Document Image Retrieval Based On Layout Structural Similarity: Fill & Download for Free

An image search engine works very much the same like a normal text search engine (see below for basic building blocks).You are indexing the text on the web pages, and return the images contained on those pages where the index text matches with the query.In addition to the document text also images file names and image alt, title and longdesc attributes can be indexed.In a conventional text search you are displaying a keyword-in-context (KWIC) text summary for each result ( a small text snippet/sentence surrounding the keyword matches on that page), while in image search you are displaying the images which are in a close proximity to the matching keywords.Alternatively to keyword based image retrieval you could implement a content based image retrieval (visual image similarity). See List of CBIR engines .Image search specific building blocksimage extraction: identify all image links and filter out those images likely to belong to menu or layout design (small size, gif format, repetitive on the same site or multiple sites)image description extraction: images file names and image alt, title and longdesc attributes ( Objects, Images, and Applets in HTML documents ) provide additional image description text to be indexedmeta data extraction (optional): image size, number of colors, image formats (jpg/png/eps... ; bitmap/vector ), Exif data (GPS coordinates, orientation ...) this can be used for additional filters to narrow the result setsearch result representation: usually a grid if image thumbnails (vs. a list of text summaries in normal text search)General search engine building blockscrawlerselect documents to indexselect parts of the document you want to indexregularly update the index and rankings if documents have changed, are added or deletedfollow references to other documentsdeal with duplicates and canonizationparserremove HTML markup and extract textbreak text into wordsnormalize capitalization, hyphens and umlautsrankingrank the documents by relevance, time etc.query processingparse query into termsparse query for phrase and Boolean search operatorsdeal with typoscreate query suggestionsimplement substring search / instant searchsearchfind documents matching the query and additional filters, sorted relevancelayout the search result listsindexstore the documents in a data structure which allows scalable, fast and Boolean searchingInverted index Inverted index data structure: Basically for each word or term you are creating a list with URLs of those documents containing the word. The lists can be stored either as files in the file system or in a NoSQL database for persistence. The core of most NoSQL databases is a key value store based on a Hash table . During indexing and searching you transform the search term to a hash. The hash serves as key, while the inverted lists are the value. This allows a near O(1) lookup performance. The inverted index allows Boolean searches by intersecting the lists of multiple keywords.An alternative approach is the Vector space model . Each dimension corresponds to a separate term. If a term occurs in the document, its value in the vector is non-zero. Vector operations can be used to compare documents with queries.cachingload balancingredundancyanalytics

What Is A Browser Engine?A browser engine can be thought of as the heart of a browser, it helps to present the content of a website after you hit the URL of the web address you wish to visit. It does so by understanding the HTML, CSS, and JavaScript written on your web page. Sounds pretty simple, isn’t it? Well, not really, because browser engines are uniquely designed for every browser. Which is why each browser engine has its own way of interpreting the web, leading to cross browser compatibility issues (https://www.lambdatest.com/blog/fixing-javascript-cross-browser-compatibility-issues/?utm_source=Quora&utm_medium=Ans&utm_campaign=RJ-05092019-5&utm_term=Rahul).What comprises a browser engine?Now, a browser engine should not be confused by a rendering engine. A browser engine is responsible for everything from the text you see in the HTML code to the graphical presentation of that code on the browser. With the help of Javascript engine and rendering engine, it is able to do its job. Meaning, a browser engine comprises of 2 more engines:Rendering EngineJavaScript EngineHow JavaScript & Rendering Engine Came Into The Picture?The first time the internet came into the world, very few people had access to it. The user and the developer both were very few in number and the websites that were developed were static and simple. It was not like what it is today. Nobody knew about the dynamic functionality of the website. Actually, how would have they? Javascript was not born and was not required as such at that time. The invention of the browser engines started when Netscape and Microsoft started competing with each other for the popularity of their browsers.Initially, to compete with Microsoft, Netscape developers decided to implement few functionalities keeping in mind the user experience and finalized Scheme language as their language category to move ahead. The goal was to modify the coding experience and introduce flexibility into the website world. Remember, that this was a time when the internet had just gotten started and as Jack Ma once said that when he introduced the internet to his friends, it took 20 minutes to load a page. Just as Netscape was to start the project, Netscape collaborated with Sun Microsystem to use their more static language, Java, along with their idea of scheme language. This gave birth to Javascript.Javascript opened endless opportunities for web developers to use on their website since it was more than just styling or putting tags on the web. This put down huge responsibility on the shoulders of the browser engine because it was not converting just tags to visual elements. It has to work in the backend too. The work that browser engine was doing previously was divided into new engines called Rendering engine and JavaScript engine.Since that time, Javascript, websites and browser engines all have been evolving at an enormous rate. These two components are dependent on each other and need each other to work. The browser will collapse to render a website if even one of them falls.How Do They Differ? Rendering Engine And JavaScript EngineEarlier everything was done by browser engines