Tomni

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- Add convert to color

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- Add json2bbox for polygon and ellipse

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- Update Json-circularity with circularity calculation from contour ops.

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- BUGFIX: Import approximate_circle_by_area
- Add roundness
- Add contour operation circularity

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- Add inner contours to labels2contours
- Add inner contours to mask2json

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- Add approximate_circle_by_area to contour operations
- BUGFIX: Change type np.array to np.ndarray
- DEPRECATE: Remove simplification so python 3.8+ can be used