Parameters for display and interpretation of elevation values in terrain layers. See also Raster Parameters below for additional shared parameters.

• ELEV_FIELD - specifies the name of the attribute field to use as the elevation value for the vector features in a file
• ELEV_UNITS - specify elevation units to use for this file if it contains gridded elevation data and also for vector feature elevations that don't have a unit embedded in the elevation value. Valid values are as follows:
  • FEET - elevations in US feet
  • DECIFEET - elevations in 10ths of US feet
  • METERS - elevations in meters
  • DECIMETERS - elevations in 10ths of meters
  • CENTIMETERS - elevations in centimeters
• ELEV_OFFSET (elevation only) - specifies the offset in meters to apply to each elevation value in the layer. This allows you to vertically shift a layer to match other layers.
• ELEV_POWER (elevation only) - specifies the power value to apply to each elevation value in the layer. For example a value of 2.0 would square each elevation value before applying a scale and adding the offset. Default to 1.0 (no power).
• ELEV_SCALE (elevation only) - specifies the scale value to apply to each elevation value in the layer. This allows you to vertically scale a layer to match other layers. Default to 1.0 (no scaling).
• MIN_ELEV (elevation only) - specifies the minimum elevation (meters) to treat as valid when rendering this layer. Any elevations below this value will be treated as invalid and not be drawn or exported.
• MAX_ELEV (elevation only) - specifies the maximum elevation (meters) to treat as valid when rendering this layer. Any elevations above this value will be treated as invalid and not be drawn or exported.
• CLAMP_ELEVS (elevation only) - if a MIN_ELEV and /or MAX_ELEV value is specified, setting this to YES will make any valid elevation values outside of the specified range be clamped to the new range value rather than treated as invalid.
• VOID_ELEV (elevation only) - specifies the elevation (meters) to replace any void areas in the layer with. If not specified, the void areas will be transparent.
• SHADER_NAME (elevation only) - this sets the name of the shader to use when rendering the gridded elevation data for this layer. Use this to override use of the shared default shader just for this layer. This must be one of the names displayed in the shader drop down in Global Mapper, such as "Atlas Shader" or "Global Shader" or the name of a custom shader.
• BAND_RANGE - specifies the range of valid values found in a gridded layer. It can optionally also specify how and how to determine what values are no-data values. If not specified, these values will be automatically determined from the data. The format is a comma-delimited list of values like BAND_RANGE="min_valid,max_valid,band_validity_type,check_invalid_float,band_valid_val_1,band_valid_val_2". The _band_valid_val_1_ and _band_valid_val_2_ values are optional and depend on the _band_validity_type_ value. The individual values are:
  • min_valid - minimum valid value for grid cell samples
  • max_valid - maximum valid value for grid cell samples
  • _band_validity_type -_ specifies how to determine if a cell value is valid. The following type names are recognized:
    • ALL - all samples are valid
    • NONE - no samples are valid
    • GTE_MIN - values >= _band_valid_val_1_ are valid
    • GT_MIN - value > _band_valid_val_1_ are valid
    • NO_DATA - _band_valid_val_1_ is a specific no-data value
    • LTE_MAX - values <= _band_valid_val_1_ are valid
    • LT_MAX - values < _band_valid_val_1_ are valid
    • RANGE_OPEN - values in open range (band_valid_val_1, band_valid_val_2) are valid
    • RANGE_CLOSED - values in closed range [_band_valid_val_1, band_valid_val_2]_ are valid
  • check_invalid_float - value is 1 if data should be checked for raw float samples for infinite values. 0 if is known no values like that exist.
  • band_valid_val_1 - optional value based on _band_validity_type
  • band_valid_val_2_ - optional value based on _band_validity_type

Parameters for display of imagery. Some of the below parameters are also supported for elevation layers.

