I am wondering there must be a way to get a depth of image. Certainly some portions can be extruded so that we get 3d version of 2d image. Any sources that will help in this out.
FYI: I would like to get point cloud from 2d image.
Thank you in advance..
Reconstruction from single 2D image is not possible. As mentioned by others, there is loads of literature to refer to. Multi-View Geometry by Hartely and Zisserman can be a good start. An example tutorial to start with: Reconstruction. you can also refer to computer vision toolbox from matlab/opencv
It is possible to draw some 3D information from a 2D image.
There are methods to extract depth infortmation from the blur of a pixel. When a picture is captured, you focus in one place and let remaining portion blur, and hence blur captures depth.
See Make3d project to startwith.
Thank you.
Related
How to detect such cracks that you can see in the attached images? I have tried some OpenCV algorithms like blob detection (cv::SimpleBlobDetector) but couldn't get any results.
It is a cropped image, the full image has some other features as well, so I am not sure thresholding can work because I have to get the bounding box of the detected crack. One way is to assign several (region of interest) ROI and try to detect within that ROI, but this crack doesn't appear at the same location in the image. Any idea?
Can this problem be solved with machine/deep learning (like object detection)? If I train a model with a crack dataset? Because the crack part of the image doesn't have lots of features so I am not sure this method will work. Please guide.
Thanks.
These cracks are difficult to detect because the image is noisy (presumably X-ray) and the contrast poor, so the signal-to-noise ratio is low.
I would try by applying a gaussian filter for denoising, but only in the horizontal direction, to preserve the horizontal edges. Then detection of the horizontal edges.
This is about what a Gabor filter does. You can try different orientations.
Use mathematical morphology operation.
By example Matlab code:
a=imread('in.png');
se=strel( 'disk', 7);
b = imgaussfilt(a,1.3);
c=b-imopen(b,se);
c=3*c;
d=imclearborder(c);
imwrite(d, 'out.png');
I'm creating a 3D map with 2D depth images in Processing. I have captured the images using saveFrame(), however I am having difficulty in converting those saved frames into 3D. Is there any website or code I could look through for help? Any help would be much appreciated.
Before i'm going to go in-depth into your question, i want to mention that instead of saveFrame() you can use the standard dfx library to export 3d models instead of 2d images using Processing if you simply want to store a scene:
https://processing.org/reference/libraries/dxf/
Now back to your question. First of all what are depth images? Are those simply saveFrames from a 3D Scene in Processing (P3D) or are these special images, because depth is quite a general term. If they are 3D Scenes and you would know the coordinates of the camera and their viewangle the task gets quite easier, but it is technically impossible to create a 3D object using only 2D images without XRay. Imagine looking at a fork. Your eyes are making 2 pictures of that fork, however you have no idea what might be inscribed on the back of that fork. No matter how many pictures you might have of your 3D scene, you won't be able to convert it into 3D perfectly. That said, this is indeed a general problem in computer science and there are various methods to solve this. Wikipedia has an article on it:
http://en.wikipedia.org/wiki/3D_reconstruction_from_multiple_images
http://en.wikipedia.org/wiki/2D_to_3D_conversion
Here are a few stackoverflow topics which might help you get started:
3d model construction using multiple images from multiple points (kinect)
How to create 3D model from 2D image
Converting several 2D images into 3D model
i am going to develope a system which will take a 2D still image as a input & 3D image as a output.
So the steps are:
1. creating a depth map from 2D image
2. creating 3D image from depth map and original image.
Can anybody suggest me the algorithms to generate the depth map of 2D image?
As far as I know, there's no 100% bullet proof algorithm that can convert a 2D image to a 3D model. Simply said, there's not enough information inside a 2D image to fully construct something 3D. Some 3D TV sets manage to do some fake 3D from the 2D input but nothing really convincing (and sometimes wrong.)
What famous softwares do (like the one in the Kinect), is use several sources instead of one single 2D image. With pictures from different angles, you can track some particular features in the images and with geometric computations output something 3D. See http://en.wikipedia.org/wiki/3D_reconstruction_from_multiple_images for full explanation.
If you're stuck with a single image, the best known tool is the human eye... Humans can easily reconstruct 3D from a picture, by unconsciously merging several factors, such as their experience of the scene, the focus blur, "far-away fog effect", etc... So the best way for you to have a result, is to do the depth map yourself in any image editing software...
Julien
is it possible to construct a 3d model of a still object if various images along with depth data was gathered from various angles, what I was thinking was have a sort of a circular conveyor belt where a kinect would be placed and the conveyor belt while the real object that is to be reconstructed in 3d space sits in the middle. The conveyor belt thereafter rotates around the image in a circle and lots of images are captured (perhaps 10 image per second) which would allow the kinect to catch an image from every angle including the depth data, theoretically this is possible. The model would also have to be recreated with the textures.
What I would like to know is whether there are any similar projects/software already available and any links would be appreciated
Whether this is possible within perhaps 6 months
How would I proceed to do this? Such as any similar algorithm you could point me to and such
Thanks,
MilindaD
It is definitely possible and there are a lot of 3D scanners which work out there, with more or less the same principle of stereoscopy.
You probably know this, but just to contextualize: The idea is to get two images from the same point and to use triangulation to compute the 3d coordinates of the point in your scene. Although this is quite easy, the big issue is to find the correspondence between the points in your 2 images, and this is where you need a good software to extract and recognize similar points.
There is an open-source project called Meshlab for 3d vision, which includes 3d reconstruction* algorithms. I don't know the details of the algorithms, but the software is definitely a good entrance point if you want to play with 3d.
I used to know some other ones, I will try to find them and add them here:
Insight3d
(*Wiki page has no content, redirects to login for editing)
Check out https://bitbucket.org/tobin/kinect-point-cloud-demo/overview which is a code sample for the Kinect for Windows SDK that does specifically this. Currently it uses the bitmaps captured by the depth sensor, and iterates through the byte array to create a point cloud in a PLY format that can read by MeshLab. The next stage of us is to apply/refine a delanunay triangle algoirthim to form a mesh instead of points, which a texture can be applied. A third stage would then me a mesh merging formula to combine multiple caputres from the Kinect to form a full 3D object mesh.
This is based on some work I done in June using Kinect for the purposes of 3D printing capture.
The .NET code in this source code repository will however get you started with what you want to achieve.
Autodesk has a piece of software that will do what you are asking for it is called "Photofly". It is currently in the labs section. Using a series of images taken from multiple angles the 3d geometry is created and then photo mapped with your images to create the scene.
If you interested more in theoretical (i mean if you want to know how) part of this problem,
here is some document from Microsoft Research about moving depth camera and 3D reconstruction.
Try out VisualSfM (http://ccwu.me/vsfm/) by Changchang Wu (http://ccwu.me/)
It takes multiple images from different angles of the scene and outputs a 3D point cloud.
The algorithm is called "Structure from Motion".
Brief idea of the algorithm : It involves extracting feature points in each image; finding correspondences between them across images; building feature tracks, estimating camera matrices and thereby the 3D coordinates of the feature points.
I have a set of Points in 3D space.
The image below is an example:
I would like to turn these points into a surface. I just know the X,Y and Z values of the points.
For example, check out the image below, which shows a mesh of a human face generated from points in 3D space.
i googled so much but, what i found is some images and explaination
but no one has explained with practical aspect and practical example.
is there any good or best algorithms which help me to solve this problem.
Please....
Thaks...........
You want to do a Delaunay-Triangulation. See example application here: http://www.geometrylab.de/VoroGlide/.