*4.5. Cropping*

The final step of the proposed system carries on ROI detection basing on their area, in order to reduce non-cell regions that can be improperly highlighted. In fact, only regions that have an area included in a specific range (a1, a2) are extracted; range values depend on the image resolution. As explained above, we resized the original images to 1024 × 768 pixels and then determined the range experimentally, setting a1 = 80 and a2 = 250. Examples of the cropped cells after applying this operation are given in Figure 9. Figure 10 shows images of the designed app, and in Figure 11 the software pipeline related to cell extraction is reported.

**Figure 9.** Original image (**left**) and extracted cells (**right**).

**Figure 10.** App home page (**a**), app field gallery (**b**).

**Figure 11.** Cell extraction pipeline with methods—see "detect()" in Appendix B.
