Categories
code ffmpeg graphics opencv video vision

Extending the hand tracker with snakes and optimizations [w/ code, OpenCV]

I wish to report of a number of tweaks and additions to the hand silhouette tracker I posted a while back. First is the ability for it to “snap” to the object using a simple Active Snake method, another is a more advanced resampling technique (the older tracker always resampled after every frame), and of a number of optimizations to increase the speed (tracker now runs at real-time on a single core).

Categories
code opencv vision Website

Simple Kalman filter for tracking using OpenCV 2.2 [w/ code]

Hi,
I wanted to put up a quick note on how to use Kalman Filters in OpenCV 2.2 with the C++ API, because all I could find online was using the old C API. Plus the kalman.cpp example that ships with OpenCV is kind of crappy and really doesn’t explain how to use the Kalman Filter.
I’m no expert on Kalman filters though, this is just a quick hack I got going as a test for a project. It worked, so I’m posting the results.

Categories
Android Java Mobile phones programming Solutions work

First steps in Android programming

Last week I finished my first Android application. All through the development stage I had to Google a lot for examples which some were really hard to find (even though you can find reference for everything in the SDK, for me, it’s easier to understand from a code sample).
My mobile company allows you to send 10 free daily SMS through their website, and after that each text message is still half priced, so I decided to take a challenge and create a UI that allows me to send my messages from the phone through the website automatically.
The core of my software was pure java, so even though it wasn’t straight forward to accomplish, I kinda know the material.
The main issues were after – when I got to the android implementation and UI
Here are the issues I needed, and will supply examples for in this post:
(Of course – for you that are more experienced than me with Android development, please forgive if I’m not doing everything ‘by the book’, it’s simply what I could find. So if you have any suggestions or improvement please send them to me or post a comment J )

  • How to find out if there is an active network on the device
  • How to create options menu
  • How to create and clear notification in the notification area
  • How to declare your program as “SMS Sender” (‘Complete action using…’)
  • Taking care of orientation (Landscape and Portrait mode for UI)

Here is the code I ended up using. Hope you find it helpful