Скачать или смотреть How to Create OpenCV Matrices with Manual Input

Learn how to manually create OpenCV matrices from your own data for effective image processing. See examples and code snippets to get started!
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Is it Possible to Make OpenCV Matrices with Manual Input?

If you're working with OpenCV and need to store the locations of specific points for functions like cv::fillPoly, you might find yourself wondering how to manually create matrices. In this post, we'll delve into how you can work with custom data in OpenCV matrices using C+ + . We will explore simple methods to convert your point data into a format that OpenCV can easily process.

Understanding the Problem

You might have a multidimensional array holding your point locations, like so:

[[See Video to Reveal this Text or Code Snippet]]

Your goal is to use these points with the cv::fillPoly function, but first, you need to convert your data into an OpenCV matrix. This is where we present effective solutions.

Solutions for Creating OpenCV Matrices

Method 1: Reshape a Flat Array

One of the easiest ways to create an OpenCV matrix from manual input is to start with a flat array and then reshape it. Here's how you can do that:

Create a Flat Array: Use a std::vector to initialize your point data.

Reshape It: Use the reshape method to create a matrix in the desired dimensions.

Here's an example:

[[See Video to Reveal this Text or Code Snippet]]

Note: The ret matrix will act as a wrapper around the data. If you would like to copy the data instead, consider using the following code:

[[See Video to Reveal this Text or Code Snippet]]

Method 2: Using Matrix Initialization Operator

Another efficient way to initialize matrices in OpenCV is by using the << operator together with the Mat_ class. This method allows for a flexible and concise way to input your points directly.

Here's an example of how to implement this:

[[See Video to Reveal this Text or Code Snippet]]

In this example, you create a 4x2 matrix directly with your points. This method is clean and readable, making it easy to understand.

Using Your Matrices with cv::fillPoly

Once you have your matrix created using one of the above methods, you can easily utilize it with the cv::fillPoly() function. Simply pass your new matrix along with any other necessary parameters.

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

Creating OpenCV matrices manually can be accomplished with straightforward methods, allowing you to efficiently handle your point location data. By understanding how to manipulate flat arrays and leverage OpenCV's matrix functionalities, you can streamline your image processing workflow. With these techniques, you're equipped to convert your point data into a usable format for further processing with OpenCV functions like cv::fillPoly.

Feel free to explore these methods and adapt them to fit your specific project needs!