Improved Algorithm for ODCT Computation of a Running Data Sequence by S. Akhter, V. Karwal, R. C. Jain

“…Fast windowed update algorithms capable of independently updating the odd discrete cosine transform (ODCT) and odd discrete sine transform (ODST) of a running data sequence are analytically developed. …”
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Multiobjective Synthesis of Linear Arrays by Using an Improved Genetic Algorithm by Bo Yang

“…To reduce the computation complexity, the repeat calculation of the fitness function in each generation is replaced by a precomputed discrete cosine transform matrix. By transforming the array pattern synthesis into a multiobjective optimization problem, the conflict among the side lobe level (SLL), directivity, and nulls can be efficiently addressed. …”
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Just noticeable distortion model based on entropy masking in DCT domain by Qionghua LUO, Hongkui WANG, Haibing YIN, Yafen XING

“…In order to improve the threshold accuracy of JND (just noticeable distortion) model in DCT (discrete cosine transform) domain and avoid cross-domain operation, entropy masking effect was introduced into DCT-based JND model.Firstly, starting from the free-energy theory and the Bayesian inference, an autoregressive model based on texture-energy similarity in DCT domain was designed to simulate the spontaneous prediction behavior of visual perception.Secondly, the mapping relationship between visual perception and prediction residuals were explored to obtain the disorder intensity in block level.Thirdly, the entropy masking effect was modeled as a JND threshold modulation factor of disorder intensity.Finally, the JND model in DCT domain for the entropy masking was proposed by fusing the contrast sensitivity function, the luminance adaptive masking, the contrast masking.Compared with the existing JND model in DCT domain, the proposed model performed all operations in DCT domain, which was more efficient and concise.The subjective and objective experimental results indicate that the proposed JND model shows greater tolerance to distortion with better perceptual quality.…”
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Channel Estimation in DCT-Based OFDM by Yulin Wang, Gengxin Zhang, Zhidong Xie, Jing Hu

“…This paper derives the channel estimation of a discrete cosine transform- (DCT-) based orthogonal frequency-division multiplexing (OFDM) system over a frequency-selective multipath fading channel. …”
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Audio steganography by quantization index modulation in the DCT domain by CHEN Ming1, ZHANG Ru1, LIU Fan-fan1, NIU Xin-xin1, YANG Yi-xian1

“…A novel audio steganography based on QIM （quantization index modulation） in the DCT （discrete cosine transform） domain was proposed. The merits of the algorithm were as follows: based on the principle of QIM, the message was embedded by quantization method and was extracted by the map-ping between message bit and quantization interval. …”
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Design of an Efficient Real-Time Algorithm Using Reduced Feature Dimension for Recognition of Speed Limit Signs by Hanmin Cho, Seungwha Han, Sun-Young Hwang

“…Linear Discriminant Analysis (LDA) required for classification is performed by using Discrete Cosine Transform (DCT) coefficients. To reduce feature dimension in LDA, DCT coefficients are selected by a devised discriminant function derived from information obtained by training. …”
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Federated Learning Applications in Fingerprint and Finger Vein Recognition by Wang Yongchao

“…One of the frameworks for fingerprint recognition, Federated Learning-Fingerprint Recognition, uses sparse representation techniques such as the Discrete Cosine Transform for data preprocessing. The framework also references the ResNet18 model and reservoir sampling so that each client can participate in training fairly. …”
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A Novel Psychovisual Threshold on Large DCT for Image Compression by Nur Azman Abu, Ferda Ernawan

“…This research study proposes a psychovisual threshold on the large discrete cosine transform (DCT) image block which will be used to automatically generate the much needed quantization tables. …”
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A Packet Loss Concealment Technique Improving Quality of Service for Wideband Speech Coding in Wireless Sensor Networks by Nam In Park, Jin Ah Kang, Seong Ro Lee, Hong Kook Kim

“…It consists of three main functions: packet loss concealment in the narrowband, ABE in the modified discrete cosine transform (MDCT) domain, and smoothing of wideband MDCT coefficients with those of the last good frame. …”
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Assembly Accuracy Analysis Method Based on Multi‐Stage Linearized Contact by Wenbin Tang, Yadong Li, Tong Yan, Min Zhang

“…A model of part surface asperities considering morphological errors is established using the linear superposition of discrete cosine transform (DCT) kernel functions and the assembly interface is simplified. …”
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A New Highly Secure Optical Image Security Technique Using Gyrator Transform for Image Security-Related Applications by L. Anusree, M. Abdul Rahiman

“…Secret information hiding is performed in the Discrete Cosine Transform (DCT) domain to protect the data against noise attacks. …”
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Compressed Measurements Based Spectrum Sensing for Wideband Cognitive Radio Systems by Taha A. Khalaf, Mohammed Y. Abdelsadek, Mohammed Farrag

