LSH – an efficient approach to nearest neighbour search

In Image similarity search with LIRE we explained how to compare and find similar images using the Java library LIRE. The idea was to transform the complicated problem of comparing a large bunch of pixels to the simpler problem of comparing vectors representing histograms and other higher-level properties. In other words, if we can compress the information inherent in a bunch of pixels to a point in n-dimensional space (an array with n entries – the so called feature vector of the image), we can regard the distance between two such points as a similarity measure for the corresponding images. We can then find the images similar to a search image by selecting those images whose feature vectors have a small distance to the feature vector of the search image.

However, a naive approach to the problem – comparing the feature vector of the search image to all feature vectors in the database – is rather slow if our database is large. In this article, we show how to implement a fast similarity search for even very large databases.


Ivory Becomes FOS Now – CKEditor Bundle for Symfony

Maybe you heard about it: The Symfony Bundle „egeloen/ckeditor-bundle“ was looking for a new maintainer. And the Symfony 4 compatibility was missing. Having the downloads in mind I did not expect it to be that difficult to find new maintainers. At the end Marko Kunic and I took that place. But let us take a look back into the history.

Of Love and Hate: TypeScript, Redux and immutable.js

I love Redux. It’s such an elegant and simple concept that solves so many problems. But like every other solution, adding new concepts to your code base can also introduce the occasional headache.

One of these headaches is that Redux does not enforce a lot of it’s conventions, but when you don’t adhere to them, things start breaking further down the road in strange ways.

Today, I’m going refer to one of Redux‘ three principles: State is read-only

Three ways to create Word documents with PHPWord

Creating Microsoft Word documents in PHP can be a challenge. Word offers a multitude of options and settings and while creating a document in PHP you want do take advantage of those options to achieve a satisfying result. Perhaps you need to dynamically create documents for a client and the client will only know the capabilities of Mircosoft Word, but not the limitations of PHP libraries. This can result in an unsatisfied client.

In this article we will take a closer look at PHPWord and three different ways to create Word documents with it: basic easy templating, the creation of Word documents from scratch, and (going a little crazy there) the combination of both by merging existing templates with dynamically created documents. Hopefully, after reading through the text, you will have an idea of how to implement the perfect Word creator for your needs.

DreamFactory Intermediate Service

DreamFactory is a BaaS (Backend as a Service) that connects a multitude of data sources to APIs that apps can connect to. With our Agile Anti-Pattern App (MAPA), we wanted to move the patterns database out of the app, so that we did not have to publish a new version of the app every time we added or changed patterns. The simplest way for this was to put the complete data set (a tiered json file) on a webserver and tell the app to download from there. This would solve the problem, but be a pain to edit or version. The optimal solution would of course be a somewhat normalized database of patterns, their symptoms, their remedies, categories and a pattern-categories relation.

React gets Context & Suspense. Quo vadis, Redux?

Disclaimer: this article targets developers that are using Redux with React. If you are using Redux with another Framework, this article might not be important for you.

Last thursday, Dan Abramov gave a talk on JSConf Iceland called „Beyond React 16“. A few hours later, featured an article titled RIP Redux: Dan Abramov announces future fetcher API. While I agree with almost nothing that article has to say about Redux, the article got one thing right: Somewhere between 6 or 12 months from now, the way we are using Redux (at least when starting a new project) will be drastically different from the way we are using it today.

But before we take a gaze into the crystal ball, let’s take a step back and see what happened.


Of races and mutexes: synchronizing async operations in JavaScript

While JavaScript is a strictly single-threaded language, the asynchronous nature of its execution model can easily lead to situations in which two or more async operations run at the same time and compete with the program flow depending on which operation succeeds first. The result is a specimen of the dreaded species of race conditions.

Issues of this type can be arbitrarily hard to reproduce, debug and fix, and I guess that every seasoned JavaScript developer can relate one or two horror stories where they literally spent days before finally fixing such an issue for good.

Race conditions are a well-known problem from any language that supports for concurrency, and often a mutex is used as a tool to synchronize such operations. This article shows how to apply the concept of mutexes to JavaScript in order to avoid race conditions.


Travel Your Project

As a traveler and project guy, I often noticed that these two important things in my life have a lot in common. Things that happen while I’m on the road are similar to situations I observe in my daily project business. When I struggle in a new or existing project I often think about similar situations I had on journeys with my backpack.

9 Tips How Travel Experience Will Improve Your Project Skills

Traveling people are described to gain skills abroad that help them in their everyday life. Not only in everyday life, but also in projects or working environment. So „traveling your project“ could be a legit approach in dealing with certain situations. Some of the skills I think to be helpful are collected in this article.


From Vagrant to NixOps

I have been following the development of NixOps for some months. NixOps is a cloud deployment tool using nix, the functional package manager for unix systems. Nix makes it very intuitive to define absolute package dependencies. No more thinking and guessing about required runtime dependencies.
NixOps supports deploying to different platforms. Bare-metal, cloud, and even virtual environments like virtualbox work out of the box. I have worked in many projects using vagrant. Out of curiosity I migrated an existing vagrant project using wasted (Web Application STack for Extreme Development) to nix and NixOps.
This post is a walkthrough to configure a symfony2 project with nginx, mysql, and php-fpm from scratch. Weiterlesen

mobile dev hint #2 – Use Browsersync for mobile testing

While testing mobile websites on different devices and browsers, testing time grows exponentially. You need to duplicate click-through movements on all the devices, fill out forms many times and do all the user interaction for too many times. This is where Browsersync starts, it cuts out all the repetitive manual tasks. You can mirror all interactions on your testing devices and you  can integrate Browsersync in your web platform and build tools easily. The CLI usage is simple and developer friendly and the great UI can help the testers to interact with the software live during the testing. Weiterlesen