• SAMPLING_METHOD (elevation and raster only) - specifies the sampling method to use when resampling this layer.
The following values are supported
• NEAREST_NEIGHBOR - use the nearest neighbor sampling method
• BILINEAR - use bilinear interpolation
• BICUBIC - use bicubic interpolation
• BOX_2X2 - use a 2x2 box average
• BOX_3X3 - use a 3x3 box average
• BOX_4X4 - use a 4x4 box average
• BOX_5X5 - use a 5x5 box average
• BOX_6X6 - use a 6x6 box average
• BOX_7X7 - use a 7x7 box average
• BOX_8X8 - use a 8x8 box average
• BOX_9X9 - use a 9x9 box average
• MAX_2X2 - use maximum value found in 2x2 box (for image layers, use brightest color)
• MAX_3X3 - use maximum value found in 3x3 box (for image layers, use brightest color)
• MAX_4X4 - use maximum value found in 4x4 box (for image layers, use brightest color)
• MAX_5X5 - use maximum value found in 5x5 box (for image layers, use brightest color)
• MAX_6X6 - use maximum value found in 6x6 box (for image layers, use brightest color)
• MAX_7X7 - use maximum value found in 7x7 box (for image layers, use brightest color)
• MAX_8X8 - use maximum value found in 8x8 box (for image layers, use brightest color)
• MAX_9X9 - use maximum value found in 9x9 box(for image layers, use brightest color)
• MED_2X2 - use median value found in 2x2 box
• MED_3X3 - use median value found in 3x3 box
• MED_4X4 - use median value found in 4x4 box
• MED_5X5 - use median value found in 5x5 box
• MED_6X6 - use median value found in 6x6 box
• MED_7X7 - use median value found in 7x7 box
• MED_8X8 - use median value found in 8x8 box
• MED_9X9 - use median value found in 9x9 box
• MIN_2X2 - use minimum value found in 2x2 box (for image layers, use darkest color)
• MIN_3X3 - use minimum value found in 3x3 box (for image layers, use darkest color)
• MIN_4X4 - use minimum value found in 4x4 box (for image layers, use darkest color)
• MIN_5X5 - use minimum value found in 5x5 box (for image layers, use darkest color)
• MIN_6X6 - use minimum value found in 6x6 box (for image layers, use darkest color)
• MIN_7X7 - use minimum value found in 7x7 box (for image layers, use darkest color)
• MIN_8X8 - use minimum value found in 8x8 box (for image layers, use darkest color)
• MIN_9X9 - use minimum value found in 9x9 box (for image layers, use darkest color)
• BLUR_3X3 - perform a Gaussian Blur using 3x3 kernel
• BLUR_5X5 - perform a Gaussian Blur using 5x5 kernel
• BLUR_7X7 - perform a Gaussian Blur using 7x7 kernel
• ANTI_ALIAS [DEPRECATED - use SAMPLING_METHOD instead] (elevation and raster only) - specifies whether to remove jagged edges by making a subtle transition between pixels. Turning off this option helps maintain the hard edges of the pixels as they are rasterized. Use ANTI_ALIAS=YES to turn on. Anything else turns it off.
• TRANSLUCENCY (elevation and raster only) - specifies the level of translucency (i.e. how "see-through" the layer is). Value values range from 0 to 512, with 0 meaning the layer is completely transparent (i.e. invisible) and 512 meaning the layer is completely opaque (this is the default).
• IGNORE_ALPHA (raster only) - specifies that an embedded alpha channel in an image should be ignored. This is useful for images that have incorrect alpha channels. Use IGNORE_ALPHA=YES to enable.
• BLEND_MODE (elevation and raster only)- specify blend mode to use for combining this overlay and any previously loaded overlays
  • NO_BLEND - no blending is done, this is the default
  • MULTIPLY
  • SCREEN
  • OVERLAY
  • HARD_LIGHT
  • COLOR_BURN
  • COLOR_DODGE
  • DARKEN
  • LIGHTEN
  • DIFFERENCE
  • EXCLUSION
  • APPLY_COLOR
  • APPLY_COLOR_REVERSE
  • KEEP_RED
  • KEEP_GREEN
  • KEEP_BLUE
  • SPOT_NATURAL_COLOR_SPOT_TO_NATURAL
  • PSEUDO_NATURAL_COLOR_CIR_TO_NATURAL
  • COLOR_TO_GRAYSCALE
• FEATHER_BLEND_EDGES (raster only) - specifies that the layer should be feature-blended around one or more ledges. This is a numeric bitfield value. Add (sum) the following values to enable blending on that edge:
  • 1 - blend top edge
  • 2 - blend bottom edge
  • 4 - blend left edge
  • 8 - blend right edge
  • 32 - just crop to feather boundary rather than feathering
  • 64 - feather outside polygon edge

