pkdiff(1)

NAME

pkdiff - program to compare two raster image files

SYNOPSIS

FCpkdiffF[0] FC-iF[0] input FC-refF[0] 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 FC-cmF[0]|FC--confusionF[0] 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

FC-iF[0] filename, FC--inputF[0] filename

Input raster dataset.

FC-refF[0] filename, FC--referenceF[0] filename

Reference (raster or vector) dataset

FC-lnF[0] layer, FC--lnF[0] layer

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

FC-bF[0] band, FC--bandF[0] band

Input raster band

FC-cmF[0], FC--confusionF[0]

Create confusion matrix (to stdout)

FC-lrF[0] attribute, FC--lrefF[0] attribute

Attribute name of the reference label (for vector reference datasets only)

FC-cF[0] name, FC--classF[0] name

List of class names.

FC-rF[0] value, FC--reclassF[0] value

List of class values (use same order as in classname option).

FC-nodataF[0] value, FC--nodataF[0] value

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

FC-mF[0] mask, FC--maskF[0] mask

Use the first band of the specified file as a validity mask. Nodata values can be set with the option FC--msknodataF[0].

FC-msknodataF[0] value, FC--msknodataF[0] value

Mask value(s) where image is invalid. Use negative value for valid data (example: use FC-tF[0] FC-1F[0]: if only FC-1F[0] is valid value)

FC-vF[0] level, FC--verboseF[0] level

verbose level

Advanced options

FC-oF[0] output, FC--outputF[0] output

Output dataset (optional)

FC-fF[0] OGRformat, FC--fF[0] OGRformat

OGR format for output vector (for vector reference datasets only)

FC-ofF[0] GDALformat, FC--oformatF[0] GDALformat

Output image format (see also gdal_translate(1)). Empty string: inherit from input image

FC-lcF[0] attribute, FC--lclassF[0] attribute

Attribute name of the classified label (for vector reference datasets only)

FC--commissionF[0] value

Value for commission errors: input label < reference label

FC-bndF[0] value, FC--boundaryF[0] value

Boundary for selecting the sample (for vector reference datasets only)

FC-homF[0], FC--homogeneousF[0]

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

FC-circF[0], FC--circularF[0]

Use circular boundary (for vector reference datasets only)

FC-ctF[0] colortable, FC--ctF[0] colortable

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

FC-coF[0] NAME=VALUE, FC--coF[0] 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)

FC
pkdiff -i input.tif -ref reference.tif
      F[0]

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

FC
pkdiff -i classificationMap.tif -ref referencePoints.tif -cm
      F[0]