OpenCV Vec4iVector should be built on IntPointer

[jpsacha]

In C++ code Vec4i is defined as a vector of integers:

typedef Vec<int, 4> cv::Vec4i

In org.bytedeco.opencv.presets.opencv_imgproc (line 53) it is defined based on FloatPointer:

new Info(..., "cv::Vec4i", ...).cast().pointerTypes("FloatPointer"))

it should be rather:

new Info("cv::Vec4i").cast().pointerTypes("IntPointer"))

A problem with current implementation can be seen when using HoughLinesP. It will produce lines' coordinates as Vec4i. Those coordinates of lines cannot be correctly transferred from the C++ side.

[saudet]

Yes, that's an error that slipped there. In any case, to work around that with the current release, we can easily cast to IntPointer to access it properly.

[jpsacha]

Not clear how workaround with casting to IntPointer should be done.

Here is some sample code that is using HoughLinesP to get line fragments(lines):

Vec4iVector lines = new Vec4iVector()
HoughLinesP(binary, lines, deltaRho, deltaTheta, minVotes, minLength, minGap)
FloatPointer l = lines.get(i)
float x1 = l.get(0)

Due to the bug, the value of x1 is not extracted correctly. Where the casting to IntPointer should happen?

[saudet]

Something like this:

IntPointer l = new IntPointer(lines.get(i));
int x1 = l.get(0);

[jpsacha]

The workaround works. I added it to the LineFinder example.

[saudet]

Fix included in version 1.5.1. Thanks for reporting!