Help me to learn correlation function in Opencv.
I have read some references but I unable to get a correct idea.
Using Correlation can I match two images and assign weights on them by considering relation between original and another. ?
(becouse I want to match 2 images like same but not 100% same)
Is a kind of Template matching ...?
I wonder if someone can point me a sample code in c++ somewhere in net.
Thank you
You can use Image Correlation to find subimages inside an image.
This is how it works, looking for zeroes inside a textbox:
Also, take a look at this answer
Related
Does anyone know if we can use multiple RegisterTransitCallback for different dimensions in ortools vrp?
What I have noticed in my code shows that only the last RegisterTransitCallback will take effect for all the added dimensions.
I is common to have one callback for time and one for distance. This is shown in vrptw examples.
So yes.
I want to use dataset at https://ingmec.ual.es/datasets/lidar3d-pf-benchmark/ in my project. The available map is .simplemap. What I understand is it stores both map and the robot poses as well. I want to get the point cloud representation of this map (which later I can convert into octomap) as well as vehicles ground truth pose in the map.
I have been able to get the CPose3DPDF from which I obtained CPose3d which I believe is the desired vehicle's ground truth pose. Please correct me if I am wrong. Now I have two problems. First the length of trajectory is just 97 which makes me suspicious about my code to obtain it. Second is about the CSensoryFrame which I obtain along with CPose3DPDF. When I get CObservation by doing CSensorFrame->getObservationByIndex and write to a file, it gives me idea that it stores velodyne readings. But I am unable to recover point cloud from it. Could anyone please guide me to a tool which can convert a .simplemap into a point cloud or an octomap representation and obtain vehicle's pose out of it as well. Many thanks in advance.
For the records: this one was answered here:
Your assumptions were all correct.
I realized the full UAL campus map was not included into the downloads. It's now available to download inside 2018-02-26-ual-campus-map.zip, at the bottom of this dataset page.
You can also regenerate the pointcloud, octomap from the .simplemap using the app application-observations2map.
Example .ini files can be found under MRPT/share/mrpt/config_files/*
You can also visually inspect .simplemap files with the robot-map-gui app.
I am using spatstat package in R to read my road network shapefile which also has some additional attributes.
When i am reading my shapefiles and converting them to as.psp(before I make them an object of linnet), I am getting n columns of data frame discarded. I do not understand why? The columns being discarded are my covariates for a linear network, so I am not able to bring them into my analysis.
Could someone give me an idea why this happens and how to correct it?
Why it happens:
I would guess that we (spatstat authors) need to spend a bit of time discussing with the maptools guys how to handle the additional info in the SpatialLinesDataFrame object, and we haven't done that yet.
How to correct it:
You have to write some code on your own at the moment. You can extract the data from SpatialLinesDataFrame object by accessing the #data slot. Please provide specific data and how you need to use the additional data (what format do you need it in) if you need more help. You can find a few helpful commands here: https://cran.r-project.org/web/packages/spatstat/vignettes/shapefiles.pdf
I am trying to do an image manipulation wherein the user would be prompted to enclose the mouth portion within an image. Once the user does that my application should identify the pixels that would identify the teeth (the color varying from white to yellow) and then I would like to brighten only those pixel. Could anyone give me a guidance on how to proceed?
Your question is quite honestly, very broad as an adequate answer will touch on a large number of areas.
Nevertheless, what you are trying to attempt is called Pattern Recognition. More specifically, your problem is geared towards image-analysis, dealing mainly in Template Matching:
Template matching is a technique in digital image processing for
finding small parts of an image which match a template image. It can
be used in manufacturing as a part of quality control, a way to
navigate a mobile robot, or as a way to detect edges in images.
The Template Matching page has a C-like language sample algorithm which demonstrates what you are attempting to do (identify a specific color within an image).
As for how to go about this, generally speaking you will have to load an image, store it into an array then try to manipulate it as the algorithm suggests:
One way to perform template matching on color images is to decompose
the pixels into their color components and measure the quality of
match between the color template and search image using the sum of the
absolute differences (SAD) computed for each color separately.
Of course, there are numerous projects in various languages that do that for you. My suggestion is to read up a bit more on the topic, pick a language, and attempt a solution using libraries as necessary.
One book that you might find to be very helpful is the classic Phillips: Image Processing in C even if you don't want to use C. Why? Because it pores over a lot of the algorithmic details in how they work, and how to implement them. And, its free too.
I use a library that gives me at the end the vtkpoints. Now I would like to extract points
from them. But all the method available from VTKPoints require point id, which i do not know.
Is there a way of doing it?
I can't offer a definitive answer, since the VTKPoints documentation doesn't discuss the values of the point ids and I don't have any experience with this. However, all of the examples I have seen just use integers in the range [0..NumberOfPoints-1] as the point ids, so it would seem that what you are doing is perfectly reasonable (note, however, that your comment I am using the indexes: 0..NumberOfPoints should be 0..NumberOfPoints-1).
The points are definitely just stored in a vector-like container with sequential indexing from 0 to GetNumberOfPoints()-1.