[WIP] update benchmark script

[johnnychen94]

The current benchmark script is broken, so I redesign it. Hopefully, we can catch a bunch of performance bottleneck with it, and decide where the future efforts should be put on.

A comprehensive benchmark on ImageFiltering requires more utils and benchmark items, but I'd like to get some early feedback on this.

I plan to make the benchmark script a little bit redundancy so that we can get more performance information about ImageFiltering. However, this requires quite a long-running time on the local machine (e.g., ~4mins in i7-6700K CPU @ 4.00GHz in the first commit)

TODO:

• [ ] imfilter
  • [ ] algorithm specification
  • [ ] computational resource specification
  • [ ] kernel: separable or not
• [ ] mapwindow
• [ ] visualization of benchmark results
• [ ] easy-to-use benchmarking pipeline script

[johnnychen94]

I completely forget about it. Close in favor of #158