Image and Video Compression

Penelitian ini bertujuan untuk mengevaluasi performa beberapa algoritma kompresi data dalam kaitannya dengan efisiensi penyimpanan dan kecepatan transfer data. Fokus utama terletak pada perbandingan antara efisiensi hasil kompresi, durasi proses kompresi-dekompresi, serta dampaknya terhadap waktu pengiriman data. Untuk mendukung analisis, digunakan teori dasar dari teknik kompresi seperti algoritma JPEG, Discrete Cosine Transform (DCT), dan Huffman Coding yang sering digunakan dalam pengolahan gambar digital.Data diperoleh melalui uji coba terhadap berbagai jenis file gambar digital (JPG, TIFF, GIF), kemudian dianalisis secara kualitatif dengan meninjau rasio kompresi, durasi proses, serta pengaruh karakteristik data terhadap efektivitas kompresi. Hasil analisis menunjukkan bahwa pemilihan algoritma yang sesuai (contohnya, adaptasi JPEG pada file non-JPG) dapat meningkatkan efisiensi ruang simpan hingga 40% dan mempercepat pengiriman data. Namun, efektivitas setiap algoritma sangat bergantung pada tingkat redundansi dan jenis format file yang digunakan.

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Discrete cosine transform (DCT) is widely used in image and video compression standards. This paper presents distributed arithmetic (DA) based VLSI architecture of DCT for low hardware circuit cost as well as low power consumption. Low hardware cost is achieved by exploiting redundant computational units in recent literature. A technique to reduce error introduced by sign extension is also presented. The proposed 1-D DCT architecture is implemented in both the Xilinx FPGA and Synopsys DC using TSMC CLN65GPLUS 65nm technology library. For power and hardware cost comparisons, recent DA based DCT architecture is also implemented. The comparison results indicate the considerable power as well as hardware savings in presented architecture. 2-D DCT is implemented using row column decomposition by the proposed 1-D DCT architecture.

In this paper, an efficient orthogonal sparse 8×8 transform matrix for low bit-rate image compression is proposed. The transform matrix is made sparse by appropriately inserting additional zeros into the matrix proposed by Bouguezel. The algorithm for fast computation is also developed. It is shown that the proposed transform matrix provides a 20% reduction in computation over the matrix proposed by Bouguezel, and 45% over signed discrete cosine transform (SDCT). By using various test images, it is shown that the rate-distortion performance is also almost comparable to that of above two transform matrices at low bit-rates. Keywords─ Signed discrete cosine transform (SDCT), Image compression, Percentage error energy norm (PEEN).

Discrete cosine transform (DCT) is usually used in JPEG based image transform coding. This paper presents separable 2-D discrete Hartley transform (SDHT) and its Distributed Arithmetic (DA) based hardware architecture as an alternate to DCT in transform based coding of image compression. The proposed DA architecture for 1-D DHT has very less computations as compared to existing 1-D DCT. The proposed DHT architecture implemented in FPGA indicates a significant hardware savings as compared to FPGA resources used in an efficient memory based DA approach. The additional advantage of SDHT is that its inverse transform is same as forward transform with a constant division. This is demonstrated through a Xilinx FPGA XC2VP30 device.

Penilaian komunikasi nonverbal dapat diterapkan pada rekrutmen keja secara online. Pemanfaatan aplikasi rekrutmen mulai dipergunakakan beberapa perusahaan swasta untuk efisiensi waktu dan biaya. Untuk mengetahui konsistensi antara ekspresi emosional dengan gerakan wajah diperlukan skill biasanya ditangani seorang psikiologis. Dalam penelitian ini data set berbentuk frame dari video pelamar kerja dilakukan penilaian komunikasi nonverbal yang fokus pada gerakan mata, mulut dan wajah. Formula dan filter GLCM diterapkan untuk ekstraksi ciri bertujuan menemukan pola berdasarkan distribusi statistik dan intensitas piksel. Ekstraksi komunikasi nonverbal bertujuan menganalisa pola gerakan wajah. Formula ektraksi ciri terdiri dari feature, contras, energi, entropy dan homogenitas. Filter ekstraksi dirotasi pada sudut 00, sudut 450, sudut 900, dan sudut 1350. Sumber data 10 video, diambil 10 frame bagian wajah, mata dan mulut per video untuk diekstrak dan dianalisa. Berdasarkan perhitungan fo...

