More Than Technical

Archive for the ‘Mobile phones’ Category

Hi

I had very high hopes for iPhoneOS 3.1 in the AR arena. With all the hype about it, I naturally thought that with 3.1 developers will be able to bring marker-detection AR to the app-store – meaning, using legal and published APIs. A look around 3.1′s APIs I wasn’t able to find anything that will allow this.

Not all AR is banned. In fact AR apps like Layar will be very much possible, as they rely on compass & gyro to create the AR effect. These don’t require processing the live video feed from the camera, only overlaying data over it. This can be done easily with the new cameraOverlayView property of UIImagePickerController. All you need to do is create a transparent view with the required data, and it will be overlaid on the camera preview.

Sadly, to get marker-detection abilities developers must still hack the system (camera callback rerouting), or use very slow methods (UIGetScreenImage). I can only hope apple will see the potential of letting developers manipulate the live video feed.

Roy.

Hi
OpenCV is by far my favorite CV/Image processing library. When I found an OpenCV port to the iPhone, and even someone tried to get it to do face detection, I just had to try it for myself.

In this post I’ll try to run through the steps I took in order to get OpenCV running on the iPhone, and then how to get OpenCV’s face detection play nice with iPhoneOS’s image buffers and video feed (not yet OS 3.0!). Then i’ll talk a little about optimization

Update: Apple officially supports camera video pixel buffers in iOS 4.x using AVFoundation, here’s sample code from Apple developer.
Update: I do not have the xcodeproj file for this project, please don’t ask for it. Please see here for compiling OpenCV for the iPhone SDK 4.3.

Let’s begin
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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
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Well, At least when it comes to SIP communication

Update:
Well, there has been a great leap in Android support with VoIP. Skype has released a decent client for most Android based phones (with the exception of Galaxy S, and USA Based clients cannot use 3G), and I have discovered another excellent VoIP client for Android called cSipSimple (If you liked Sipdroid I advise you to check this one out as well. It’s my current default).
Other than that, the upcoming Android 2.3 is said to have native SIP support which is extremely cool
Having said all that, enjoy my original post

A Smartphone, as its name implies is… eventually… a smart phone! Exactly! That’s what I thought. And as one I should have the ability to run any software that is compatible with its hardware and software.

That turns out to be almost true. VoIP is off the limit.

And it is not because the device cannot handle it, Far from it. It is because mobile companies are afraid for their revenues. When people are using VoIP on their infrastructure, it takes away money from them. Oh you poor phone companies. My heart goes out for you.

And after all the tears run out, I went out to look for some VoIP that DOES work for me. SKYPE of course was off limit. Even though there is “Skype Lite Beta” for Android, it does not support Skype-to-Skype user call. And why should it? Skype is an excellent IM software and VoIP is only secondary (wink).

I then stumbled upon SipDroid. Sip droid is a SIP client for android. This is great if you have a SIP account provider. I for instance, have an account which runs on asterisk server (open source IPBX system).

I got the installation of SipDroid at once! And installed on my phone to try it.

What can I say? It has huge potential. But it is only fully compatible with its mother ship, which is pbxes.com. Luckily (but of course – not a solution) they allow you to enter your own sip account there so you can connect to it through them (like connecting to your neighbor through china… but it works). Although pbxes.com has a strange certification error they claim is negligible.

So, using it directly with asterisk server causes poor outgoing audio which is lame. I’m sure some people might be able to tweak their server to handle it directly and properly but I didn’t manage to do that… nor found proper idea sharing on that subject.

But this client is still in beta stage so I honestly believe it will kick ass when it’s complete.

It’s no Skype, and I hope some Skype-like client like Fring will port soon for Android, but until then, it’s better than nothing.

Two important notes if you want to use it:

1. If you are planning to download it from the Android Market – You will get a limited version which disables usage of VoIP over 3G/EDGE. So if you want the full one then download it directly from the project page.
2. VoIP data, is currently 1.20mb per minute, so watch your data plan

Hi

I saw the stats for the blog a while ago and it seems that the augmented reality topic is hot! 400 clicks/day, that’s awesome!

So I wanted to share with you my latest development in this field – cross compiling the AR app to the iPhone. A job that proved easier than I originally thought, although it took a while to get it working smoothly.

Basically all I did was take NyARToolkit, compile it for armv6 arch, combine it with Norio Namura’s iPhone camera video feed code, slap on some simple OpenGL ES rendering, and bam – Augmented Reality on the iPhone.

Update: Apple officially supports camera video pixel buffers in iOS 4.x using AVFoundation, here’s sample code from Apple developer.

This is how I did it…
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Last week I got a hold of the HTC G1 Android Developer Phone. This (how else) was preceded by a big fight with my cellular operator who insisted that I will take a data plan.

Ok, I said to myself, I bought this phone so that obviously mean I will use cellular internet. “So how much is that data plan?” I asked the representative.

“It’s 1000K” she replied. “1MB?” I asked in wonder. “No, not 1MB – 1000 KB!”

That’s when I understood she has no clue what she’s talking about. Furthermore, this “joke-data plan” was limited to WAP browsing. Oh come on!!!!

And I can’t replace it for a real data plan; I have to add money on top of it!

Well, I do not want to bore you with this specific war, because this is only a prolog for this post, but let’s just say it pays off to be stubborn. I ended up with no obligation to any data plan (which of course I took one, but now I can cancel it any time).

Now that I’ve got THAT over with, I got around to checking out this wonderful phone (and forgive me iPhone fans – I’m not saying this is BETTER than iPhone, only that it’s DIFFERENT).

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