How do I use my smart phone camera as a webcam in MATLAB?

I have an smartphone device with a camera. I would like to obtain and process this image data in MATLAB.

(Specifically, I have an Android device).

Answer 1

The general solution would need two parts, one to broadcast the data from the device and another part to read this data into MATLAB.

A specific solution for Android:

• Install the free IP Webcam app. (Make sure you read the corresponding permissions and understand any security issues therein)
• Open the app, set the desired resolution (will impact the speed!)
• Scroll to the bottom and tap on 'Start Server'
• In the camera preview window, note the url at the bottom of the screen.
• Open MATLAB and use this code snippet to obtain a live preview window. Note that this uses JPG files for discrete frames, which is probably not the fastest way. The app can stream the video and/or audio in multiple ways.

url = 'http://<ip address>/shot.jpg';
ss  = imread(url);

fh = image(ss);
while(1)
    ss  = imread(url);
    set(fh,'CData',ss);
    drawnow;
end

Example:

(If you find faster ways/solutions for other devices, post it here!)

Nice recursive ML screen. +1 for that!

I use a 'dumb' phone so can't provide real feedback ;)

Its really fun to see it build it up! (i.e its not super fast :()

Is there a similar app for iOS?

http://itunes.apple.com/us/app/ip-cam/id333208495?mt=8 appears close enough. Care to try and post another answer?

hi, i want to know that can we change this rgb image into grayscale or binary image. i have tried but failed. so any suggestion plz

set(fh, 'CData', rgb2gra(ss));

And be sure that you have done

 colormap(gray(256))

after the original image() call.

Answer 2

With the iPhone, using the App suggested by Ashish above (IP Cam), you can achieve the same pretty easily! The code is exactly the same:

url = 'http://<ipaddress>:8020/image.jpg';
ss  = imread(url);
fh = image(ss);
while(1)
    ss  = imread(url);
    set(fh,'CData',ss);
    drawnow;
end  

Nice Fractal, +1

Hi, Excuse me for my bad English. I'm using IP webcam for Android.I used
url = 'http://158.124.30.101:8080/shot.jpg';
ss = imread(url);
fh = image(ss);
The video is excellent but my problem is that I want to use a bounding box to sellect a red object in the video. I don't know if it's possible. Can anyone help me?thanks

Francisco, you'll get a better answer if you ask this as a new question: http://www.mathworks.com/matlabcentral/answers/questions/new

(also look at http://www.mathworks.com/matlabcentral/fileexchange/28512-simple-color-detection-by-hue for example)