can a video projector take input? - image-processing

Can a Video projector take input?.. I want to create an augmented reality application where the user will click on the buttons projected in the screen.
Is this possible only with the projector ? or a camera is also needed?
I know that without camera it's not possible. But i don't know much abt the projectors that's why i am asking this question

Projectors can only project... they work with a strong light-bulb that projects the image onto the screen/wall...
If you want some sort of input, you need a camera or another sensor. This could even be a Nintendo Wii Remote:
http://johnnylee.net/projects/wii/
(Have a look at the second project there)
But your projector itself is not capable of getting input... maximum would be infrared from remote controls, but that depends on the projector

You need something like a camera (can also be kinect or something like that) or something like a "touchable wallpaper" (don't know if there is something on the market).
Ciao!
Stefan

http://smarttech.com/us/Solutions/Education+Solutions/Products+for+education/Interactive+whiteboards+and+displays/SMART+Board+interactive+whiteboards
This is pretty well solved.

Related

How to find how much the mobile screen went from the eye's straight line

I have this requirement how to find whether the user is looking down or up the iPhone screen. like if the user have his iPhone in desk and he need to look down to the screen. if the same user taking a photo over his head means how to find it.
Is there is any sensors we need to use?
There is no direct sensor in iPhone that can recognise where your eyes looking but you can use front camera & machine learning to achieve your functionality. For more refer recognize gaze direction

iOS Programmatically take a picture with camera based on what camera sees

I am currently working on an iOS app that can take a picture programmatically using AVFoundation libraries like AVCaptureDevice through a custom button.
The new requirement is that the camera should automatically take a picture when the camera session detects something specific. For example, if the camera is open, and I line up an apple to fill a certain circle part of the capture screen, it should take the picture automatically. We can see this auto capture feature in some banking apps when you submit a mobile check deposit.
Does anyone know of existing libraries(open-source or proprietary) that can analyze images in real time while a user is taking a picture?
The first thing you are going to need to do is decide how you want to detect the apple. You can do this using shape detection, image recognition, or various other methods. This is important because you need to know the approach you want to take before you can identify the best way to implement it.
Once you know how you are going to identify the apple, the easiest way to do real-time image processing like this would be to use an existing augmented reality SDK. For example:
http://www.wikitude.com/products/wikitude-sdk/
http://artoolkit.org/
https://developer.vuforia.com/
If you are feeling really adventurous you could roll your own using AForge or a similar library. I have taken this approach in the past for basic shape detection projects.
Edit
The reason I suggest using an existing AR SDK is because generally they provide a lot of the glue between the camera feed and their API for you and it takes a lot of leg work out of the equation. Even though you won't be using any of the actual "augmentation" part of their SDKs, you can still take advantage of the detection part.
No matter what approach you take, you can think about it in the simplest terms of looking a picture, and figuring out if the item you want is in that picture. How do you decide? In most cases you look for a specific shape or pattern.

How to detect distance using an image (similar to EasyMeasure app)

I am developing an autonomous robot using an iPhone. I want it to analyze images from its camera to determine its distance to objects.
I know it is possible to detect distance using a single, regular camera because there is an app in the app store called EasyMeasure that detects the distance from the phone to the object using only the rear camera.
So my question is: a) what algorithm can achieve this? b) are there any open source libraries out there that do this?
Thank you.
It is not possible without additional scale information about the scene. The app you mention is rubbish. Sorry.

Image tracking - tracking a screen with a camera

I want to track the relative position of a camera aimed at a computer screen.
I can’t control what is displayed on the computer screen but I can receive screen dumps whenever something changes on the screen. Those screen dumps can hopefully be used to find the screen when analyzing the video from the camera.
I see many videos on youtube for face, logo or single colored objects tracking using OpenCV but I’m unsure those methods would work finding and tracking a more detailed image like a screen dump.
Maybe Template Matching is the way to go? But I need to find the screen even at an angle.
Basically I don’t know where to begin and need help from people with experience in this field to find the best way for achieving what I want.
Thanks
Using feature matching should do the trick (Sift/SURF/ORB/...)

How do I fire a camera connected on USB programatically?

I want to make something like they have at US dmv's where you sit down and it takes your picture, maybe like photobooth.
I want to connect a high end camera via usb, fire the camera and get the picture.
There's the Picture Transfer Protocol http://en.wikipedia.org/wiki/Picture_Transfer_Protocol a nastly little thing. All the cameras I held in my hands so far, claiming they had proper PTP support failed it somewhere. But in theory one can use PTP to remote control a camera, i.e. trigger the shutter, retrieve the picture and so on.
Rater than reimplementing the whole thing I recommend you get some readily usable PTP library. There are some open source ones listed on http://ptp.sourceforge.net
The easiest method is probably to use OpenCV: http://opencv.willowgarage.com/wiki/
If you need a high end camera - most digital SLRs have a tethered mode where you can control the camera, fire the shutter and retrieve the image data. Each camera maker has a proprietary (but normally free) sdk.
For a webcam type camera - these normally run in video mode, you simply grab an image out f the video stream - as PaulR says - use openCV

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