Confusion matrix Computation

Brief Description

Computes the confusion matrix of a classification

Tags

Learning

Long Description

This application computes the confusion matrix of a classification map relative to a ground truth dataset. This ground truth can be given as a raster or a vector data. Only reference and produced pixels with values different from NoData are handled in the calculation of the confusion matrix. The confusion matrix is organized the following way: rows = reference labels, columns = produced labels. In the header of the output file, the reference and produced class labels are ordered according to the rows/columns of the confusion matrix.

Parameters

• Input Image (in): The input classification image.

• Matrix output (out): Filename to store the output matrix (csv format)

• set the output format to contingency table or confusion matrix (format): Choice of the output format as a contingency table for unsupervised algorithmsor confusion matrix for supervised ones.

  • Choice of a confusion matrix as output. (confusionmatrix):

  • Choice of a contingency table as output. (contingencytable):



• Ground truth (ref): Choice of ground truth format

  • Ground truth as a raster image (raster):

    • Input reference image (ref.raster.in): Input image containing the ground truth labels

    • Value for nodata pixels in ref raster (ref.raster.nodata): Label to be treated as no data in ref raster.

  • Ground truth as a vector data file (vector):

    • Input reference vector data (ref.vector.in): Input vector data of the ground truth

    • Field name (ref.vector.field): Field name containing the label values

    • Value for nodata pixels in ref vector (ref.vector.nodata): Label to be treated as no data in ref vector. Please note that this value is always used in vector mode, to generate default values. Please set it to a value that does not correspond to a class label.




• Value for nodata pixels in input image (nodatalabel): Label to be treated as no data in input image

• Available RAM (Mb) (ram): Available memory for processing (in MB)

• Load otb application from xml file (inxml): Load otb application from xml file

• Save otb application to xml file (outxml): Save otb application to xml file

Limitations

None

Authors

OTB-Team

See also

Example of use

• Values for GUIs:

• in: clLabeledImageQB1.tif

• out: ConfusionMatrix.csv

• ref: vector

• ref.vector.in: VectorData_QB1_bis.shp

• ref.vector.field: Class

• ref.vector.nodata: 255

• Command line to execute:

otbcli_ComputeConfusionMatrix -in clLabeledImageQB1.tif -out ConfusionMatrix.csv -ref vector -ref.vector.in VectorData_QB1_bis.shp -ref.vector.field Class -ref.vector.nodata 255