passessfragmentationconsistency

Synopsis

Description

The operator passessfragmentationconsistency calculates 2 errors to assess region fragmentation consistency of a segmentation result by comparison with a reference segmentation.

The two errors are:

• Under-segmentation error accounts for proportion of regions grouped into a single segment.
• Over-segmentation error accounts for proportion of segments grouped into a single region.

A segment S detects a region R if the overlapping area | R * S | is such that:

  | R * S |                                   | R * S |    
  --------- >= matching_threshold and  --------- >= matching_threshold
    | R |                                       | S |

Error values are real values. An under-segmentation error of x means that the segments merge 2^x regions in average assuming that these regions have all the same size. An over-segmentation error of x means that the regions are split into 2^x segments in average assuming that these segments have all the same size. The result is stored in the output collection col_out.

Parameters

• matching_threshold: minimum proportion of overlapping area between a region and a segment to accept a detection. The value is in the interval [0,1] where value x corresponds to a minimum of (x*100)% overlapping.

Inputs

• segmentation_result_in : a region map with segmentation result.
• reference_segmentation_in : a region map with reference segmentation.

Outputs

• col_out: a collection with the 2 error values.

Result

Returns SUCCESS or FAILURE.

Examples

Assesses region fragmentation consistency of the segmentation result stored in 'tangram.pan' considering a minimum overlapping area of 50%:

passessdetectionaccuracy 0.5 resultimages/algo001/tangram.pan groundtruths/expert001/tangram.pan errors.pan
pvisu errors.pan

See also

Prototype C++