A change in overlap setting

[Zhengdi Liu]

Hi everyone,

I made a change for overlap logical validation condition.

The previous condition:

if overlap[0] >= window_size[0] or overlap[1] >= window_size[1]:
        raise ValueError("Overlap has to be smaller than the window_size")

The changed condition:

if overlap[0] >= search_area_size[0] or overlap[1] >= search_area_size[1]:
        raise ValueError("Overlap has to be smaller than the search_area_size")

By changing the condition to require overlap to be smaller than search_area_size, the spacing between window centers can be adjusted more flexibly, allowing overlaps up to search_area_size - 1. This changing allows create an one-pixel-dense velocity field when the search_area_size is larger than window_size. More detailed examples and usages can be found at https://github.com/OpenPIV/openpiv-python/blob/master/openpiv/tutorials/Example%20for%20overlap%20setting%20change.ipynb. Please tell me if you have any question about this.

Regards,

Zhengdi