about get range of Mat

[4714407]

I want to use javacv to implement the following C + + code, but I don't know how to write about range. Can you give me some guidance?

std::vector<cv::Range> batchRange{ cv::Range(0, 1), cv::Range::all(), cv::Range::all() };
cv::Mat mat1 = outputMat(batchRange).reshape(0, { outputMat.size[1], outputMat.size[2] });

[saudet]

Which part are you having problems with?

[4714407]

I don't know how to implement outputmat (batchrange)，C + + overloads the () operator here, and then takes out the submatrix through the () operator. I don't know how to do that in javacv

[saudet]

That would be Mat.apply(): http://bytedeco.org/javacpp-presets/opencv/apidocs/org/bytedeco/opencv/opencv_core/Mat.html#apply-org.bytedeco.opencv.opencv_core.Range-

[4714407]

I found that there is a submat method on class org.opencv.core.Mat to implement this transformation, but it seems that there is no submat method on class org.bytedeco.opencv.opencv_core.Mat?

[4714407]

ohh~,Let me have a try!

[4714407]

How to construct a range of three dimensions is similar to the following code:
std::vectorcv::Range batchRange{ cv::Range(0, 1), cv::Range::all(), cv::Range::all() };

[saudet]

We don't need a std::vector, just use an array.

[4714407]

Range ranges=new Range();
            ranges.put(new Range(0,1));
            ranges.put(Range.all());
            ranges.put(Range.all());

Like this?

[4714407]

How can I generate a range array

[saudet]

Almost, something like this: bytedeco/javacpp-presets#824 (comment)

For convenience though, I've also added a RangeVector in commit bytedeco/javacpp-presets@ce0ceca.
Please give it a try with the snapshots: http://bytedeco.org/builds/

[4714407]

Range ranges=new Range(3);
            ranges.position(0).put(new Range(0,1));
            ranges.position(1).put(Range.all());
            ranges.position(2).put(Range.all());
            Mat m1=mat1.apply(ranges)；

Is that right?

[saudet]

No, you forgot the last call to position(0).

[4714407]

Thank you. It's working!