4 resultados para Analog-Digital System
em Dalarna University College Electronic Archive
Resumo:
I denna uppsats undersöks huruvida en lyssnare kan skilja på två ljudmixar som är mixade på samma sätt men summerade på olika sätt. Den ena summeras analogt och den andra digitalt. Om så är fallet, hur tycker lyssnaren att dessa skillnader yttrar sig? Som metod fick en testpanel i ett blindtest lyssna på två olika mixar, en rocklåt och en jazzlåt, som båda fanns i både analogt och digitalt summerade versioner. Dessa fick testsubjekten sedan besvara några frågor kring och tycka till om dessa olika versioner i en kvalitativ enkätundersökning Det visade sig att skillnader uppfattades av merparten av lyssnarna. Den vanligast förekommande beskrivningen var att det var skillnad på stereobredd, djup och dynamik i mixarna beroende på hur de summerats. Även ord som klarhet, värme och tydlighet förekom. Testpanelen var överlag även väldigt bra på att gissa vilken version som var summerad på vilket sätt. Dessa gissningar verkar i på många fall vara baserad på den förutfattade meningen att analogt borde vara bättre. Det är ganska tydligt att detta forskningsarbete i mångt och mycket är en fallstudie för just de variabler som förekom (märke på den analoga summeraren, ljudkvalité på de inspelade ljudet, programmaterial med mera). Fler tester och undersökningar behövs för att kunna dra generella slutsatser.
Resumo:
I denna uppsats undersöks skillnaden mellan EQ:s som analog hårdvara och dess digitala motsvarigheter, dvs. emuleringar i pluginformat. I uppsatsen undersöks enheterna genom tekniska mätningar samt lyssningstest. I mätningarna gick det att se tydliga skillnader i övertonsdistortionen även om resterande parametrar var bra emulerade. I lyssningstesten uppfattade lyssningspanelen relativt stora skillnader mellan enheterna. Detta visar på att emuleringarna inte är så bra och exakta som utvecklarna påstår.
Resumo:
The rapid development of data transfer through internet made it easier to send the data accurate and faster to the destination. There are many transmission media to transfer the data to destination like e-mails; at the same time it is may be easier to modify and misuse the valuable information through hacking. So, in order to transfer the data securely to the destination without any modifications, there are many approaches like cryptography and steganography. This paper deals with the image steganography as well as with the different security issues, general overview of cryptography, steganography and digital watermarking approaches. The problem of copyright violation of multimedia data has increased due to the enormous growth of computer networks that provides fast and error free transmission of any unauthorized duplicate and possibly manipulated copy of multimedia information. In order to be effective for copyright protection, digital watermark must be robust which are difficult to remove from the object in which they are embedded despite a variety of possible attacks. The message to be send safe and secure, we use watermarking. We use invisible watermarking to embed the message using LSB (Least Significant Bit) steganographic technique. The standard LSB technique embed the message in every pixel, but my contribution for this proposed watermarking, works with the hint for embedding the message only on the image edges alone. If the hacker knows that the system uses LSB technique also, it cannot decrypt correct message. To make my system robust and secure, we added cryptography algorithm as Vigenere square. Whereas the message is transmitted in cipher text and its added advantage to the proposed system. The standard Vigenere square algorithm works with either lower case or upper case. The proposed cryptography algorithm is Vigenere square with extension of numbers also. We can keep the crypto key with combination of characters and numbers. So by using these modifications and updating in this existing algorithm and combination of cryptography and steganography method we develop a secure and strong watermarking method. Performance of this watermarking scheme has been analyzed by evaluating the robustness of the algorithm with PSNR (Peak Signal to Noise Ratio) and MSE (Mean Square Error) against the quality of the image for large amount of data. While coming to see results of the proposed encryption, higher value of 89dB of PSNR with small value of MSE is 0.0017. Then it seems the proposed watermarking system is secure and robust for hiding secure information in any digital system, because this system collect the properties of both steganography and cryptography sciences.
Resumo:
This thesis is about new digital moving image recording technologies and how they augment the distribution of creativity and the flexibility in moving image production systems, but also impose constraints on how images flow through the production system. The central concept developed in this thesis is ‘creative space’ which links quality and efficiency in moving image production to time for creative work, capacity of digital tools, user skills and the constitution of digital moving image material. The empirical evidence of this thesis is primarily based on semi-structured interviews conducted with Swedish film and TV production representatives.This thesis highlights the importance of pre-production technical planning and proposes a design management support tool (MI-FLOW) as a way to leverage functional workflows that is a prerequisite for efficient and cost effective moving image production.