  For example, to blend all edges, use FEATHER_BLEND_EDGES=15. The FEATHER_BLEND_SIZE parameter is used to specify how many pixels to blend on each blended edge.

• FEATHER_BLEND_SIZE (raster only) - specifies the size in pixels to use for a blend boundary.
• FEATHER_BLEND_POLY (raster only) - specifies the name of a previously defined shape from The DEFINE_SHAPE command allows a multi-point shape (like a polygon) to be associated with a name. The shape name can then be used in later commands for things like cropping and feathering to polygonal boundaries. to feather too. You can also use FEATHER_BLEND_POLY=COVERAGE to calculate the polygonal coverage of the layer and feather blend to that automatically. To feather multiple shapes, also include the POLYGON_CROP_USE_EACH=YES parameter.
• FEATHER_BLEND_POLY_FILE (raster only) - specifies that the polygon boundary to feather blend this layer against should come from the specified file. To feather multiple shapes, also include the POLYGON_CROP_USE_EACH=YES parameter.
• BAND_SETUP (raster only) - specifies what bands of data from the raster file being loaded should be used to populate the red, green, and blue color channels when displaying the image. This is useful for multi-spectral imagery which may have more than 3 color bands. The default band setup will be to use the first three bands as follows: BAND_SETUP="0,1,2". Note that not all raster formats support specifying a non-default band setup.
• CONTRAST_MODE (raster only) - specifies the type of contrast adjustment to apply to the data.
  • NONE - no contrast adjustment applied (this is the default)
  • PERCENTAGE - apply a percentage contrast adjustment. The CONTRAST_STRETCH_SIZE parameter can be used to override the number of standard deviations from the mean to stretch to.
  • MIN_MAX - apply a min/max contrast stretch, stretching the available range of values in each color band to the full range of 0-255. For imagery which contains both black and white, this will have no affect.
• CONTRAST_SHARED (raster only) - specifies whether or not the contrast adjustment for this layer will share the adjustment with other contrast-adjusted layers in order to ensure a consistent modification across layers. Use CONTRAST_SHARED=YES to enable contrast sharing.
• CONTRAST_STRETCH_SIZE (raster only) - specifies the number of standard deviations from the mean to use in a PERCENTAGE contrast adjustment. The default is 2.0.
• AUTO_CONTRAST (raster only) - DEPRECATED, use CONTRAST_MODE instead - specifies whether to automatically calculate and apply a 2 standard deviation contrast adjustment to the image. Use AUTO_CONTRAST=YES to turn on. Anything else turns it off.
• COLOR_INTENSITY(DEPRECATED use COLOR_INTENSITY_FULL parameter) (elevation and raster only). - specifies the color intensity to use when adjusting the brightness of pixels in the overlay. Valid values range from 0 to 20, with 0 being completely black, 10 being no alteration, and 20 being completely white. For example, to make an image slightly darker, you could use COLOR_INTENSITY=7.
• COLOR_INTENSITY_FULL (elevation and raster only) - specifies the color intensity to use when adjusting the brightness of pixels in the overlay. Valid values range from 0 to 512, with 0 being completely white, 256 being no alteration, and 512 being completely black. For example, to make an image slightly darker, you could use COLOR_INTENSITY=300. (NOTE: This parameter replaces the COLOR_INTENSITY parameter).
• TEXTURE_MAP (raster only) - specifies that this image should be draped over any elevation data loaded before it. Use TEXTURE_MAP=YES to turn on. Anything else turns it off.
• PALETTE_NAME (palette-based raster only) - specifies the filename of a recognized palette file to override the default colors in this layers palette or a palette previously defined with the DEFINE_PALETTE command. Use this to change the color interpretation of palette indices.
• TRANSPARENT_COLOR (elevation and raster only) - specifies the color to make transparent when rendering this overlay. The color should be specified as RGB(<red>,<green>,<blue>). For example, to make white the transparent color, use TRANSPARENT_COLOR=RGB(255,255,255). If you do not wish any color to be transparent, do not use this parameter. Optionally, if the image that you are making transparent uses a palette for the colors, you can specify a palette index in the following format: INDEX(<0-based palette index>). For example, to make the second color in the palette transparent, use TRANSPARENT_COLOR=INDEX(1).
