36,890 research outputs found
Image compression using Huffman Coding algorithm
No full textCilj rada je opisati teorijske osnove kompresije slika i kompresije Huffman Coding algoritmom, a nakon toga implementirati Huffman Coding algoritam za kompresiju slika. Nakon objašnjene teorijske osnove kompresije i Huffman Coding algoritma uz primjer, kod implementiranog algoritma slijedi iste korake kao i prikazani primjer te je objašnjen istim redom. Algoritam je implementiram u Python programskom jeziku, a za dohvaćanje vrijednosti iz slike korištena je biblioteka OpenCV. Zapis u tekstualnu datoteku se odvija u dva koraka, prvo se zapisuju informacije o dimenzijama i informacije iz Huffmanovog stabla, a nakon toga slijed bitova koji nosi informacije slike i zapisan je pomoću bitarray biblioteke. Izvorna slika se može rekonstruirati iz tekstualne datoteke u koju je kompresija zapisana kao dokaz ispravne kompresije.The aim of the paper is to describe the theoretical foundations of image compression and compression by Huffman Coding algorithm followed by the implementation of the Huffman Coding algorithm for image compression. After explaining the theoretical foundations of compression and the Huffman Coding algorithm with a simple, the implemented algorithm follows the same steps as the presented example and is explained in the same order. Algorithm is implemented in the Python programming language and the OpenCV library was used to retrieve the values from the image. Writing to the text file takes two steps, first the dimension information and information from the Huffman tree are written, followed by the bit sequence that carries the image information and is written using the bitarray library. The original image can be reconstructed from text file in which the compression is written as proof of correct compression
Huffman coding application
No full textU ovom završnom radu kreirana je iOS mobilna aplikacija za Huffmanovo kodiranje. Objašnjen je Huffmanov algoritam i alati koji se koriste za izradu aplikacije. Problem s kojim se susreće je pretvaranje koraka Huffmanovog algoritma u njihov ekvivalent u kodu i rješenje koje se nudi dano je u dva dijela. Prvi dio implementacije zadužen je za izradu Huffmanovog stabla koje u programu izgleda drugačije od običnog stabla, ali ima istu funkciju. Drugi dio zadužen je za prolazak i čitanje stabla i to je postignuto rekurzivnom funkcijom. Veliku ulogu u ostvarenju rješenja ovog problema ima mogućnost programskog jezika Swift da koristi tip podatka „Any“ koji u potpunosti mijenja ulogu pokazivača. Cijeli proces sakriven je iza jednostavnog korisničkog sučelja koje omogućava korisniku upisivanje znakova koje želi kodirati i njihovo kodiranje pritiskom samo jednog dugmeta.In this bachelor's thesis an iOS mobile application was created. The Huffman algorithm and the tools used to create the application were explained. The problem encountered is transforming the steps of the Huffman algorithm into their equivalent in code and the answer offered is given in two parts. The first part of the implementation is in charge of creating the Huffman tree which looks different in the program than the usual tree but has the same functionality. The second part of the implementation is in charge of going through and reading from the tree and that was accomplished with a recursive function. A great part in achieving the goal of solving this problem was the possibility of the programming language Swift to use the data type “Any” which completely replaced the role of pointers. The whole process was hidden behind a simple user interface which allows the user to enter the characters he wants to encode and then encodes them with the press of a button
Comparison of Huffman and Arithmetic Coding in Image Compression
No full textCilj rada je usporedba dva najpoznatija algoritma za entropijsko kodiranje, Huffmanovog i aritmetičkog. Točnije, usporedba je temeljena na tome koji od ta dva algoritma je bolji kod kompresije slike u JPEG formatu. Sukladno tome, ukratko je opisan način rada JPEG-a te uloga Huffmanovog i aritmetičkog algoritma u tom postupku. Huffmanov i aritmetički algoritam su opisani tekstualno, dijagramom toka, jednostavnim primjerom i izvedbom u programskom jeziku Python, a zatim su primijenjeni nad konkretnim podacima koji nastaju pri kompresiji slike neposredno prije entropijskog kodiranja. Parametri prema kojima se provodila usporedba jesu stupanj kompresije i složenost algoritama. Na temelju tih podataka i rezultata dobivenih testiranjem algoritama, zaključeno je da je aritmetički algoritam pogodniji u postupku kompresije slike od Huffmanovog algoritma.The object of this paper is to compare the two most known algorithms for entropy coding, Huffman and arithmetic. In more particular, comparison is obtained between these two algorithms in order to prove which one is more apropriate for image compression in JPEG format. Accordingly, the JPEG and the part of Huffman and arithmetic algorithm in its process are briefly described. Descriptions of algorithms are performed by using text, flow chart, simple example and execution in the Python programming language, and then applied to the real life data generated by the step which leads entropy coding in image compression. The comparative parameters of algorithms are the compression ratio and the complexity of the algorithms. Based on these data and testing results, conclusion is made that arithmetic algorithm is more useful than Huffman algorithm in the image compression process
