====== Transform Map ======

===== Description =====

Reprojects a map file according to a set of parameters. It can also crop and reproject a map based on the projection, extents, and cell size of a given format map. This functor is also known by the alias ''ReprojectMap'' in EGO Script.

===== Inputs =====

^ Name  ^ Type  ^ Description  ^
| Input Map Filename  | [[Map Filename Type]]  | Filename of the input map to reproject.  |
| Output Map Filename  | [[Map Filename Type]]  | Filename of the resulting reprojected map. Its format is selected from the file extension.  |

===== Optional Inputs =====

^ Name  ^ Type  ^ Description  ^ Default Value  ^
| Output Format Map Filename  | [[Map Filename Type]]  | Filename of a format map whose projection, extents, and cell size become the default attributes of the output. Mutually exclusive with Output Map Projection.  | .none  |
| Output Map Projection  | [[Projection Type]]  | Projection to reproject the input map into; the output's extents and cell size are then computed automatically (either can still be overridden by the relevant ports). Mutually exclusive with Output Format Map Filename.  | .none  |
| Output Map Cell Type  | [[Cell Type Type]]  | Cell type of the output map. Unsigned 1-Bit Integer and Signed 8-Bit Integer are both treated as Unsigned 8-Bit Integer for this functor.  | Signed 32 Bit Integer  |
| Output Map Null Value  | [[Null Value Type]]  | Null value of the output map.  | .default  |
| Resampling Method  | [[Enum Type]]  | Resampling method used to compute output values from the input map: Nearest, Bilinear, Cubic, Cubic Spline, Lanzos, Average, Mode, Maximum, Minimum, Median, 1st Quartile, or 3rd Quartile. This is an advanced port.  | Nearest  |
| Additional Input Map Null Value  | [[Null Value Type]]  | Additional value to treat as null in the input map, alongside its own null value if it has one. This is an advanced port.  | .none  |
| Input Map Projection  | [[Projection Type]]  | Projection to assume for the input map, overriding its own. When not given, the input map's own projection is used. This is an advanced port.  | .none  |
| Output Map Lines  | [[Positive Integer Value Type]]  | Number of lines of the output map. Must be given together with Output Map Columns; mutually exclusive with Output Map Cell Width/Height. This is an advanced port.  | .none  |
| Output Map Columns  | [[Positive Integer Value Type]]  | Number of columns of the output map. Must be given together with Output Map Lines; mutually exclusive with Output Map Cell Width/Height. This is an advanced port.  | .none  |
| Output Map Cell Width  | [[Real Value Type]]  | Cell width of the output map, in units compatible with its projection. Must be given together with Output Map Cell Height; mutually exclusive with Output Map Lines/Columns. This is an advanced port.  | .none  |
| Output Map Cell Height  | [[Real Value Type]]  | Cell height of the output map, in units compatible with its projection. Must be given together with Output Map Cell Width/Height; mutually exclusive with Output Map Lines/Columns. This is an advanced port.  | .none  |
| Use Compression  | [[Boolean Value Type]]  | If true, the output map is compressed, for formats that support it (GeoTiff and HFA; ignored for other formats). This is an advanced port.  | Yes  |
| Additional GDAL Warp Arguments  | [[String Type]]  | Additional arguments passed to the underlying ''gdalwarp'' invocation, appended after every other argument. This is an advanced port.  | ""  |
| Additional GDAL Translate Arguments  | [[String Type]]  | Additional arguments passed to the underlying ''gdal_translate'' invocation, appended after every other argument. This is an advanced port.  | ""  |

===== Outputs =====

^ Name  ^ Type  ^ Description  ^
| Output Map Filename  | [[Map Filename Type]]  | Same filename given to the Output Map Filename input port.  |

===== Group =====

[[Functor List#GDAL / OGR | GDAL / OGR]]

===== Notes =====

This functor wraps the [[https://gdal.org/|GDAL library]] utilities [[https://gdal.org/programs/gdalwarp.html|GDAL Warp]] and [[https://gdal.org/programs/gdal_translate.html|GDAL Translate]]: GDAL Warp is used to reproject the map, and GDAL Translate is used to clip the reprojected map to the boundaries of a given mask.

Categorization information present in the input map is not preserved by the reprojection.

Only the GeoTiff (.tif) and HFA (.img) formats support Use Compression; it is ignored for other formats.

Unlike most functors, this functor cannot be connected directly to a map produced by another functor while it is still in memory — that map must first be saved to disk with [[Save Map]] — because the underlying GDAL utility can only operate on maps already written to a file. Re-arranging an in-memory map into the form GDAL's API expects would heavily impact execution performance and the amount of memory required, which is why this restriction is not worked around internally.

===== Internal Name =====

TransformMap