I'd like to know how to plot a wave function u(x,t), which is defined on spatial domain x and temporal domain t by using wxMaxima. Please help me with the code if we set x=[-5:5], t=[0:10] and we would like the function to be plotted and moved temporally in one figure?
For example, let u(x,t)=sin(x+t).
Thank you.
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Hi I'm currently trying to implement a stereo matching algorithm in c and I'm having trouble to understand a part in the
paper.
My Problem is the part after the subpixel calculation on page 17. I don't understand it how to get the subpixel disparity map for both directions. Also I'm a little bit confused if my cost aggregation is correct. It's recommended to use a 5x5 windows and sum the values over this block. Do I sum all values in this 5x5 block or do I add every second in every second row, like I did for the census transformation? Thanks for the help!
I have an array of MKLocationCoordinate2D in iOS and I'd like to create a heat map of those points based on the clustering of them.
i.e. the more there are in a certain area then the higher the weight.
I've found a load of different frameworks for generating the heat maps and they all require the weights to be calculated yourself (which makes sense).
I'm just not sure where to start with the calculation.
I could do something like calculating the mean distance between each point and every other point but I'm not sure if that's a good idea.
Could someone point me in the direction of how to weight each point based on it's closeness to other points.
Thanks
I solved this by implementing a quad tree and using that to quickly get the number of neighbours within a certain radius.
I can then change the radius to tweak it but it will very quickly return weights based on how many neighbours each point has.
I want to find curvature at depth map
Look at the picture
This is example of curvature
Maybe if i represent image as function and take second derivative from it a can find curvatures. But i couldn't to implement it. (I tryed sobel operator from opencv)
Is there way out?
PS Sorry for my writing mistakes. English in not my native language.
That is not a depth map, it is a point cloud (but I assume it is generated from one single depth map z = f(x,y).
What curvature do you want to estimate? Mean, Gaussian, the whole 2nd fundamental form?
See, e.g. here for definitions. Here's a recent reference on fast estimation methods:
After been able to calculate shortest distance using Dijstra algorithm feeding manually vertex point (getting lat and long from google maps) I'm searching a more dynamic way to do the same.
Assuming I'm having a shape file representing my map (with boundaries and obstacles) which algorithm I can use to decompose it?
Googling a little bit I found I should do a "cell decomposition" but honestly I've not figured out how to do it?
Thank you.
If you only have obstacles in shape file, than you could construct visibility graph, and use dijkstra on that.
If you have regions with different passabilities, than you should use some more complicated techniques, for example overlay it with some grid(rectangualr or triangular), than triangulate, assign weights to it's edges, and than use dijkstra too
Can anyone tell me of a method to refine disparity maps? I am trying to generate the disparity map of a face but the features like eyes, nose ,lips etc are not clear.How can I refine it to make it look better?
Take a look at
https://code.ros.org/trac/opencv/browser/trunk/opencv/samples/cpp/stereo_match.cpp
there are some bm.state parameters (about line 197 - 207) that can be tweaked, we connected those values to some sliders so we could look at the result at the same time as we tweaked the values. you can also try with some different values for "blocksize". you can also try with some different distances between your cameras, if the cameras are too far apart, you will get poor / no results on close distances.
I assume that your code is similar to the example above.
Use stereoSGBM I am using it and you can use trackbars to tweak the parameters study the refernece of opencv and then manipulate each parameter based on the effect it has on your image eg:P1 P2 make it smoother etc