Performance Evaluation of Digital Image Processing on the Web using WebAssembly

Sammanfattning: JavaScript has been the de-facto standard programming language for Web browsers for some time. Although it has enabled the interactive and complex web pages we have today, it has long been characterized by performance issues. A promising new technology, WebAssembly, aims to enable near-native performance on the Web. WebAssembly is a binary instruction format designed as a compilation target for programming languages like C/C++. This allows developers to deploy their applications for execution in a Web browser environment.  Previous benchmarks have examined the performance of WebAssembly and observed a varying performance slowdown of 10% to around 55% slower than native. Recent additions to the WebAssembly standard, such as the support for SIMD instructions and multithreading, enables even greater performance and new benchmarks need to be constructed.  This thesis explores the performance implications of these new features by applying them in the domain of digital image processing, which is particularly suited for such optimizations. The OpenCV library was used to construct two benchmark suites, one running natively and one running in two different Web browsers using WebAssembly. The results of the benchmarks indicate that, although in some cases performance approached native performance, the mean slowdown was approximately double compared to native code.