Full fill a rectangle shape in an image

Hi,

I'm processing an image (please see attachment).

I tried to full fill the white rectangle (which is currently covered by the water drop shaped black shadow).

How can I remove the shadow to get the fully rectange?

I have the Boundary polyshape of white shape.

This is the polyshape I have:

And the image:

Thanks

[rough93]

Create a vector between two points on the left edge above and below the drop, create a for loop for every row between column to the right to color it your chosen color. You can set additional paramters to limit how much is colored.

[Le Vu Bao]

Yes, I thought about this approach. I tried to detect 2 upper and lower points of the drop. But the corner detector in Matlab returned far more points (7 corners is the lowest). Not until I can detect these 2 points I think cannot continue this solution.

Could you give more detail way to detect these two points out of other corner points?

Although, I finally completed my goal using boundary function. I am really curious how to get it done in this way

Answer 1

[darova]

Use convhull or boundary to get contour of your figure

Then use inpolygon to fill this shape

[Le Vu Bao]

Thanks, I used boundary function and It worked like a charm