Variable size block truncation coding with adaptive bit plane omission for image compression

A modified version of the Block Truncation Coding (BTC), which is a non-information preserving image compression technique, is studied. The first modification is the introduction of variable block sizes to the standard BTC technique. The second modification is the adaptive omission of bit planes. Threshold selections for this modified BTC technique are analyzed in the context of the human visual system. Modified BTC techniques are compared against the standard technique from the point of view of visual image quality and compresion efficiency

A User Oriented Image Retrieval System using Halftoning BBTC

The objective of this paper is to develop a system for content based image retrieval (CBIR) by accomplishing the benefits of low complexity Ordered Dither Block Truncation Coding based on half toning technique for the generation of image content descriptor. In the encoding step ODBTC compresses an image block into corresponding quantizes and bitmap image. Two image features are proposed to index an image namely co-occurrence features and bitmap patterns which are generated using ODBTC encoded data streams without performing the decoding process. The CCF and BPF of an image are simply derived from the two quantizes and bitmap respectively by including visual codebooks. The proposed system based on block truncation coding image retrieval method is not only convenient for an image compression but it also satisfy the demands of users by offering effective descriptor to index images in CBIR system

Emergent properties of the G1/S network

Tato práce se zabývá buněčným cyklem kvasinky Saccgaromyces cerevisiae. Oblastí našeho zájmu je přechod mezi G1 a S fází, kde je naším cílem identifikovat velikosti buňky v době počátku DNA replikace. Nejprve se věnujeme nedávno publikovanému matematickému modelu, který popisuje mechanismy vedoucí k S fázi. Práce poskytuje detailní popis tohoto modelu, stejně jako časový průběh některých důležitých proteinů či jejich sloučenin. Dále se zabýváme pravděpodobnostním modelem aktivace replikačních počátků DNA. Nově uvažujeme vliv šíření DNA replikace mezi sousedícími počátky a analyzujeme jeho důsledky. Poskytujeme také senzitivní analýzu kritické velikosti buňky vzhledem ke konstantám popisujícím dynamiku reakcí v modelu G1/S přechodu.In this thesis we deal with the cell cycle of the yeast Saccharomyces cerevisiae. We are interested in its G1 to S transition, and our main goal is to determine the cell size at the onset of its DNA replication. At first, we study a recent mathematical model describing the mechanisms leading to the S phase, we provide its detailed description and present the dynamics of some significant protein and protein complexes. Further, we take a closer look at the probabilistic model for firing of DNA replication origins. We newly consider the influence of DNA replication spreading among neighboring origins, and we analyze its consequences. We also provide a sensitivity analysis of the critical cell size with respect to rate constants of G1 to S transition model.

Data Embedding Using Block Truncation Coding

     في هذا البحث تم تقديم طريقة إخفاء البيانات التي تخفي البيانات في مجال الضغط. تستخدم طريقة ترميز اقتطاع الكتلة (BTC) لإخفاء المعلومات. النقطة الأساسية في الطريقة المقترحة هي أن يتم تطبيقها أولاً باستخدام ترميز اقتطاع الكتلة التقليدية ثم يتم تطبيقه لاحقًا باستخدام ترميز اقتطاع الكتلة المحسن(IBTC)  .تظهر النتائج التجريبية أن IBTC تمكن من اخفاء كمية كبيرة من البيانات في الملف المضغوط مع الحفاظ على جودة صورة مرضية.In this paper, a data hiding method is presented that hide the data in the compression domain. The Block Truncation Coding (BTC) method is used for hiding the information. The key point of the proposed method is to first apply traditional Block Truncation Coding and later it applied using Improved Block Truncation Coding (IBTC). Experimental results show that IBTC can embed a large amount of data in the compressed file while maintaining satisfactory image quality

Image coding using wavelet transform and adaptive block truncation coding

This thesis presents a new image coding using wavelet transform and adaptive block truncation coding. Images are first pre-processed by the wavelet transform and then coded by the adaptive block truncation coding. Algorithms for both monochrome and color images are proposed and experimentally studied. The adaptive block truncation coding is also modified to achieve better performance. For coding monochrome images at the bit-rate region between 0.8 to 1.2 bits/pixel, the performance of the new coding is comparable to the ones of subband codings and other image codings using the wavelet transform; however, the new coding offers less computational load. The new coding also gives a good reconstruction of a color image at the bit-rate of 1.0 bit/pixel. The comparison between the new coding and the original adaptive block truncation coding is also given. The discussion on effects of a filter and a number of decomposition levels used for an implementation of the wavelet transform is included in this thesis, as well

Data compression techniques applied to high resolution high frame rate video technology

An investigation is presented of video data compression applied to microgravity space experiments using High Resolution High Frame Rate Video Technology (HHVT). An extensive survey of methods of video data compression, described in the open literature, was conducted. The survey examines compression methods employing digital computing. The results of the survey are presented. They include a description of each method and assessment of image degradation and video data parameters. An assessment is made of present and near term future technology for implementation of video data compression in high speed imaging system. Results of the assessment are discussed and summarized. The results of a study of a baseline HHVT video system, and approaches for implementation of video data compression, are presented. Case studies of three microgravity experiments are presented and specific compression techniques and implementations are recommended

Hide text depending on the three channels of pixels in color images using the modified LSB algorithm

At the moment, with the great development of information and communications technology, the transfer of confidential and sensitive data through public communications such as the Internet is very difficult to keep them from hackers and attackers. Therefore, it is necessary to work on the development of new and innovative ways to transfer such information and protect it to ensure that it reaches the desired goal. The goal of a new technique to hide information design not only hides the secret message behind the center cover, but it also provides increased security. The most common way to transfer important and confidential data is through embedding it into cover medium files in a way that does not affect the accuracy of the carrier file, which is known as hiding. In this paper, encryption and concealment techniques were used to protect data transferred from attackers. The proposed method relied on encryption of confidential information using the encryption key and the Xnor gate, after which the encrypted information was hidden in a color image using the LSB algorithm. The method of concealment depends on the extraction of chromatic channels of three RGB for each pixel and specifying the channel in which the bit of the encryption message will be hidden. Some metrics have been adopted to measure the quality of the resulting picture after hiding as PSNR and MSE, and achieve good results