program to mosaic and composite geo-referenced images

SYNOPSIS

Usage: pkcomposite -i input [-i input]* -o output

Options: [-b band]* [-dx xres] [-dy yres] [-e vector] [-ulx ULX -uly ULY -lrx LRX -lry LRY] [-cr rule] [-cb band] [-srcnodata value] [-bndnodata band] [-min value] [-max value] [-dstnodata value] [-r resampling_method] [-ot {Byte / Int16 / UInt16 / UInt32 / Int32 / Float32 / Float64 / CInt16 / CInt32 / CFloat32 / CFloat64}] [-of format] [-co NAME=VALUE]* [-a_srs epsg:number]

Advanced options: [-file] [-w weight]* [-c class]* [-ct colortable] [-d description] [-align]

Description

The utility pkcomposite can be used to mosaic and composite multiple (georeferenced) raster datasets. A mosaic can merge images with different geographical extents into a single larger image. Compositing resolves the overlapping pixels according to some rule (e.g, the median of all overlapping pixels). This utility is complementary to GDAL, which currently does not support a composite step. Input datasets can have different bounding boxes and spatial resolutionsresolution.

composite rule	composite output
overwrite	Overwrite overlapping pixels: the latter input image on the command line overrules the previous image
maxndvi	Create a maximum NDVI (normalized difference vegetation index) composite from multi-band input images. Use option -cb to set the indexes of the red and near infrared bands respectively (e.g., -cb 0 -cb 1)
maxband	Select the pixel with a maximum value in the band specified by option -cb
minband	Select the pixel with a minimum value in the band specified by option -cb
mean	Calculate the mean (average) of overlapping pixels
stdev	Calculate the standard deviation of overlapping pixels
median	Calculate the median of overlapping pixels
mode	Select the mode of overlapping pixels (maximum voting): use for Byte images only
sum	Calculate the arithmetic sum of overlapping pixels
maxallbands	For each individual band, assign the maximum value found in all overlapping pixels. Unlike maxband, output band values cannot be attributed to a single (date) pixel in the input time series
minallbands	For each individual band, assign the minimum value found in all overlapping pixels. Unlike minband, output band values cannot be attributed to a single (date) pixel in the input time series

Example: Calculate the maximum NDVI composite of two multispectral input images (e.g., red is band 0 and near infrared is band 1)

pkcomposite -i input1.tif -i input2.tif -o output.tif -cr maxndvi -cb 0 -cb 1

Example: Calculate the minimum nadir composite of two input images, where the forth band (b=3) contains the view zenith angle

pkcomposite -i input1.tif -i input2.tif -o minzenith.tif -cr minband -cb 3

Example: Calculate the minimum of two input images in all bands

pkcomposite -i input1.tif -i input2.tif -o minimum.tif -cr minallbands

Options

use either -short or --long options (both --long=value and --long value are supported)
short option -h shows basic options only, long option --help shows all options

short	long	type	default	description
i	input	std::string		Input image file(s). If input contains multiple images, a multi-band output is created
o	output	std::string		Output image file
b	band	int		band index(es) to crop (leave empty if all bands must be retained)
dx	dx	double		Output resolution in x (in meter) (empty: keep original resolution)
dy	dy	double		Output resolution in y (in meter) (empty: keep original resolution)
e	extent	std::string		get boundary from extent from polygons in vector file
cut	crop_to_cutline	bool	false	Crop the extent of the target dataset to the extent of the cutline
eo	eo	std::string		special extent options controlling rasterization: ATTRIBUTE or CHUNKYSIZE or ALL_TOUCHED or BURN_VALUE_FROM or MERGE_ALG, e.g., -eo ATTRIBUTE=fieldname
m	mask	std::string		Use the first band of the specified file as a validity mask (0 is nodata)
msknodata	msknodata	float	0	Mask value not to consider for composite
mskband	mskband	short	0	Mask band to read (0 indexed)
ulx	ulx	double	0	Upper left x value bounding box
uly	uly	double	0	Upper left y value bounding box
lrx	lrx	double	0	Lower right x value bounding box
lry	lry	double	0	Lower right y value bounding box
cr	crule	std::string	overwrite	Composite rule (overwrite, maxndvi, maxband, minband, mean, mode (only for byte images), median, sum, maxallbands, minallbands, stdev
cb	cband	int	0	band index used for the composite rule (e.g., for ndvi, use –cband=0 –cband=1 with 0 and 1 indices for red and nir band respectively
srcnodata	srcnodata	double		invalid value(s) for input raster dataset
bndnodata	bndnodata	int	0	Band(s) in input image to check if pixel is valid (used for srcnodata, min and max options)
min	min	double		flag values smaller or equal to this value as invalid.
max	max	double		flag values larger or equal to this value as invalid.
dstnodata	dstnodata	double	0	nodata value to put in output raster dataset if not valid or out of bounds.
r	resampling-method	std::string	near	Resampling method (near: nearest neighbor, bilinear: bi-linear interpolation).
ot	otype	std::string		Data type for output image ({Byte/Int16/UInt16/UInt32/Int32/Float32/Float64/CInt16/CInt32/CFloat32/CFloat64}). Empty string: inherit type from input image
of	oformat	std::string	GTiff	Output image format (see also gdal_translate).
co	co	std::string		Creation option for output file. Multiple options can be specified.
a_srs	a_srs	std::string		Override the spatial reference for the output file (leave blank to copy from input file, use epsg:3035 to use European projection and force to European grid
file	file	short	0	write number of observations (1) or sequence nr of selected file (2) for each pixels as additional layer in composite
w	weight	short	1	Weights (type: short) for the composite, use one weight for each input file in same order as input files are provided). Use value 1 for equal weights.
c	class	short	0	classes for multi-band output image: each band represents the number of observations for one specific class. Use value 0 for no multi-band output image.
ct	ct	std::string		color table file with 5 columns: id R G B ALFA (0: transparent, 255: solid)
align	align	bool		Align output bounding box to first input image
scale	scale	double		output=scale*input+offset
off	offset	double		output=scale*input+offset
d	description	std::string		Set image description

Examples

Some examples how to use pkcomposite can be found here

FAQ

Frequently asked questions on pkcomposite can be found here