Woud: Trek je even terug in je concentratiebubbel
No full textHet was zo’n zonnige lentedag; heerlijk om lekker buiten te zijn. Ik zat binnen, in een vergadering – met de nodige moeite om mijn aandacht erbij te houden. Liever keek ik door het raam naar kersenbloesems. Afgeleid raken, wegdromen ofjuist onrustig zijn en niet stil kunnen zitten. Herkenbaar? Vast wel; iedereen heeft wel eens moeite om zich te concentreren. Maar voor sommige kinderen is dit een dagelijkse worsteling. Hoe ga je daar op een goede manier mee om in eenklaslokaal, een omgeving met constante prikkels en afleiding? Ontwerper Shion Ito ontwierp een mini-bos waar je je even in kunt terugtrekken om je rust terug te vindenGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Human-Centered DesignDesign Aesthetic
Data compression using Huffman coding
No full textVsebina tega dela predstavlja del področja stiskanja podatkov. Cilj je raziskati področje in se s praktičnim delom približati obstoječim rešitvam in s tem odgovoriti na vprašanja, ki bi se lahko pojavila v povezavi s področjem. Pred samo implementacijo je kratek vpogled v teoretično ozadje področja, iz katerega je potem rešitev izpeljana. Glavna tema v besedilu je algoritem Huffmanovo kodiranje, algoritem iz družine Lempel-Ziv pa je predstavljen in uporabljen za primerjavo dveh algoritmov z enakim končnim ciljem, ki pa ga dosegata na drugačen način. Predstavljeno je njuno delovanje in izvedena je primerjava učinkovitosti.
Za lažjo in uporabniku bolj prijazno uporabo je razvit tudi grafični vmesnik.The content of this thesis describes a part of the data compression field. The goal is to examine and imitate existing solutions and with that answer possible questions regarding data compression. Before we dive into details of implementation, we take a look at the theory behind it. Main topic is the Huffman`s algorithm and algorithm from a Lempel-Ziv family which is explained and used as a comparison of the two algorithms that have the same goal but are achieving it with different techniques. Their operation is briefly explained and a comparative study between the two is performed
Lossless Image Compression Using Huffman Coding
No full textCilj rada je proučiti postojeće metode i formate koji se koriste za kompresiju slika bez gubitaka podataka uz korištenje Huffmanovog kodera, te predložiti novi algoritam za istu. Predloženi algoritam temelji se na arbitrarnom obliasku piksela u slici i baziran je na A* algoritmu, te je implementiran u programskom jeziku Python 3. Stopa kompresije opisanog algoritma je u prosjeku 0 - 10 % bolja u odnosu na format PNG i ovisi o karakteristikama slike kao što su količina finih detalja i šuma u slici.The goal of the paper is to investigate methods and formats used for lossless image compression based on Huffman coding, and to propose a new approach to the aforementioned problem. The proposed algorithm, based on arbitrary order of pixel traversal, is built on top of the A* algorithm and is implemented in Python 3 programming language. The proposed algorithm has compression rate that is on average 0-10% better than the PNG equivalent and depends on image characteristics such as detail and noise levels
Londen laat zien: verstedelijking kun je privaat bekostigen
No full textSimon van Zoest en Tom Daamen doen bij de leerstoel Gebiedsontwikkeling onderzoek naar de financiering en bekostiging van grootstedelijk openbaar vervoer. Zij kijken daarbij voorbij de instrumenten en verdiept zich in de motieven en succesfactoren achter de invoer van alternatieve bekostiging. Zo maakt Londen duidelijk dat een private bijdrage aan ov-investeringen mogelijk én wenselijk kan zijnPractice Chair Urban Area DevelopmentUrban Development Managemen
Tam Tam in je broekzak
No full textDit is het eindverslag van de stage "Tam Tam in je broekzak", die wij hebben uitgevoerd in het kader van IN3405 Bachelorproject. Deze stage is uitgevoerd bij Tam Tam B.V. te Rijswijk.Technische InformaticaComputer ScienceElectrical Engineering, Mathematics and Computer Scienc
Melk in je koffie: Een onderzoek met mogelijkheden
No full textIn 1999 stond in de NRC een column van Karel Knip over de vraag uit de wetenschapsquiz of je direct een wolkje melk in je koffie moet doen als de bel gaat of dat je dat beter kunt doen als je terugkomt van de buitendeur. De column geeft een mooi beeld van wat er allemaal kan komen kijken als je wat dieper op de vraag ingaat. Er blijken veel mogelijkheden te zijn om ook in de klas met deze vraag aan de slag te gaan!ImPhys/Docente
Zo meet je de waarde van sociale investeringen
No full textWat leveren investeringen in de zachte, sociale kant van gebiedsontwikkeling op? Deze vraag houdt ontwikkelaars, gemeenten en beleggers al langer bezig. Een antwoord is te vinden via de capability-benadering. Hierbij staan niet de kwantitatieve fysieke functies centraal, maar de kwalitatieve mate waarin mensen in staat zijn deze te gebruiken.Practice Chair Urban Area Developmen
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