Custom Gridding on export

[STH]

Is it possible to load custom gridding from a file? We have a file that contains the grids and would like it to load in GlobalMapper and then export as GeoTiff. Perhaps add the option in "Gridding" something like "Grid Layout from Selected Area/File". Similar to "Export Bounds" and "Crop Selected Area Features(s)"? The Gridding may be described as a text-file or DXF-file? If text-file is the option then it should load the following tags:

"TileName" "NWx" "NWy" "SEx" "SEy"

Is this possible?

[global_mapper]

This is not currently possible with Global Mapper, but is something on our todo list. You could do something like this using the Global Mapper SDK, then you could just read the file yourself and do individual export commands. Or you could write a small application to create a Global Mapper script file that does all of the exports that you need, then run that script file.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[pcook911]

Mike,

Why not allow gridding based on a vector (shapefile) in the Global Mapper Workspace?

For instance right now I am using an arcscript for ArcMap to batch clip an NAIP county aerial based on the grid shapefile included in the NAIP download. It has been running for about 3 hours and it is 30% done. I guess I will leave going tonight. We all now how much faster a process like this would go if I could use Global Mapper instead.

Paul

P.S.

If there someway to accomplish this that I have missed let me know and you could be my hero.

[global_mapper]

Paul,

You can clip an export to one or more selected area features on export, but there is not currently a way to do multiple exports based on multiple selected area features (i.e. one export per area feature). This is something that we are considering for a future release though.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[STH]

I am trying to do this now. I have a done the following:

GLOBAL_MAPPER_SCRIPT VERSION="1.00" FILENAME="T:\WORKSPACE.GMW"
UNLOAD_ALL
DEFINE_PROJ PROJ_NAME="UTM_ZONE32_WGS84"
Projection     UTM
Datum          WGS84
Zunits         NO
Units          METERS
Zone           32
Xshift         0.000000
Yshift         0.000000
Parameters
END_DEFINE_PROJ
SET_BG_COLOR COLOR=RGB(100,100,100)

IMPORT FILENAME="T:\testfile.tif" \
	 TYPE="GEOTIFF" LABEL_FIELD="" ANTI_ALIAS="NO" \
AUTO_CONTRAST="NO" CONTRAST_SHARED="YES" \
	 CONTRAST_MODE="NONE" 

EXPORT_RASTER FILENAME="T:\testfile_export.tif"   \
    TYPE=GEOTIFF LAYER_BOUNDS="T:\testfile.tif"   \
    POLYGON_CROP_USE_ALL="T:\Areas.shp" \

However it does not crop at the Areas within the file Areas.shp.

I am trying to do something similar to: File - Batch convert/reproject and selecting "Crop to Selected Areas" and "Maintain Full Size When Cropped"

[global_mapper]

Your EXPORT_RASTER command should have a POLYGON_CROP_FILE="t:\Areas.shp" parameter as well as a POLYGON_CROP_USE_ALL=YES parameter. As it is not you are not actually specifying a crop file.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[STH]

I could not use this approach because of a black border around 1/2 pixel within the crop-area. So I have to do it by feathering each import file, and crop 2 pixels. So i use the following:

My final approach was to load all background files and then do this for each file on top of the background-files:

IMPORT FILENAME="newMosaic.tif" \
TYPE="GEOTIFF" PROJ_NAME="UTM_ZONE32_WGS84" LABEL_FIELD="" 
ANTI_ALIAS="NO" AUTO_CONTRAST="NO" \
CONTRAST_SHARED="YES" CONTRAST_MODE="NONE" CLIP_COLLAR="NONE" 
TEXTURE_MAP="NO" TRANSLUCENCY="512" \
FEATHER_BLEND_SIZE="2" FEATHER_BLEND_EDGES="48" 
FEATHER_BLEND_POLY="FEATHER_POLY"	
EXPORT_RASTER FILENAME="Q:\mergedMosaikk.tif" \
TYPE=GEOTIFF OVERWRITE_EXISTING="NO" LAYER_BOUNDS="newMosaikk.tif" \

However this seems to take a lot of time, and I am not sure why. Is it because of the FEATHER_BLEND_SIZE="2" - calculations? Is there a difference if you load/unload one and one file rather than loading all files in the beginning of the script? Is the problem that the files are located on a network drive and GM does not buffer the files on a temp-file locally or in memory/swap file and requires a lot of reading then the network is busy? I see that GM only use around 70-80MB of memory and the swap-file is only 3-400MB.

UPDATE: When turning off the FEATHER_BLEND completely with the same files it is lightning fast - so I guess the computation of the FEATHER_BLEND_POLY takes all the time. But I guess there is no other way to do my operation faster?

[global_mapper]

Whenever you do a polygon-based operation (i.e. crop or feather to polygon), this will tend to significantly slow down your export, particularly if the crop polygon has a lot of vertices, as the point-in-polygon operation can be slow.

However, one other thing that I notice is that you are not specifying the bounds to export when using the EXPORT_RASTER script command. When you specify a polygon crop file during export the bounds of that polygon will be used as the export bounds, but in the absence of a crop polygon or explicitly specified export bounds, the bounds of all loaded data will be used, which could be the most significant source of your slowdown as you may be exporting a lot more data that you are intending to.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

[STH]

The FEATHER_POLY I use consist of 7 different areas (non-overlapping) around 300 points within the GMW-file. They are on the format XXXXXX.XX0 , XXXXXXX.XX0. Where the last number is always zero. I guess it wont help much if I remove the 0`s at the end.

I thought that the export with: LAYER_BOUNDS="newMosaikk.tif" would use the bounding rectangle of the selected file. At least the export file seems to generate correctly and equal to the input-size. I have tried to export the Mosaic-tile as a Shape-vector-file and used that as input to LAYER-BOUNDS, and I can not see a very big difference in processing time.

[global_mapper]

Sorry, I did not see the LAYER_BOUNDS parameter. You are correct that it will specify the layer bounds to use for the export.

The format of the feather polygons does not make any difference as they are all ready into memory. The cause of your slowdown is most likely the polygons as the point-in-polygon and distance-to-polygon operations can slow things down a lot when feather blending. Other than simplifying your polygons to reduce the number of vertices there is not much that you can do.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com