# 5.1 Combining Fractured Grains

Here is our optical image:

In optical image, it is obvious that some grains are with stripes on their surface. These stripes may mislead the watershed segmentation by seperating a grain into several segmentation. In this case, users need to use red marker to combine these segments.

- Let's take this grain for example

- After initial segmentation, the grain is segmented into several pieces.

- In this case, we recommend users to briefly fill up the whole grain with red marker. (Turn off "Segment Overlay")

- Then these segments will merge together

- Finally, let's seperate the other grains from this segment by drawing red marker on the other grains and clicking "ReSegment".
(Turn off "Marker Overlay")