# SegmentationRASA

crowdkit.aggregation.image_segmentation.segmentation_rasa.SegmentationRASA | Source code

SegmentationRASA(
self,
n_iter: int = 10,
tol: float = 1e-05
)


Segmentation RASA — chooses a pixel if sum of weighted votes of each workers' more than 0.5.

Algorithm works iteratively, at each step, the workers are reweighted in proportion to their distances to the current answer estimation. The distance is considered as $1 - IOU$. Modification of the RASA method for texts.

Jiyi Li. A Dataset of Crowdsourced Word Sequences: Collections and Answer Aggregation for Ground Truth Creation. Proceedings of the First Workshop on Aggregating and Analysing Crowdsourced Annotations for NLP, pages 24–28 Hong Kong, China, November 3, 2019. https://doi.org/10.18653/v1/D19-5904

## Parameters Description

Parameters Type Description
n_iter int

A number of iterations.

segmentations_ Series

Tasks' segmentations. A pandas.Series indexed by task such that labels.loc[task] is the tasks's aggregated segmentation.

Examples:

import numpy as np
import pandas as pd
from crowdkit.aggregation import SegmentationRASA
df = pd.DataFrame(
[
['t1', 'p1', np.array([[1, 0], [1, 1]])],
['t1', 'p2', np.array([[0, 1], [1, 1]])],
['t1', 'p3', np.array([[0, 1], [1, 1]])]
],