• TRANSPARENT_COLOR_DIST - for layers that have specified a color to make transparent, this parameter allows you to specify how far a color in the layer has to be from the specified TRANSPARENT_COLOR value to be treated as transparent as well. The default value of 0 means that the colors have to exactly match for the pixel to be treated as transparent. Larger values (up to 256) allow larger distances between the layer color and the transparent color. This is useful for lossy formats, like JPEG.
• COLOR_GRADE (raster only) - specifies the color grading values to use for this layer (as configured on the Color Grade options dialog tab). This should be a comma-delimited list with the saturation value (from 0-1) first, then the input and output range for the red, green, and blue color channels, as follows: COLOR_GRADE=saturation,red_in_start,red_in_end,red_out_start,red_out_end,...,blue_out_end
• CLIP_COLLAR (raster only) - specifies whether to clip the collar off of the image. The following values are supported for cropping:
  • NONE - no collar cropping is performed.
  • AUTO - automatically remove a USGS DRG-style collar or a 3.75 DOQQ collar
  • LAT_LON - crop the collar to a a specified set of bounds specified in arc degrees in the native datum of the layer. The bounds should be specified using the CLIP_COLLAR_BOUNDS parameter.
  • NATIVE - crop the collar to a specified set of bounds specified in the native projection system and datum of the layer. The bounds should be specified using the CLIP_COLLAR_BOUNDS parameter.
  • PIXELS - crop a given number of pixels off of each side of the layer. The number of pixels to remove from each side should be specified using the CLIP_COLLAR_BOUNDS parameter.
  • SNAP_DEGREES - crop the collar by snapping each edge to a specified degree boundary specified in arc degrees in the native datum of the layer. The bounds should be specified using the CLIP_COLLAR_BOUNDS parameter. For example to crop the west and east edges to a half degree boundary and the north and south edges to a one degree boundary, use the following: CLIP_COLLAR_BOUNDS=0.5,1.0,0.5,1.0.
  • POLY - crop to a polygon provided with the CLIP_COLLAR_POLY parameter.
• CLIP_COLLAR_BOUNDS (raster only) - specifies the bounds of the collar to be clipped off when the CLIP_COLLAR parameter is enabled. The coordinates should be specified in arc degrees, native layer coordinates, or pixel counts as a comma-delimited list going west,south,east,north. For example, CLIP_COLLAR_BOUNDS=34.25,-109.0,34.375,-108.875.
• CLIP_COLLAR_POLY (raster only) - specifies the name of the previously defined shape (with the DEFINE_SHAPE command) to crop the layer to when the CLIP_COLLAR=POLY parameter is used. The coordinates in the shape must have been defined in the native projection system of the layer being loaded. Unless you provide CLIP_COLLAR_POLY_SIMPLIFY=NO, the clip polygon will be simplified to 1/10th of a pixel resolution to reduce the size of the crop polygon for faster cropping without noticeably changing the shape.
• CLIP_COLLAR_POLY_EXCLUDE (raster only) - specifies that the crop to the polygon specified with CLIP_COLLAR_POLY should keep all parts of the layer outside the crop polygon(s) rather than what is inside the polygon(s). Add CLIP_COLLAR_POLY_EXCLUDE=YES to enable this behavior.
• CLIP_COLLAR_POLY_SIMPLIFY - specifies that the clip polygon will be simplified to 1/10th of a pixel resolution to reduce the size of the crop polygon for faster cropping without noticeably changing the shape. Enabled by default, use CLIP_COLLAR_POLY_SIMPLIFY=NO to disable.
• CLIP_COLLAR_POLY_PIXEL (raster only) - specifies that the coordinates in the crop polygon from the CLIP_COLLAR_POLY parameter are in pixel relative coordinates for the layer rather than in the native system of the layer. Use this if you need to crop a layer to a particular boundary in known pixel coordinates. The coordinates will convert to native layer coordinates on load.

