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Archive of posts filed under the Windows Phone Development category.

Green Screen Magic for Windows Phone organized another Imaging challenge for developers. This time I decided to play with the chroma key and I created two Green Screen applicatons.   You can find my article from Nokia wiki: Green_Screen_Magic(Chroma_Key)_with_Nokia_Imaging_SDK

Green Screen Helper, an app to help users set up a high quality green screen in preparation for Chroma Key photography. The application uses the chroma key filter in real time to make a selected colour black – enabling the user to see which parts of the screen will not be properly filtered when applying the chroma key filter. This is helpful, since it then becomes easy to see where the editing scene needs to be fixed – by adjusting the lights, or fixing wrinkles. In addition, the hue range sensitivity accepted by the filter can be adjusted: a broader hue range will be more tolerant of poor lighting and wrinkles in the background, but may result in some of the subject also being selected.

The other application is called Green Screen Magic, it’s a simple photo editing app which will replace the green screen area with a background. This app uses the same approach as the previous app to help the user to select the chroma key, and adjust sensitivity. After that it uses the blend functionality to combine two images.

Face Detection on Windows Phone organized an Imaging challenge for developers. I haven’t done much with wp8 lately, so I decided to take part to the competition.  The winning articles were really good, and this time I wasn’t one of them. But it doesn’t matter I had a lot of  fun with facial recognition on Windows Phone.  You can find my article from Nokia wiki:

I ported the facedetectwp7  library to the Windows Phone 8, and I added a new simple example app showing how to use the library. You can get my wp8 port from my github-repo:

Here’s the example application from facedetect library in action:

Windows Store

You can also play with this example just by downloading the app from Windows Store:

My Windows 8 / Hyper-V Rant

The new lumia phones are looking really good, and I wanted to develop something for it. I started by porting a cocos2d-x game, and I also won a Lumia 820 with my cocos2d-x porting entry.

To develop  for wp8 you’ll need the Windows 8 Pro edition. It costs only about 30 EURs, so it’s kind of no brainer to buy it. The biggest issue for me with wp8 is that the emulator is build on top of Microsoft’s own virtualization platform called Hyper-V.


The Hyper-V is a windows virtualization service that give you an opportunity to run different operating system under the virtualization service. It gives you pretty much the same features as VM-Ware, or Virtual Box, but it’s built as windows service, so you could run multiple operating systems inside that one service.

The Hyper-V steals the virtualization extensions from your processor

This is pretty irritating. The Hyper-V is a service (starts on windows startup) that takes my processors virtualization extensions into use so I can not run any other virtualization software when I have this crap enabled. For example BlackBerry emulator is running on top of VM-Ware, and it can not be used while the Hyper-V is enabled. I also like to develop for Linux with Ubuntu running on Virtual-Box, but that’s also not going to happen with Hyper-V enabled :(

You need to boot twice after enabling/disabling Hyper-V

This is also very annoying, since I have to constantly disable / enable the Hyper-V when developing for other platforms than wp8. After disabling the Hyper-V your pc will boot, and on that boot you’ll get “configuring windows features” dialog, and after that the PC will boot once more with the new config that has Hyper-V enabled/disabled.

Microphone input does not work

This is true WTF material. The microphone input on my motherboard doesn’t work after enabling hyper-v. It has a lot of staic noise, and it’s normal again when I’m disabling Hyper-V. I bough a USB-microphone to solve this issue. However running any other virtual machines like VM-ware does nothing to the mic input. I have no idea what the Hyper-V is doing…

Enabling the Network connection on the emulator disconnects the desktop

Another WTF. If I enable the network connection on the windows phone emulator, then the network connection drops from my desktop PC. Developing app that requires a network connection is not feasible with the current emulator.

Continue reading ‘My Windows 8 / Hyper-V Rant’ »

The Myth of GPL Being Banned in Microsoft Marketplace

There has been a lot of talk about GPL being incompatible with Microsoft market place (as with Apple’s appstore). For example this Arstechnica post from 2011.

I think that this is pretty important topic now with WP8, since we could use so much GPLv2 licensed C++ libraries with our app, that it really hurts to think that the GPL is not allowed in the marketplace. However that is not true anymore! I just downloaded WordPress client from the marketplace, and you had to accept GPLv2 license before using the software. It seems that GPLv2 is acceptable now! However, I’m still pretty sure that GPLv3 is not compatible with appstore, since it has some DRM system on it.


GPLv2 license with WordPress client

Myth Busted!

Tweejump for Windows Phone 8

I started my wp8 development by playing around with Cocos2d-x port for wp8. I also used this start by participating to the wiki-competition with my article about Porting Cocos2d-x Games for Windows Phone 8. You can see the port running on the video below. I had really good time with cocos2-x, and I think that I might even make my own game based on this framework. It’s really easy to use, and you can port the games created with it so easily to iOS, and for Android as well.

The source code

The source code for tweejump can be found from: