NAME

       pkdiff - program to compare two raster image files

SYNOPSIS

       pkdiff -i input -ref reference [options] [advanced options]

DESCRIPTION

       pkdiff  compares  two datasets.  The reference can either be a raster or a vector, but the
       input must be a raster dataset.  In case the reference is a raster  dataset,  a  pixel  by
       pixel  comparison  is  performed.   With  no  further  options, the utility reports if the
       rasters are identical or different.  If required, an output raster dataset can be  written
       with  a  qualitative  information per pixel: 0 (input=reference), 1 (input>reference) or 2
       (input<reference).  If, however, the reference is a vector dataset,  it  must  consist  of
       point  features.   Polygon  features  are  automatically  converted to the centroid points
       before analyzing.

       A typical use of the utility is to assess the accuracy of an input raster land cover  map,
       based  on  a  reference  vector  dataset.  The reference dataset must contain an attribute
       (label) for each class.  A confusion matrix is produced if the option  -cm|--confusion  is
       set.   Here  too, an output dataset can be written, which will be a vector dataset in this
       case.  It contains the reference feature points with  the  extracted  data  value  of  the
       raster input dataset as a new attribute.

OPTIONS

       -i filename, --input filename
              Input raster dataset.

       -ref filename, --reference filename
              Reference (raster or vector) dataset

       -ln layer, --ln layer
              Layer  name(s) in sample.  Leave empty to select all (for vector reference datasets
              only)

       -b band, --band band
              Input raster band

       -cm, --confusion
              Create confusion matrix (to stdout)

       -lr attribute, --lref attribute
              Attribute name of the reference label (for vector reference datasets only)

       -c name, --class name
              List of class names.

       -r value, --reclass value
              List of class values (use same order as in classname option).

       -nodata value, --nodata value
              No data value(s) in input or reference dataset are ignored

       -m mask, --mask mask
              Use the first band of the specified file as a validity mask.  Nodata values can  be
              set with the option --msknodata.

       -msknodata value, --msknodata value
              Mask  value(s) where image is invalid.  Use negative value for valid data (example:
              use -t -1: if only -1 is valid value)

       -v level, --verbose level
              verbose level

       Advanced options

       -o output, --output output
              Output dataset (optional)

       -f OGRformat, --f OGRformat
              OGR format for output vector (for vector reference datasets only)

       -of GDALformat, --oformat GDALformat
              Output image format (see also gdal_translate(1)).  Empty string: inherit from input
              image

       -lc attribute, --lclass attribute
              Attribute name of the classified label (for vector reference datasets only)

       --commission value
              Value for commission errors: input label < reference label

       -bnd value, --boundary value
              Boundary for selecting the sample (for vector reference datasets only)

       -hom, --homogeneous
              Only  take  regions  with homogeneous boundary into account (for reference datasets
              only)

       -circ, --circular
              Use circular boundary (for vector reference datasets only)

       -ct colortable, --ct colortable
              Color table in ASCII format having 5 columns: id R G B ALFA (0:  transparent,  255:
              solid).

       -co NAME=VALUE, --co NAME=VALUE
              Creation option for output file.  Multiple options can be specified.

EXAMPLE

       Check if two raster images are different (reports only if images are different or not)

       pkdiff -i input.tif -ref reference.tif

       Validate  a  classification  map using points from a reference sample and report confusion
       matrix

       pkdiff -i classificationMap.tif -ref referencePoints.tif -cm

                                           27 June 2023                                 pkdiff(1)