, the degree of polarization (DoP) can also be reconstructed with the assistance of Stokes parameters. Considering the additional information from the DoP, the polarimetric dehazing method is improved with the fusion of the intensity and the DoP. The wavelet transform is exploited to make fusion, and different fusion rules are designed for the low-frequency and the high-frequency components, respectively. The proposed method can improve the quality of polarimetric dehazed image, especially for the transparent object that is hard to be handled with previous methods. The validity of the proposed method is demonstrated in experiments. [ABSTRACT FROM AUTHOR]

• An optical color watermarking scheme based on single-pixel imaging and singular value decomposition in invariant wavelet domain is proposed. • Bayer array is introduced into full color single-pixel imaging and the amount of data needs to be stored is reduced to one third. • The construction of invariant wavelet domain and principle components embedding based on singular value decomposition provide our watermarking scheme higher robustness and security. A blind optical color watermark scheme is proposed with single-pixel imaging (SPI), redistributed invariant lifting wavelet transform (RILWT) and singular value decomposition (SVD), in which, the watermark is first encrypted by the SPI and then embedded into host image with SVD in redistributed invariant wavelet domain. Bayer array is introduced into SPI to complete full color imaging of target scene (watermark) and the amount of data needs to be stored is reduced to one third. The construction of RILWT and principle components embedding based on SVD provide our watermark scheme high robustness to various kinds of attacks. In addition, the watermark scheme has large capacity, good imperceptibility and no original host image is needed when extracting the watermark. The theory analysis and optical experimental results have demonstrated the good performance and high robustness of the proposed method. [ABSTRACT FROM AUTHOR]

Highlights • The optical image watermarking based on singular value decomposition ghost imaging and lifting wavelet transform is proposed. • It realizes good imperceptibility and robustness, and no original host image is needed when extracting the watermark. • Singular value decomposition ghost imaging has made the reconstruction process with less time and higher quality, and thus the reconstruction of the watermark image shows good performance. Abstract An optical image watermarking method based on singular value decomposition ghost imaging (SVDGI) and a blind watermarking algorithm is proposed. The watermark image is first encrypted by an SVDGI system, then the encrypted watermark is embedded in the host image with the help of the watermark algorithm, which uses the block discrete cosine transform (DCT) and integer lifting wavelet transform (LWT). The proposed watermarking algorithm has good imperceptibility and robustness, and no original host image is needed when extracting the watermark. SVDGI provides a new reconstruction method in ghost imaging (GI) by modifying the measurement matrix with the help of singular value decomposition, which carries out the reconstruction process in less time and at higher quality. The measurement matrix composes a secret key, and only with this key can authorized users decrypt and reconstruct the original watermark image. Both optical experiments and numerical simulations validate the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]

A multiple-image encryption method is proposed that is based on row scanning compressive ghost imaging, ( t , n ) threshold secret sharing, and phase retrieval in the Fresnel domain. In the encryption process, after wavelet transform and Arnold transform of the target image, the ciphertext matrix can be first detected using a bucket detector. Based on a ( t , n ) threshold secret sharing algorithm, the measurement key used in the row scanning compressive ghost imaging can be decomposed and shared into two pairs of sub-keys, which are then reconstructed using two phase-only mask (POM) keys with fixed pixel values, placed in the input plane and transform plane 2 of the phase retrieval scheme, respectively; and the other POM key in the transform plane 1 can be generated and updated by the iterative encoding of each plaintext image. In each iteration, the target image acts as the input amplitude constraint in the input plane. During decryption, each plaintext image possessing all the correct keys can be successfully decrypted by measurement key regeneration, compression algorithm reconstruction, inverse wavelet transformation, and Fresnel transformation. Theoretical analysis and numerical simulations both verify the feasibility of the proposed method. [ABSTRACT FROM AUTHOR]