uavimg_worldfile: Create world and projection files for UAV images
In UCANR-IGIS/uavimg: Drone Image Utilities

Description Usage Arguments Details Value See Also

View source: R/uavimg_worldfile.R

Create world files and projection files for UAV images

1 2	uavimg_worldfile(x, aux.xml = TRUE, wld = FALSE, wldext = "auto", prj = FALSE, rotated = TRUE, quiet = FALSE)

`x`	A list of class 'uavimg_info'
`aux.xml`	Create an aux.xml file, logical. See details.
`wld`	Create a world file, logical. See details.
`wldext`	Extension for the world file, character. Ignored if `wld = FALSE`.
`prj`	Create a prj file, logical. See details.
`rotated`	Compute parameters that replicate the camera Yaw.
`quiet`	Show messages.

This function creates sidecard world files and/or projection files that are required to view raw images in GIS software such as ArcGIS and QGIS.

Note: this function has been tested with JPG files from several DJI cameras. It has not yet been adapted for TIF files from multispectral cameras, and may not work with those format.

Note that the parameters in the world file are taken exclusively from the image metadata, and will be approximate at best. For a more accurate image placement, process the images with photogrammetry software.

If your objective is to open the images in ArcGIS or QGIS, then generating the aux.xml files should be all you need. aux.xml files are ESRI auxillary files for raster layers. To be read by GIS software, they should have the same name as the image file with 'aux.xml' added on. aux.xml files can contain a lot of info about a raster layer, including statistics, the rotation info, coordinate reference system, and other stuff. If generated by this function, they will contain projection and rotation info only. Note also any existing aux.xml files will be overwritten. aux.xml files are the only sidecar file that ArcGIS software supports for reading the projection info.

World files are small text files with extensions jpw and tfw for JPG and TIF files respectively. To be read by GIS software, they must have the same basename as the image and be saved in the same directory. Both ArcGIS and QGIS read world files, however they are not needed if the same info is available in an aux.xml file.

prj files contain just the Coordinate Reference System info. They do not seem to be recognized for rasters by ArcGIS, however QGIS picks them up.

A vector of filenames generated.

uavimg_info

UCANR-IGIS/uavimg documentation built on July 13, 2020, 9:35 p.m.