• VIDEO_FILENAME - specifies the full path and filename or URL for a video file to associate with the layer. This video can then be displayed for selected point or line features with a video timestamp.
• LAYER_FLAGS - specifies various options for the layer (like mesh/3D model display options). This is a bit-mask field that can be specified as an integer or hex number (i.e. 0x3). To build the value, simply add each of the numeric options for the flags you want and then store that number (or convert to hex notation - 0xXXX):
  • 1 - Mesh Display - Wireframe Only - If 1 is added to the value, display textured or colored mesh (3D model) features only using a wireframe (i.e. do not fill them).
  • 2 - Mesh Display - No Wireframe on Zoom - If 2 is added to the value, textured/filled mesh (3D model) features will NOT display a wireframe over the color display when zoomed in far enough that the triangles are large.
  • 4 - Mesh Display - Don't Interpolate Textures - If 4 is added to the value, nearest neighbor rather than bilinear interpolation will be used when sampling the texture for a mesh (3D model). This is slightly faster, but will result in pixelated display when zoomed in.
• USE_LEGACY_IMPORTER - For TYPE=DXF files only. If USE_LEGACY_IMPORTER=YES is specified the DXF file will be loaded using the legacy import method.

The parameters below allow specifying how to create display labels for vector layers.

• LABEL_FIELD - specifies the name of the attribute field to use as the label attribute for the features in the file. By default the attribute-based labeling will only be applied to those features that don't already have a label, but if the LABEL_FIELD_FORCE_OVERWRITE attribute is set to YES then all features will have their labels replaced. If you want to build the label from multiple attributes, separate them with '>+<' in the file, like LABEL_FIELD='RD_PREFIX>+<RD_NAME>+<RD_SUFFIX'.
• LABEL_FIELD_SEP - specifies the attribute separator to use when building a label from multiple attributes. This can be any character(s). For example LABEL_FIELD_SEP='-' will insert a dash between each attribute. Use hex codes to add any non-printable characters, such as LABEL_FIELD_SEP='0x20' to add a space.
• LABEL_CUSTOM_DEF - specifies a custom free-form string describing how to form the display labels for this layer. This can include embedded attribute values as %ATTR_NAME%.
• LABEL_FIELD_FORCE_OVERWRITE - specifies that the LABEL_FIELD or LABEL_CUSTOM_DEF attribute value should be applied to all feature labels, not just those that don't already have labels. Use LABEL_FIELD_FORCE_OVERWRITE=YES to enable.
• SHOW_LABELS - specifies whether or not labels are shown for features in this layer, assuming they would be otherwise shown. The default is SHOW_LABELS=YES. Use SHOW_LABELS=NO to disable the display of labels for this layer regardless of other settings.
• LABEL_PREFIX - specifies the prefix to prepend to attribute-based labels
• LABEL_SUFFIX - specifies the suffix to append to attribute-based labels
• LABEL_FORMAT_NUMBERS - specifies whether or not numeric attribute values should automatically have formatting applied to them. This is enabled by default. Use LABEL_FORMAT_NUMBERS=NO to disable numeric formatting and keep numeric values exactly as they are in the attribute list.
• LABEL_PRECISION - value is an integer indicating the number of decimal digits to use. This applies to numeric labels.
• LABEL_REMOVE_TRAILING_ZEROS - This removes the trailing zeros to the right of the decimal place in numeric labels. This can be specified by listing the parameter alone, or accepts boolean values.
• LABEL_USE_SCIENTIFIC_NOTATION - Display the number in scientific notation. This accepts boolean values, or can be called by listing the parameter alone.

