Measure along / within ROIs

Not sure if this is within the scope of the project, but it would be nice to be able to measure along ROIs (e.g. a "profile line" through that moves through space in one (more, eventually?) axis. Through lines, it could be a profile line. With polygons, it could be average intensity (or any other function that takes a set of pixels and returns a number), or a profile line along the circumference of the shape.

Something like this as an example of the profile line:

I worked on something like this a couple of years ago, and might give it a shot when I have the time, but I thought I'd leave this here so I could remember, and if it inspired anyone else to give it a shot since I think it'd be very useful!

issue 中没有指定文件、测试或入口点。首先检查仓库中现有的 ROI 和 plotting 入口点，然后明确线剖面、多边形聚合和周长剖面是否在范围内。只有明确规定了受支持的 ROI 测量及其预期行为，才能视为完成。