Categories
graphics Mobile phones programming video vision Website

iPhone OS 3.x Raw data of camera frames

Hi All
It looks like it’s finally here – a way to grab the raw data of the camera frames on the iPhone OS 3.x.
Update: Apple officially supports this in iOS 4.x using AVFoundation, here’s sample code from Apple developer.
A gifted hacker named John DeWeese was nice enough to comment on a post from May 09′ with his method of hacking the APIs to get the frames. Though cumbersome, it looks like it should work, but I haven’t tried it yet. I promise to try it soon and share my results.
Way to go John!
Some code would be awesome…
Roy.

Categories
graphics Mobile phones video

iPhoneOS 3.1 will not allow marker-based AR

no-arHi
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.

Categories
graphics Mobile phones programming video vision

Near realtime face detection on the iPhone w/ OpenCV port [w/code,video]

iphone + opencv = winHi
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

Categories
3d graphics Mobile phones opengl programming video

Augmented reality on the iPhone using NyARToolkit [w/ code]

nyarrrHi
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…

Categories
graphics programming video work

iPhone camera frame grabbing and a real-time MeanShift tracker

i_can_has_meanshiftHi
Just wanted to report on a breakthrough in my iPhone-CV digging. I found a true realtime frame grabber for the iPhone preview frame (15fps of ~400×300 video), and successfully integrated this video feed with a pure C++ implementation of the MeanShift tracking algorithm. The whole setup runs at realtime, under a few constraints of course, and gives nice results.
Update: Apple officially supports camera video pixel buffers in iOS 4.x using AVFoundation, here’s sample code from Apple developer.
So lets dig in…

Categories
programming

So you're trying to get your homemade app on your pwned iPhone

Recently I was working on an iPhone app for work, for demo purposes, but my company cheaped out on the Apple iPhone Developers registration. 

More accurately, the process of binding a multi-million-$-a-year company with Apple Inc. takes a very long time, so we took the back-door and just pwned our test iPhone devices (firmware 2.1).
iphone
“How hard can it possibly be to install apps on a jail-broken iPhone?” we thought, Well as it turns out, it’s pretty difficult, especially for Mac-first-timers like myself. 
In the end, I overcame this obstacle – but not before compiling a compiler, installing a gazillion support apps, compiling my app with at least 6 different compilers, doing it on WinXP, Ubuntu, on the iPhone itself, and on the Mac.
So I thought why not share with you the way that actually produced the working result.