# gdal_edit

Edit in place various information of an existing GDAL dataset.

## Synopsis

    gdal_edit [--help-general] [-ro] [-a_srs srs_def]
            [-a_ullr ulx uly lrx lry] [-a_ulurll ulx uly urx ury llx lly]
            [-tr xres yres] [-unsetgt] [-unsetrpc] [-a_nodata value] [-unsetnodata]
            [-unsetstats] [-stats] [-approx_stats]
            [-setstats min max mean stddev]
            [-scale value] [-offset value] [-units value]
            [-colorinterp_X red|green|blue|alpha|gray|undefined]*
            [-gcp pixel line easting northing [elevation]]*
            [-unsetmd] [-oo NAME=VALUE]* [-mo "META-TAG=VALUE"]*  datasetname

## Description

The gdal_edit.py script can be used to edit in place various information of an existing GDAL dataset (projection, geotransform, nodata, metadata).

It works only with raster formats that support update access to existing datasets.

Caution

Depending on the format, older values of the updated information might still be found in the file in a “ghost” state, even if no longer accessible through the GDAL API. This is for example the case of the GTiff – GeoTIFF File Format format (this is not a exhaustive list).

`--help-general```

  Gives a brief usage message for the generic GDAL commandline options and exit.

`-ro```

  Open the dataset in read-only. Might be useful for drivers refusing to use the dataset in update-mode. In which case, updated information will go into PAM `.aux.xml` files.

`-a_srs``<srs_def>`

  Defines the target coordinate system. This coordinate system will be written to the dataset. If the empty string or None is specified, then the existing coordinate system will be removed (for TIFF/GeoTIFF, might not be well supported besides that).

`-a_ullr` `ulx uly lrx lry:`

  Assign/override the georeferenced bounds of the dataset.

`-a_ulurll` `ulx uly urx ury llx lly:`

  Assign/override the georeferenced bounds of the dataset from three points: upper-left, upper-right and lower-left. Unlike `-a_ullr`, this also supports rotated datasets (edges not parallel to coordinate system axes).

  New in version 3.1.

`-tr``<xres> <yres>`

  Set target resolution. The values must be expressed in georeferenced units. Both must be positive values.

`-unsetgt```

  Remove the georeference information.

`-unsetrpc```

  Remove RPC information.

  New in version 2.4.

`-unsetstats```

  Remove band statistics information.

  New in version 2.0.

`-stats```

  Calculate and store band statistics.

  New in version 2.0.

`-setstatsmin` `max mean stddev`

  Store user-defined values for band statistics (minimum, maximum, mean and standard deviation). If any of the values is set to None, the real statistics are calclulated from the file and the ones set to None are used from the real statistics.

  New in version 2.4.

`-approx_stats```

  Calculate and store approximate band statistics.

  New in version 2.0.

`-a_nodata``<value>`

  Assign a specified nodata value to output bands.

`-unsetnodata```

  Remove existing nodata values.

  New in version 2.1.

`-scale``<value>`

  Assign a specified scale value to output bands. If a single scale value is provided it will be set for all bands. Alternatively one scale value per band can be provided, in which case the number of scale values must match the number of bands. If no scale is needed, it it recommended to set the value to 1. Scale and Offset are generally used together. For example, scale and offset might be used to store elevations in a unsigned 16bit integer file with a precision of 0.1, and starting from -100. True values would be calculated as: true_value = (pixel_value * scale) + offset

  Note

  These values can be applied using -unscale during a gdal_translate run.

  New in version 2.2.

`-offset``<value>`

  Assign a specified offset value to output bands. If a single offset value is provided it will be set for all bands. Alternatively one offset value per band can be provided, in which case the number of offset values must match the number of bands. If no offset is needed, it recommended to set the value to 0. For more see scale.

  New in version 2.2.

`-units``<value>`

  Assign a unit to output band(s).

  New in version 3.1.

`colorinterp_X` `red|green|blue|alpha|gray|undefined`

  Change the color interpretation of band X (where X is a valid band number, starting at 1).

  New in version 2.3.

`-gcp` `pixel line easting northing [elevation]`

  Add the indicated ground control point to the dataset. This option may be provided multiple times to provide a set of GCPs.

`-unsetmd```

  Remove existing metadata (in the default metadata domain). Can be combined with `-mo`.

  New in version 2.0.

`-mo` `META-TAG=VALUE`

  Passes a metadata key and value to set on the output dataset if possible. This metadata is added to the existing metadata items, unless `-unsetmd` is also specified.

`-oo` `NAME=VALUE`

  Open option (format specific).

  New in version 2.0.

The `-a_ullr`, `-a_ulurll`, `-tr` and `-unsetgt` options are exclusive.

The `-unsetstats` and either `-stats` or `-approx_stats` options are exclusive.

## Example

    gdal_edit -mo DATUM=WGS84 -mo PROJ=GEODETIC -a_ullr 7 47 8 46 test.ecw

    gdal_edit -scale 1e3 1e4 -offset 0 10 twoBand.tif