“…In this paper, we propose a novel compressed detector using energy detection technique on compressed measurements sensed by the discrete cosine transform (DCT) matrix. The proposed algorithm not only reduces the computational complexity but also provides a better performance than the traditional energy detector and the traditional compressed detector in terms of the receiver operating characteristics. …”
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JPEG reversible data hiding method based on optimal DCT frequency embedding by Ziyang ZHOU, Yun TAN, Jiaohua QIN, Xuyu XIANG

“…Joint photographic experts group (JPEG) images are widely used on the Internet due to their ability to maintain good picture quality while requiring less storage space.Reversible data hiding (RDH) techniques for JPEG images enable the hiding and extraction of secret information while allowing for lossless restoration of the original image.RDH is of great significance in file management and image authentication.However, many existing RDH methods result in a significant increase in the storage space of the encoded image after embedding secret information.For methods based on discrete cosine transform (DCT) coefficient embedding, the key issue that affects the performance of reversible information hiding in JPEG images is how to select the frequency band position.A reversible information hiding method for JPEG images was proposed, based on optimal DCT frequency embedding.The entropy decoded JPEG image was divided into 8×8 non-overlapping DCT blocks.The average texture complexity of each DCT block was calculated and ordered in ascending order.Then the alternating current (AC) in adjacent DCT blocks was paired pairwise.By satisfying the capacity of the information to be embedded, the optimal AC coefficient frequency position set was obtained from the distortion cost function of the AC coefficient frequency.The secret information was embedded according to the designed two-dimensional histogram mapping strategy.Experimental results demonstrate that the proposed method can reduce the expansion of the loaded image file’s storage size compared to existing methods, while maintaining good visual quality of the cover image.…”
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Enhancing Image-Based JPEG Compression: ML-Driven Quantization via DCT Feature Clustering by Shahrzad Sabzavi, Reza Ghaderi

“…The purpose of this research is to explore a novel approach that combines machine learning, discrete cosine transform (DCT) feature clustering, and genetic algorithms to customize image compression methods. …”
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A Multi-Scale Convolutional Residual Time-Frequency Calibration Method for Low-Accuracy Air Pollution Data by Jiahao Liu, Fei Shi, Zhenhong Jia, Jiwei Qin

“…Additionally, the Frequency Enhanced Channel Attention Mechanism (FECAM) uses Discrete Cosine Transform (DCT) to convert time-domain data to frequency-domain, assigning weights to different frequency components to enhance key features and suppress irrelevant ones. …”
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An autoencoder for compressing angle-resolved photoemission spectroscopy data by Steinn Ýmir Ágústsson, Mohammad Ahsanul Haque, Thi Tam Truong, Marco Bianchi, Nikita Klyuchnikov, Davide Mottin, Panagiotis Karras, Philip Hofmann

“…To test the data representation capacity of ARPESNet, we compare k -means clustering quality between data compressed by ARPESNet, data compressed by discrete cosine transform, and raw data, at different noise levels. …”
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Joint Source-Channel Coding for Multi-Channel Vibrotactile Sensors by Tom Ogura, Shogo Kitamura, Takuya Fujihashi, Shunsuke Saruwatari, Takashi Watanabe

“…The proposed coder compresses vibrotactile data using a two-dimensional discrete cosine transform (2D-DCT) without binarization, and the transmitter maps the DCT coefficients directly to transmission symbols. …”
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Asynchronous Realization of Algebraic Integer-Based 2D DCT Using Achronix Speedster SPD60 FPGA by Nilanka Rajapaksha, Amila Edirisuriya, Arjuna Madanayake, Renato J. Cintra, Dennis Onen, Ihab Amer, Vassil S. Dimitrov

“…Recently proposed algebraic-integer-(AI-) based discrete cosine transform (DCT) algorithms are analyzed in the presence of quantization, using the High Efficiency Video Coding (HEVC) standard. …”
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Robust medical zero‐watermarking algorithm based on Residual‐DenseNet by Cheng Gong, Jing Liu, Ming Gong, Jingbing Li, Uzair Aslam Bhatti, Jixin Ma

“…A Residual‐DenseNet is designed, which took low‐frequency features after discrete cosine transformation of medical images as labels and applied skip connections and a new objective function to strengthen and extract high‐level semantic features that can effectively distinguish different medical images and binarise them to get robust hash vectors. …”
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Perfectly blind image watermarking scheme with multi-purpose based on region segment for sub-block and self-embedding technology by Tian-yu YE

“…Finally, a watermarked image was obtained after conducting inverse discrete cosine transformation on each block. The proposed algorithm achieved perfectly blind detection and multi-purpose by combining self-embedding feature watermark from re-gion 1 into region 2 and blindly extracting authentication watermark n region 2. …”
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