H IGH BIT DEPTH data acquisition and manipulation have been largely studied at the academic level in the last 15 years and are rapidly attracting interest at the industrial level. An example of the high interest for High Dynamic Range (HDR) imaging is the use of 32-bit floating point data for video and image acquisition and manipulation that allows a variety of visual effects that closely mimic the real world visual experience of the end-user [1] (see Fig. for an illustration). At industrial level, we are witnessing increasing traction towards supporting HDR and Wide Color Gamut (WCG). WCG leverages HDR for each color channel to display a wider range of colors. Consumer cameras are currently available with 14 or 16 bit A/D converter. Rendering devices are also appearing with the capability to display HDR images and video with a peak brightness of up to 4000 nits and to support wide color gamut (ITU-R Rec. BT.2020 [2]) rather than the historical ITU-R Rec. BT.709 [3]. This trend calls for a widely accepted standard for higher bit depth support that can be seamlessly integrated into existing products and applications. While standard formats such as JPEG 2000 [5] and JPEG XR [6] offer support for high bit depth image representations, their adoption requires a non-negligible investment that may not always be affordable in existing imaging ecosystems, and induces a difficult transition, as they are not backwardcompatible with the popular JPEG image format. Instead, most digital camera and mobile phone manufacturers either store images in proprietary RAW formats or, more commonly, offer an HDR mode, which produces a traditional low dynamic range image with improved details. The former solution creates a vendor lock-in problem for consumers, making it difficult to efficiently use images produced by such A.

L’intreccio tra spazio e suono è da sempre un terreno esperienziale ma anche oggetto di studi e di prassi, come in quelli di architettura e di musica.
A partire dalle avanguardie novecentesche e ancor più grazie alle possibilità introdotte dai nuovi strumenti tecnologici, il rapporto tra spazio e suono oggi costituisce un tema di ricerca davvero fecondo, capace di sviluppare il dialogo disciplinare tra diverse forme d’arte. Ne sono testimonianza i nuovi linguaggi in ambito musicale e architettonico, ma anche le ricerche teoriche e filosofiche intorno a concetti quali atmosfere, ambienti e paesaggi sonori.
Come scrive Giovanni Piana, la spazialità musicale può essere intesa in primo luogo in senso letterale e fisico, quando il suono si situa, si estende, si muove in un corpo sonoro e in un ambiente. In secondo luogo la spazialità musicale acquisisce un significato metaforico, là dove parametri come altezza, intensità e timbro possono essere intenzionati da chi ascolta in senso spaziale attraverso il lavoro dell’immaginazione o l’interazione sinestetica dei sensi.
Particolarmente significativa in questa prospettiva è la ricerca di Luigi Nono che ha fatto dello spazio uno degli ambiti principali della sua riflessione compositiva. Dagli esordi fino alla composizione per l’amico architetto Carlo Scarpa e a Das Atmende Klarsein degli anni ’80, Nono sembra svolgere le due accezioni di spazio sonoro descritte da Piana, per poi giungere a Prometeo. Tragedia d’ascolto, in cui l’elettronica dal vivo permette di valorizzare ulteriormente la potenzialità spaziale del fenomeno sonoro. La collaborazione con Massimo Cacciari e Renzo Piano su questo ultimo progetto, inoltre, dà l’idea di quanto feconda sia una riflessione aperta all’interazione con più discipline.
A questa articolazione teorica e pratica si affianca, in anni più recenti, il contributo dei media studies, che hanno messo in luce il ruolo di strumenti di registrazione, riproduzione e spazializzazione del suono nella ridefinizione della percezione spaziale. L’analisi di differenti dispositivi ha permesso di esplorare come le tecnologie sonore non solo fungano da mediatori, ma contribuiscano attivamente a generare ambienti acustici, influenzando in profondità la nostra esperienza dello spazio. Le installazioni sonore interattive e le esperienze acustiche situate dimostrano come i media siano oggi attori centrali nella costruzione di nuove forme di spazialità sensibile e simbolica, favorendo un dialogo sempre più stretto tra estetica, tecnologia e percezione.
La spazialità sonora si rivela dunque angolo prospettico essenziale per osservare e svolgere l’intricata stratificazione di senso della costituzione sia dell’intero sonoro sia del volume architettonico.

Le due giornate di studio, sostenute dal Dipartimento di Filosofia “Piero Martinetti” dell’Università degli Studi di Milano e dalla Società Italiana di Estetica, con il patrocinio intellettuale della Fondazione Luigi Nono e di Milano Musica, in collaborazione con la Fondazione Culturale San Fedele e con Triennale Milano, intendono mettere a tema le potenzialità filosofiche, musicali, compositive e architettoniche del suono considerato nella sua dimensione spaziale, suscitando il dibattito attuale ed esplorando gli orizzonti di senso e le potenzialità del nesso secolare spazio-musica, anche attraverso il confronto tra giovani ricercatori e studiosi affermati, provenienti da diverse sedi universitarie italiane.

Ce papier traite du problème de codage vidéo de forme avec perte. Ce problème appartient au domaine du codage vidéo basé objets. Notre approche propose d'exploiter la corrélation spatio-temporelle, en considérant l'évolution du contour et en traitant le phénomène d'occultation. La nouveauté réside dans une mise en correspondance fine des contours ainsi que dans le prolongement des parties occultées. Une fois que les contours sont traités, une transformation ondelette avec un schéma IPB est utilisée pour les encoder. Les résultats expérimentaux montrent une amélioration significative à très faible débit. De plus, le train binaire est totalement progressif.