The parameters below allow specifying options for working with Lidar data.

• LIDAR_DRAW_MODE - specifies how points in a Lidar point cloud layer should be drawn. The following values are supported:
  • COLOR - if the points have an associated RGB color, use that. Otherwise color by elevation.
  • ELEV - color by elevation of the point using the current elevation shader.
  • INTENSITY - color as a grayscale image by the intensity
    • LIDAR_INTEN_SHADER - Specify the terrain shader to be used to color intensity value when using the INTENSITY draw mode option. If this parameter is provided with an empty value the terrain shader selected on the main toolbar will be used.
  • CLASS - color by the point classification
  • RETURN - color by the return number
  • HEIGHT_ABOVE_GROUND - color by the height above ground
  • POINT_SOURCE_ID - color by the point source ID
  • BY_LAYER - color the point cloud based on the source layer
    • COLOR - Use this parameter to specify a custom color, format RGB(R,G,B), to use when using the BY_LAYER draw mode option. If not specified, automatic color assignment will be used when coloring by source layer.
  • POINT_INDEX - color by the index of the point in the cloud
  • RETURN_HEIGHT_DELTA - color by the difference in height between first and last return
  • CIR - color as color infrared if NIR band present
  • NDVI - color by calculated NDVI value if NIR band present
  • NDWI - color by calculated NDWI value if NIR band present
  • DENSITY - color by point density
  • WITHHELD - color by withheld flag
  • OVERLAP - color by overlap flag
  • KEY_POINT - color by key point flag
  • SORT_LIDAR - specifies if a Lidar point cloud format should spatially sort the data on load for better performance. This will override any sort settings from the LOAD_FLAGS parameter. The following values are supported
    • AUTO - spatially sorts the point cloud data only if it is determined to be poorly sorted
    • YES - always spatially sort the point cloud data.
    • COLOR - do not spatially sort the point cloud data
• LIDAR_POINT_SIZE - specifies how large the points in a Lidar point cloud are drawn. The default value of 0 will automatically scale the points to be larger as you zoom in on them. Specify a fixed number to always draw them at a particular size in pixels.
• LIDAR_DRAW_QUALITY - specifies the quality setting (0-100) for drawing the Lidar point cloud. Larger values draw a larger fraction of the points when zoomed out, but the draw will take longer to complete.
• LIDAR_FILTER - specifies a comma-separated list of Lidar class numbers to enable or disable for load. Provide a minus sign (-) to remove the type from the filter rather than add it. The filter starts off with nothing in it if you provide a LIDAR_FILTER string, but you can add ALL to enable everything or NONE to clear the filter, then add or remove stuff after that. For example, to specify a class filter with only types 2 and 3 enabled, use LIDAR_FILTER="NONE,2,3". To get one with everything but classes 2 and 3, use LIDAR_FILTER="ALL,-2,-3".
• LIDAR_RETURN_FILTER - specifies a comma-separated list of Lidar return types to enable or disable for load. Provide a minus sign (-) to remove the type from the filter rather than add it. The filter starts off with loading everything, but you can add ALL to enable everything or NONE to clear the filter, then add or remove stuff after that. For example, to specify a return filter with only unknown and first returns, use LIDAR_RETURN_FILTER="NONE,0,1". To get one with everything but the first return, use LIDAR_RETURN_FILTER="ALL,-1". The numeric values have the following meanings:
  • 0 - Unknown Returns
  • 1 - First Return
  • 2 - Second Return
  • 3 - Last Return
  • 4 - Single Return
  • 5 - First of Many Returns
  • 6 - Second of Many Returns
  • 7 - Third of Many Returns
  • 8 - Last of Many Returns
• LIDAR_USE_INTEN_FOR_NIR - specifies that we should treat the intensity value Lidar points as the NIR (near infrared) value if the point cloud has RGB colors but no NIR values of its own. Use LIDAR_USE_INTEN_FOR_NIR=YES to enable.

