Latest posts

Ramandeep Singh Nanda

Template matching with OpenCV

For structured (bounding box based) text extraction, it becomes imperative that the received image and target image are aligned properly and to scale. OpenCV is a great image processing library that has a ton of features.

To align source and template images, following steps are required.

  • First convert images to …

Ramandeep Singh Nanda

Android Implementing Google Sign In

As you all are aware that Google Plus is shutting down in March 2019 and so are all its services. I have had a legacy android app on play store that was using the GoogleApiClient for authentication with Google Plus services, alas, I had to upgrade the application to use …

Ramandeep Singh Nanda

Java WatchService

In this post, I will cover a tutorial that involves different moving pieces. It covers the following:

  • Java WatchService
  • Spring Boot
  • Initialization-on-demand holder idiom
  • Managing concurrency
  • RXJava
  • Lombok (because why type more?)

The example will expose a Spring Boot REST service that exposes csv file records from a directory. In …

Ramandeep Singh Nanda

Reactively Streaming CSV using RXJava

RXJava is an extremely useful streaming framework (here is an example application using it for parallel processing of restful calls to both uber and lyft (RT_UBER_NYC_TAXI)). However, In this post, I will cover how you can reactively stream and process a CSV file.

Firstly, you can create a Flowable of …

Ramandeep Singh Nanda

Spark Scaling to large datasets

In this post, I will share a few quick tips about scaling your Spark applications to larger datasets without having large executor memory.

  • Increase Shuffle partitions: The default shuffle partitions is 200, for larger datasets, you are better off with larger number of shuffle partitions. This helps in many ways …