I am writing an iOS app which is about live object detection. And I need to resize (scale)the video input and use the Metal framework afterwards. But I didn't find any Api provided by apple to do such thing.
I can crop it but scaling it seems harder.
Does anyone know how to do it?
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I am creating simple camera app and I want to add 'image stability' so when hands are shaking the camera does not twitch. Is it possible to do in iOS?
You can do this by getting the raw image from the camera, and only using a subset of the raw image frame, then programmatically picking a new subset for each raw image to use for the next frame. Needless to say, this is a large amount of work and should only be undertaken if you know what you are doing or want to have the most impressive video/picture taking app.
The iPhone 6+ has this built into the hardware and is, I believe, what the previous comment link to avfoundation is talking about.
I am working on an Android application that will use the KLT tracking algorithm. I have downloaded the Android sample provided by BoofCV's website and I have seen the code. However, I need it to work in the background on a different thread without the camera preview while in the front it will be a user interface of some sorts.
Your help is highly appreciated.
You can make camera preview as small as 2x2 pixels effectively making it invisible while still receiving image frames in onPreviewFrame() - that's the way it's done in a BoofCV example application I've found
I'm working on a project and one of the features is to play a video from a rtmp path. I'm trying to find the best way to draw the frames. Right now I'm using a UIImageView and works, but It's not very elegant nor efficient. OpenGL might do the trick but I've never used it before. Do you have some ideas what should I use? If you agree with OpenGL can you give me a code snippet that I could use for drawing the frames?
Thank you.
Is it possible to use Vuforia without a camera for image tracking?
Basically I would like a function I could call with an image as a indata parameter and coordinates of a image target as a result. Does that exist?
It is unfortunately not possible. I've been looking for such an option myself several times while working on a Moodstocks (image recognition SDK) / Vuforia mashup (see these 2 blog posts if you are interested in it), but the Vuforia SDK prevents the use of any other source than the camera.
I guess the main reason for this is that the camera management is fully handled internally by the Vuforia SDK, probably in order to make it easier to use as managing the camera by ourselves is at best a boring task (lines and lines of code to repeat in each project...), at worst a huge pain in the ass (especially on Android where there are sometimes devices than don't behave as expected).
By the way, it looks to me like the Vuforia SDK is not the best solution you can find for your use case: it is mainly an augmented-reality SDK, focussed on real-time tracking, which imply working with a camera stream... so using it to do "simple" image recognition looks really overkill!
I have a Unity/iOS app that captures the user's photo and displays it in the 3D environment. Now I'd like to leverage CIFaceFeature to find eye positions, which requires accessing the native (Objective-C) layer. My flow looks like:
Unity -> WebCamTexture (encode and send image to native -- this is SLOW)
Obj-C -> CIFaceFeature (find eye coords)
Unity -> Display eye positions
I've got a working prototype, but it's slow because I'm capturing the image in Unity (WebCamTexture) and then sending it to Obj-C to do the FaceFeature detection. It seems like there should be a way to simply ask my Obj-C class to "inspect the active camera". This would have to be much, much faster than encoding and passing an image.
So my question, in a nutshell:
Can I query in Obj-C 'is there a camera currently capturing?'
If so, how do I 'snapshot' the image from that currently running session?
Thanks!
You can access the Camera's preview capture stream by changing CameraCapture.mm in unity.
I suggest that you have a look at some existing plugin called Camera Capture for an example of how additional camera I/O functionality can be added to the capture session / "capture pipeline".
To set you off in the right direction. have a look at the function initCapture in CameraCapture.mm :
- (bool)initCapture:(AVCaptureDevice*)device width:(int)w height:(int)h fps:(float)fps
Here you will be able to add to the capture session.
And then you should have a look at the code sample provided by Apple on Facial Recognition :
https://developer.apple.com/library/ios/samplecode/SquareCam/Introduction/Intro.html
Cheers
Unity 3D allows execution of native code. In the scripting reference, look for native plugins. In this way you can display a native iOS view (with the camera view, possibly hidden depending on your requirements) and run Objective C code. Then return the results of eye detection to Unity if you need it in a 3D view.