Puji syukur ke hadirat Tuhan Yang Maha Esa, yang telah
memberikan rahmat dan karunia-Nya sehingga buku ini dapat
terselesaikan dengan baik. Buku ini berjudul "Pemahaman dan
Penilaian Keaslian Dokumen dengan Ekstraksi Fitur Tekstur dan
Ciri Visual", yang bertujuan untuk memberikan pemahaman
mendalam mengenai proses verifikasi keaslian dokumen melalui
berbagai teknik analisis, termasuk ekstraksi fitur tekstur dan ciri
visual. Buku ini dirancang untuk memberikan wawasan kepada para
profesional, akademisi, dan praktisi yang bekerja di bidang keamanan
dokumen, forensik, dan teknologi digital.
Melalui buku ini, pembaca akan diperkenalkan dengan berbagai
metode canggih yang digunakan untuk memverifikasi keaslian
dokumen fisik maupun digital, serta tantangan yang dihadapi dalam
menghadapi pemalsuan dokumen yang semakin kompleks.
Diharapkan, buku ini dapat menjadi referensi yang bermanfaat dalam
pengembangan teknologi dan pendekatan yang lebih akurat dalam
memverifikasi keaslian dokumen di berbagai sektor, termasuk hukum,
bisnis, dan keamanan. Semoga buku ini memberikan kontribusi positif
bagi kemajuan ilmu pengetahuan dan teknologi di bidang tersebut.

Blosc2 is a high-performance compression library and data format designed for binary data such as numerical arrays, tensors, and other structured types. In this proposal, we aim to develop two new codecs for Blosc2 by leveraging its extensible pluginbased codec framework. Specifically, we propose integrating archetypal analysis (AA) and fuzzy clustering as novel codecs within Blosc2. Our proposal has been assessed by using the Olivetti faces dataset and results have demonstrated that AA outperforms fuzzy clustering in preserving fine-grained data details, achieving substantially higher Structural Similarity Index. These results underscore AA's capability to capture the complete data distribution, including its extreme values, which is an essential property for achieving high-fidelity compression.

Online transactions through Online cards has more increased. As Online card becomes the most popular mode of payment for both online and offline, cases of fraud associated with it are also rising. In this paper, we model the sequence of operations in Online card transaction processing using a Hidden Markov Model (HMM) and show how it can be used to the detection of frauds. An HMM is initially trained with the normal behavior of a cardholder. If an incoming Online card transaction is not accepted by the trained HMM with sufficiently high probability, it is considered to be fraudulent. At the same time, we will attempt to guarantee that fraud transactions are rejected. We will present detail experimental results to show of our approach and will compare it with other techniques available in the literature Keywords: Internet; online shopping; credit card; e-commerce security fraud detection; Hidden Markov Model.

Image compression is an essential technique for saving time and storage space for the gigantic amount of data generated by images. This paper introduces an adaptive source-mapping scheme that greatly improves bit-level lossless grayscale image compression. In the proposed mapping scheme, the frequency of occurrence of each symbol in the original image is computed. According to their corresponding frequencies, these symbols are sorted in descending order. Based on this order, each symbol is replaced by an 8-bit weighted fixed-length code. This replacement will generate an equivalent binary source with an increased length of successive identical symbols (0s or 1s). Different experiments using Lempel-Ziv lossless image compression algorithms have been conducted on the generated binary source. Results show that the newly proposed mapping scheme achieves some dramatic improvements in regards to compression ratios.

This paper presents a compression framework for light-field images. The main idea of our approach is exploiting the similarity across sub-aperture images extracted from light-field data to improve encoding performance. For this purpose we propose a variational optimisation approach to estimate the disparity map from light-field images and then apply it to a motion-compensated wavelet lifting scheme. Making use of JPEG2000 for coding all high-/low-pass sub-band views as well as disparity map, our approach can therefore support both lossless and lossy compression. The coding framework is tested with both synthetic and real-world light-field dataset. The experimental results demonstrate that our approach outperforms JPEG-LS and the direct application of JPEG2000 in both lossless and lossy compression scenarios.

Abstract: Scalable video coding (SVC) is the extension of H. 264/AVC standard. The features in SVC are also developed from the H. 264/AVC standard, so that SVC has more features compared to H. 264/AVC standard. This provides higher coding complexity in SVC encoder which causes higher encoding time for SVC. SVC is gaining great interest because of its ability and scalability to adapt in various network conditions. SVC allows partial transmission and decoding of a bitstream. This research deals with multilayers fast mode decision ...

Scalable video coding (SVC) is classified as layered video codec which is the extension of H. 264/AVC standard [I, 2]. SVC based layered video coding is suitable for different usecases and different bitstream eg, supporting heterogeneous devices with a single, scalable bitstream. Such a stream allows for delivering a decode-able and presentable quality of the video depending on the device capabilities. In terms of spatiotemporal and quality, scalability of SVC is referred as a functionality that allows the removal of par1s of ...

Fig. . Our approach takes as input a grayscale image and a set of colored pixels picked out from a source color image (left). Pixels in the grayscale image are mapped to a feature space producing high-dimensional data instances which are projected to a visual space using an interactive multidimensional projection method (middle left). User can then interact with projected data so as to untangle clusters (middle right) and thus improving colorization result (right).