only but the modern web continues to develop at a pace where it became troublesome for the browser engine to handle it alone. As a result, it introduced 2 types of engine JavaScript Engine and Rendering Engine. Let us understand how these Engines contributes to the overall rendering experience of a browser.1. Rendering EngineA rendering engine is often used interchangeably with browser engines. It is responsible for the layout of your website on your audience’s screen. You are able to read this font in grey color because of the rendering engine. A rendering engine is responsible for the paint, and animations used on your website. It creates the visuals on the screen or brightens the pixels exactly how they are meant to be to give the feel of the website like how it was made to be. So when we say the page is rendered correctly on the screen, we are actually appreciating the rendering engine capabilities. Here is a list of rendering engines produced by major web browser vendors.Blink – Used in Google Chrome, and Opera browsers.WebKit – Used in Safari browsers.Gecko – Used in Mozilla Firefox browsers.Trident – Used in Internet Explorer browsers.EdgeHTML – Used in Edge browsers.Presto – Legacy rendering engine for Opera.2. JavaScript EngineJavaScript engine as the name suggests helps to interpret JavaScript code of your website before rendering it in front of your audience. JavaScript Engines were introduced with the purpose of serving themselves as an interpreter.However, every modern browser engine uses them as a compiler to drive faster results with improved performance. Here is a list of JavaScript engines produced by major web browser vendors.V8 – Used with BlinkNitro – Used with WebkitSpiderMonkey – Used with GeckoChakra – Used with Trident & EdgeHTMLNote: The primary difference between a Rendering engine and a JavaScript engine lies around the dependency with browser. The rendering engine is tightly coupled with browser engine, on the other hand, a JavaScript engine can be worked upon even without a browser.The major browser engines comprises WebKit used in Apple’s Safari, Gecko used in Mozilla Firefox, and Blink used in Chrome, Opera. EdgeHTML for Microsoft Edge, Trident for Internet Explorer. However, Microsoft Edge is coming up with a Chromium-based version.Here is an image to help you understand different pairs of Rendering engines & JavaScript engines for major modern web browsers. You will find the Rendering engines on the left & JavaScript engines on the right.Why Should You Care About Browser Engines?A browser engine is much more than just translating the text and running it on the display with the help of rendering section. Let’s see the features of browser engine:Handles Browser Features: Different browsers contain different features. That is how they make space in a user’s heart. For someone who is non-technical, these features attract him into installation and become a loyal user to the browser. Some browsers show the popup and the perform tag management differently and some contains a few features to attract the audience. The feature that the user sees in the browser works because of the browser engine. No matter how small or how big that feature is, if it is in your browser, it is working by browser engine only. Browser engines have codes that enables these features that makes the user like the browser.The Rendering Problem: If you have set up a cross browser testing environment, then you would understand the complexity, a different browsers brings due to incompatibility with your website’s source code. As I stated earlier, a browser engine will render your website in a unique manner than any other browser engine. You could see different rendering issues if your code is incompatible to any browser rendering engine. You could see discrepancies in your website’s CTAs, Sign Up forms, images, typography, etc.Your audience would be using different browsers, because we are not living in an ideal world where all the users are using a single browser for accessing the internet. Which is why, It is now essential to perform cross browser testing on your website as some browser’s functionality might not work on another. We do realize that Chrome is the most popular web browser but it is not the only one. Curious to know about the second most preferred browser based on different geographies?Read our blog on: Which Browsers Are Important For Your Cross Browser Testing?Security of the browser: Browsers are something that are used to access the internet on your machine. Browsers are the most common software that expose someone to the complete world. Since this communication contains your personal information (like what websites are you accessing), these software needs to be secured. The more secure the browser, the better it is for the user. This responsibility is on the shoulders of browser engines. Browser engines protects and perform actions through which the communication between the user and the server remains secured. Browser engines make sure that the browser is safe to surf because ultimately the reputation of the browser depends on the security. Who will use if this browser can leak the information. Along with the communication part, other features of the security are also handled by browser engines.Speed : Speed is what most of us are looking forward to while choosing a browser. If I ask a person about the top features he likes in the browser, one of them will be speed. Even though almost all the major browsers today presents similar speed, still the user includes it in his list of favourites. Speed in technical terms would mean how fast you see a website on your browser after pressing enter. This would mean how fast the instruction execution takes place inside a browser and this part is taken care of by the browser engine. The better the browser engine is, the faster the speed of the browser is. Speed is also one of the factors responsible for the death of IE.Read More: Death Of IE; Its Aftermath On Cross Browser CompatibilityHyperlinks and Web Forms: Hyperlinks are the links that are embedded onto a word, pressing on which, redirects you to another website. A web form is the form that you fill on a website over the internet. The form and the hyperlink contains sensitive information and should be secure to prevent any breach of data about anyone. Hyperlinks and web forms are handled completely by the browser engines.Conversion to DOM for JS Engine: Javascript engine