Customised focus on IOS camera - ios

Is it possible to create our own focus on IOS camera for our application, so that it may recognise the object when the iOS camera is over it.
For example I have an rectangular area on a sheet of paper and when I put the camera in front of the paper it highlights the focus on the rectangular region, like the Face Identifier.
So, is this possible. If yes then how?

This isn't focus, it's shape recognition. IIRC only face recognition is built in so you need to do this yourself or use a 3rd party solution. Doing it yourself you probably want to use open-cv, 3rd party would be something like metaio.

Related

Detecting a real world object using ARKit with iOS

I am currently playing a bit with ARKit. My goal is to detect a shelf and draw stuff onto it.
I did already find the ARReferenceImage and that basically works for a very, very simple prototype, but the image needs to be quite complex it seems? Xcode always complains if I try to use something a lot simpler (like a QR-Code like image). With that marker I would know the position of an edge and then I'd know the physical size of my shelf and know how to place stuff into it. So that would be ok, but I think small and simple markers will not work, right?
But ideally I would not need a marker at all.
I know that I can detect e.g. planes, but I want to detect the shelf itself. But as my shelf is open, it's not really a plane. Are there other possibilities to find an object using ARKit?
I know that my question is very vague, but maybe somebody could point me in the right direction. Or tell me if that's even possible with ARKit or if I need other tools? Like Unity?
There are several different possibilities for positioning content in augmented reality. They are called content anchors, and they are all subclasses of the ARAnchor class.
Image anchor
Using an image anchor, you would stick your reference image on a pre-determined spot on the shelf and position your 3D content relative to it.
the image needs to be quite complex it seems? Xcode always complains if I try to use something a lot simpler (like a QR-Code like image)
That's correct. The image needs to have enough visual detail for ARKit to track it. Something like a simple black and white checkerboard pattern doesn't work very well. A complex image does.
Object anchor
Using object anchors, you scan the shape of a 3D object ahead of time and bundle this data file with your app. When a user uses the app, ARKit will try to recognise this object and if it does, you can position your 3D content relative to it. Apple has some sample code for this if you want to try it out quickly.
Manually creating an anchor
Another option would be to enable ARKit plane detection, and have the user tap a point on the horizontal shelf. Then you perform a raycast to get the 3D coordinate of this point.
You can create an ARAnchor object using this coordinate, and add it to the ARSession.
Then you can again position your content relative to the anchor.
You could also implement a drag gesture to let the user fine-tune the position along the shelf's plane.
Conclusion
Which one of these placement options is best for you depends on the use case of your app. I hope this answer was useful :)
References
There are a lot of informative WWDC videos about ARKit. You could start off by watching this one: https://developer.apple.com/videos/play/wwdc2018/610
It is absolutely possible. If you do this in swift or Unity depends entirely on what you are comfortable working in.
Arkit calls them https://developer.apple.com/documentation/arkit/arobjectanchor. In other implementations they are often called mesh or model targets.
This Youtube video shows what you want to do in swift.
But objects like a shelf might be hard to recognize since their content often changes.

Automatically take a picture to proceed on back thread when rectangle detected? iOS, Swift

I am working on a project at the moment and wanted to find out what I need to be looking at to automatically take a picture when a rectangle is detected. I have seen this in action on an app called car spotter but wanted to know how it could be done. On car spotter it detects the rectangle and blurs the number plate automatically.
You can use AVCaptureSession to capture pictures from camera, and use CIDetector to detect rectangle. They are all system APIs, doesn't need OpenCV which costs extra storage space.
And there is an implementation example on Github:
https://github.com/charlymr/IRLDocumentScanner
And the key procedures are in this class:
https://github.com/charlymr/IRLDocumentScanner/blob/master/Source/Private/IRLCameraView.m

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.

Reproduce Google Heart with iOS7 MapKit's custom tiles

I would love to reproduce GoogleHeart-like 3D map flyover even when offline.
As of iOS 7 MapKit allows us to draw custom offline tiles. It also allows us to set a Camera in order to see the map in 3D or 2.5D as you may wish to call it.
I was wondering: can I draw a 3D shape like Apple does for its flyover feature, on my custom tiles?
I need to apply a "bump-map" to the map in order to get a GoogleHeart-like 3D view and I was wondering if Apple would allow me to do just that with iOS 7 and custom tiles rendering + camera settings.
Thanks
I have experimented pretty extensively with this, but there is no supported way to do this. Right now, Apple only offers raster tile-based overlay, albeit with automatic 2.5/3D transformation when overlaid on a map. Hopefully in the future they will support 3D API and/or custom, say, OpenGL-based augmentation to the map.

Blur effect in a view of iOS

I want to use an UIImagePicker to have a camera preview being displayed. Over this preview I want to place an overlay view with controls.
Is it possible to apply any effects to the preview which will be displayed from camera? I particularly need to apply a blur effect to the camera preview.
So I want to have a blurred preview from camera and overlay view with controls. If I decide to capture the still image from the camera, I need to have it original without blur effect. So blur effect must applied only to the preview.
Is this possible using such configuration or maybe with AVFoundation being used for accessing the camera preview or maybe somehow else, or that's impossible at all?
With AV foundation you could do almost everything you want since you can obtain single frame from the camera and elaborate them, but it could lead you at a dead-end applying a blur on an image in realtime is a pretty intensive task with laggy video results, that could lead you to waste hours of coding. I would suggest you to use the solution of James WebSster or OpenGL shaders. Take a look at this awesome free library written by one of my favorite guru Brad http://www.sunsetlakesoftware.com/2012/02/12/introducing-gpuimage-framework even if you do not find the right filter, probably it will lead you to a correct implementation of what you want to do.
The right filter is Gaussian blur of course, but I don't know if it is supported, but you could do by yourself.
Almost forgot to say than in iOS 5 you have full access to the Accelerate Framework, made by Apple, you should look also into that.
From the reasonably limited amount of work I've done with UIImagePicker I don't think it is possible to apply the blur to the image you see using programatic filters.
What you might be able to do is to use the overlay to estimate blur. You could do this, for example, by adding an overlay which contains an image of semi-transparent frosted glass.

Resources