I'm trying to mod Oculus World Demo to show an video stream from a camera and not a pre-set graphic, however, I'm finding it difficult to find the proper way to render an cv::IplImage or cv::mat image type onto the Oculus screen. If anyone knows how to display an image to the oculus I would be very grateful. This is for the DK 2.
Pure OpenCV isn't really well suited to rendering to the Rift, because you would need to manually implement the distortion mechanisms that are normally provided by the Oculus Rift SDK.
The best way to render an image from OpenCV onto the screen is to load the image into an OpenGL or Direct3D texture and use the 3D rendering API (GL or D3D) to place it into a rendered scene. There is an example of this in Github repository for my book on Rift development.
In summary, it sets up the video capture using the OpenCV API and then launches a thread which is responsible for capturing images from the camera device. In the main thread, the draw call renders a simple 3D scene which includes the captured image. Most of the interesting Rift related code is in the parent class, RiftApp.
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I am currently working on a service to update the content of the video bases on the markers present in the video. I was curious if we can use Vuforia to achieve the same by providing the pre-recorded video as an input to Vuforia instead of the live camera feed from the mobile phone.
TLDR; This is not possible because replacing the camera is not a function that neither Vuforia or ARKit expose.
Aside from not exposing the camera both frameworks use a combination of camera input and sensor data (gyro, accelerometer, compass, altitude, etc) to calculate the camera/phone's position (translation/rotation) relative to the marker image.
The effect you are looking for is image tracking and rendering within a video feed. You should consider OpenCV for the feature point tracking, or some computer vision library. With regard to rendering there's three options SceneKit, Metal, or OpenGL. Following Apple's lead you could use SceneKit for the rendering, similar to how ARKit handles the sensor inputs and uses SceneKit for rendering. If you are ambitious and want to control the rendering as well you could use Metal or OpenGL.
I currently have a WebCamera that captures video and recognizes the surface of a book and estimates the homography with OpenCV.
(I followed the tutorial at https://bitesofcode.wordpress.com/2017/09/12/augmented-reality-with-python-and-opencv-part-1/
and I rewrote the first part for Unity).
Now I'm wondering how would I go about projecting a 3D model in Unity to the raw image?
I am a total newbie in Unity.
You need to have a Camera (that obviously is directed to your object) which is rendered onto a RenderTexture.
Then add a RawImage to your UI and set the reference to your RenderTexture
I am not an ios developer but my client wants me to make an iphone app like
https://itunes.apple.com/us/app/trippy-booth-amazing-filterswarps/id448037560?mt=8
I have seen some custom library like
https://github.com/BradLarson/GPUImage
but do not find any camera lens customization example.
any kind of suggestions would be helpful
Thanks in advance
You can do it through some custom shader written in OpenGL(or metal just for iOS), then you can apply your shader to do interesting stuff like the image in above link.
I suggest you take a look at how to use the OpenGL framework in iOS.
Basically the flow would like:
Use whatever framework to capture(even in real time) a image.
Use some framework to modify the image. (The magic occur here)
Use another stuff to present the image.
You should learn how to obtain a OpenGL context, draw a image on it, write a custom shader, apply the shader, get the output, to "distort the image". For real, the hardest part is how to create that "effect" in your mind by describing it using a formula.
This is quite similar to the photoshop mesh warp (Edit->Transform->Warp). Basically you treat your image as a texture and then you render it on to a mesh (Bezier Patch) that is a grid that has been distorted into bezier curves, but you leave the texture coordinates as if it was still a grid. This has the effect of "pulling" the image towards the nodes of the patch. You can use OpenGL (GL_PATCHES) for this; I imagine metal or sceneKit might work as well.
I can't tell from the screen shots but its possible that the examples you reference are actually placing their mesh based on facial recognition. CoreImage has basic facial recognition to give youth out and eye positions which you could use to control some of the nodes in your mesh.
Can anyone help me to detect realtime objects in iPhone camera using OpenCV?
My actual objective is to give an alert to users while an object interfering on a specific location of my application camera view.
My current thinking is to capture an image with respect to my camera overlay view which represents a specific location of my camera view. And then I process that image using OpenCV to detect objects by colors. If there I can identify an object in a specific image. I will give an alert to user in camera overlay itself. I coudn't know how I can detect an object from UIImage.
Please direct me if anyone knows some other good way to achieve my goal. Thanks in advance.
I solved my issue by the following way,
Created an image capture module with AVFoundation classes (AVCaptureSession)
Capturing simultaneous image buffer through a timer working along with camera module.
Processing captured frames to find objects through OpenCV
(Cropping, grayscale, threshold, feature detection etc...)
Referral Link: http://docs.opencv.org/doc/tutorials/tutorials.html
Alerting user through animated camera overlay view
Anyway the detection of objects through image processing is not much accurate. We need to have a object sensor (like a depth sensor in Kinet camera or similar) to detect objects in real scenario in live streaming, or may be we have to create AI for it perfect working.
I saw that someone has made an app that tracks your feet using the camera, so that you can kick a virtual football on your iPhone screen.
How could you do something like this? Does anyone know of any code examples or other information about using the iPhone camera for detecting objects and tracking them?
I just gave a talk at SecondConf where I demonstrated the use of the iPhone's camera to track a colored object using OpenGL ES 2.0 shaders. The post accompanying that talk, including my slides and sample code for all demos can be found here.
The sample application I wrote, whose code can be downloaded from here, is based on an example produced by Apple for demonstrating Core Image at WWDC 2007. That example is described in Chapter 27 of the GPU Gems 3 book.
The basic idea is that you can use custom GLSL shaders to process images from the iPhone camera in realtime, determining which pixels match a target color within a given threshold. Those pixels then have their normalized X,Y coordinates embedded in their red and green color components, while all other pixels are marked as black. The color of the whole frame is then averaged to obtain the centroid of the colored object, which you can track as it moves across the view of the camera.
While this doesn't address the case of tracking a more complex object like a foot, shaders like this should be able to be written that could pick out such a moving object.
As an update to the above, in the two years since I wrote this I've now developed an open source framework that encapsulates OpenGL ES 2.0 shader processing of images and video. One of the recent additions to that is a GPUImageMotionDetector class that processes a scene and detects any kind of motion within it. It will give you back the centroid and intensity of the overall motion it detects as part of a simple callback block. Using this framework to do this should be a lot easier than rolling your own solution.