• LIDAR_INTEN_RANGE - specifies the valid range of intensity values to expect when loading a Lidar point cloud. Provided as LIDAR_INTEN_RANGE="min,max", like LIDAR_INTEN_RANGE="0.0,1.0" if intensities are in range 0-1. If provided, the raw intensity value from the file will be scaled from the specified range to the standard Lidar intensity range of [0,65535].

The parameters below allow defining a series of control points and rectification parameters for setting up a coordinate mapping from pixel space to real-world projection coordinates for the layer.

• HAS_3D_POINTS - If HAS_3D_POINTS=YES is used, then the control points will have a Z component after each XY value. If 3D control points are provided, they will shift Lidar, 3D vectors or 3D model layers using the best-fit 3D transform.
• GCP - specifies a single ground control point for use in rectifying a file. The GCP record consists of 5 comma-delimited fields, the control point name, the pixel X and Y coordinates, and the corresponding ground X and Y coordinates. A separate GCP parameter and value should be used for each control point used in the rectification. As an alternative, the GCP_FILENAME parameter (see below) can be used instead.
  When HAS_3D_POINTS is used the expected values are like GCP="name,x_from,y_from,z_from,x_to,y_to,z_to"
• GCP_FILENAME - specifies the name of a control point file used to rectify the file being imported. the expected format in the file when HAS_3D_POINTS is provided is: x_from,y_from,z_from,x_to,y_to,z_to,name. Note the name is optional.
• GCP_PROJ_NAME - specifies the name of the projection that the ground control points are provided in. This name must have been defined with a prior DEFINE_PROJ command. Use this if you want to specify control points in a projection other than what you want to define as the native projection for the file. Note that you must also explicitly specify the name projection of the file using either the PROJ, PROJ_NAME, PROJ_EPSG_CODE or PROJ_FILENAME parameters.
• TRANSFORM_FILENAME - specifies the name of a control point file used to transform the coordinates of the imported file. This is different than the GCP_FILENAME in that the file defines a mapping of world coordinates to a new set of world coordinates rather than pixel coordinates to world coordinates. Each line should be of the format: x_orig,y_orig,x_new_y_new
• GCP_PROJ_FILENAME - specifies the name of the projection (.prj) file that contains the projection definition for the projection that the ground control points are provided in. Use this if you want to specify control points in a projection other than what you want to define as the native projection for the file. Note that you must also explicitly specify the name projection of the file using either the PROJ, PROJ_NAME, PROJ_EPSG_CODE or PROJ_FILENAME parameters.
• GCP_PROJ_EPSG_CODE - specifies the EPSG code of the projection that the ground control points are provided in. Use this if you want to specify control points in a projection other than what you want to define as the native projection for the file. Note that you must also explicitly specify the name projection of the file using either the PROJ, PROJ_NAME, PROJ_EPSG_CODE or PROJ_FILENAME parameters.
• RECTIFY - specifies the rectification method to use for rectifying this file. Valid value are LINEAR, HELMERT, AFFINE, POLYNOMIAL, and TRIANGULATION. If you do not specify a rectification type but do provide at least two ground control points, the best rectification method will automatically be chosen based on the number of control points specified.
• RECTIFY_4_POINT_POLY_ONLY - specifies that if RECTIFY=POLYNOMIAL is used to specify the rectification method, the polynomial will always be a 1st degree polynomial and won't switch automatically to a 2nd degree polynomial at 6 or more points. By default, the 2nd degree polynomial will automatically be used