executes and displays all the javascript code. If you have coded a script in JavaScript that will change the text on which you click, this functionality will be made possible by the JavaScript engine. But, JavaScript can work only when the HTML page and its elements on the page have been converted to DOM. JavaScript can do wonders only if the structure it receives is in DOM. DOM or Document Object Model will be designed by browser engines after receiving the text of the page. It is one of the many things browser engine is responsible for.So, you must have guessed how important a browser engine is. It is the heart of any browser. Since we have now understood what is browser engine and how important it is for a browser, it is worth knowing how it started in the first place. Through the next section, we will see the history of the browser engines.How Do Browser Rendering Engines Work?The primary function of a browser rendering engine is to visualize the content requested by users in an interactive view. For instance, if a user requests an HTML script content, the rendering engine’s job is to parse the CSS and HTML. Henceforth, the content is displayed after being parsed through a rendering engine. The scalable dimension-based format ensures a rendered display significantly restoring an original page layout interpreted from its original form, while indulging scaling and panning features of the web content in real-time environment. The interaction between the end-user through an interface & the rendering engine is facilitated by the browser engines. It facilitates with a high-level interface between the User Interface and Rendering engine.A network layer tenders the browser rendering engine with the requested document by the user. The contents available in such document is then transferred in parts of sizes of 8 kilobyte each. In this order, the below points are furthered to accomplish this process as mentioned below :The HTML elements are parsed and then converted into DOM nodes once after the formation of a content tree is ensued. Data styled in both internal and external CSS is also parsed and utilization of visual information along with styling indulges the formation of render tree.Rectangles arranged with specific colours are manageably sorted inside the rendered tree.After the creation of a rendered tree, a layout process is followed where nodes are defined by a precise set of coordinates, which leads them to be visualized on the user-screen.Considering ‘painting’ the final stage in the process, each node of the render tree is defined as per the code written in the backend layer of the user interface.Browser engine is responsible to start loading of a URL and considering care of processes of reloading, backing and forward browsing actions.When a user is supposed to insert a URL in the address space, UI takes the address to the browser engine where it search the domain name out of the URL and confirms its existence in browser and OS caches. If the domain name is not found in both browser and OS caches, then it requests to the Internet Service Provider (ISP) to extract the IP address from Domain Name System (DNS). Hereby, the website receives a request from the browser to retrieve its content.Click Browser Engines for more information

JavaScript-JavaScript is a scripting language that enables you to create dynamically updating content, control multimedia, animate images, and pretty much everything else. (Okay, not everything, but it is amazing what you can achieve with a few lines of JavaScript code.)Uses of Javascript-JavaScript is very easy to implement. All you need to do is put your code in the HTML document and tell the browser that it is JavaScript.JavaScript works on web users’ computers — even when they are offline!JavaScript allows you to create highly responsive interfaces that improve the user experience and provide dynamic functionality, without having to wait for the server to react and show another page.JavaScript can load content into the document if and when the user needs it, without reloading the entire page — this is commonly referred to as Ajax.JavaScript can test for what is possible in your browser and react accordingly — this is called Principles of unobtrusive JavaScript (http://dev.opera.com/articles/view/41-unobtrusive-javascript/) or sometimes defensive scripting.JavaScript can help fix browser problems or patch holes in browser support — for example fixing CSS layout issues in certain browsers.HTML-HTML is the markup language that we use to structure and give meaning to our web content, for example defining paragraphs, headings, and data tables, or embedding images and videos in the page.Uses of HTML-Publish online documents with headings, text, tables, lists, photos, etc.Retrieve online information via hypertext links, at the click of a button.Design forms for conducting transactions with remote services, for use in searching for information, making reservations, ordering products, etc.Include spread-sheets, video clips, sound clips, and other applications directly in their documents.With HTML, authors describe the structure of pages using markup. The elements of the language label pieces of content such as “paragraph,” “list,” “table,” and so on.CSS-CSS is the language for describing the presentation of Web pages, including colors, layout, and fonts. It allows one to adapt the presentation to different types of devices, such as large screens, small screens, or printers. CSS is independent of HTML and can be used with any XML-based markup language. The separation of HTML from CSS makes it easier to maintain sites, share style sheets across pages, and tailor pages to different environments. This is referred to as the separation of structure (or: content) from presentation.Python-Python is an interpreted, object-oriented programming language similar to PERL, that has gained popularity because of its clear syntax and readability. Python is said to be relatively easy to learn and portable, meaning its statements can be interpreted in a number of operating systems, including UNIX-based systems, Mac OS, MS-DOS, OS/2, and various versions of Microsoft Windows 98. Python was created by Guido van Rossum, a former resident of the Netherlands, whose favorite comedy group at the time was Monty Python's Flying Circus. The source code is freely available and open for modification and reuse. Python has a significant number of users.Thanks…Hope this will help you..:)