[GIS] Using Mosaic to New Raster in ModelBuilder

arcgis-10.2arcgis-desktoperror-000732modelbuildermosaic

I have a large number of airphotos giving coverage of an area going back decades. – someone may have a smoother means to accomplish my goal here. I'm weak in Python sadly. I'm attempting to shrink/trim/eliminate a given number of pixels along the edges of the .TIF airphotos that I have.

The photos are quite old and scanned from negatives, and have black borders from the scanning of the film negatives, so I can't set nodata=0,0,0 as the border isn't a perfect 0,0,0 (in some cases water features are closer to 0,0,0 that then border is)

There's too many images to sensibly do this individually. I'll walk through my thoughts/plan below. My end goal is to use Build Footprints 'Shrink Distance' Feature:

Use recursive iteration to go through every .geotiff airphoto within the "airphotos" folder.
Create a file geodatabase where the name of the .gdb matches the raster
Create a Mosaic Dataset within that File Geodatabase [Mosaicmb]. The tools run as hoped up to this point, i've been able to create all the geodatabases.
Here the problems start: Add the raster that is being iterated to the newly created empty mosaic dataset. Fails with the error listed below
Build Footprints, and use the shrink feature to eliminate my borders, by cutting say 50 pixels off all sides of each photo.

ArcGIS reports that mosaicmb doesn't exist – which it obviously doesn't, and it won't exist until the tool runs.

If you know a slick way to trim border pixels, that will help too.

Error 000732 - Mosaic Dataset: Dataset Q:\.......\test5\%name%.gdb\mosaicmb does not exist or is not supported

I'm still experimenting and trying what works, but at this point I'm shooting in the dark and praying. I'll update if I have a breakthrough.

Best Answer

You might attempt to set a "precondition" by linking the mosaicmb variable to the Add Raster To Mosaic Dataset a second time, and choosing "precondition" when the connect tool of ModelBuilder shows it's context menu.

A pre-condition will ensure the File Geodatabase and Mosaic Dataset will be created in advance of the Add Raster To Mosaic Dataset being run.

See the ArcGIS Help: http://desktop.arcgis.com/en/desktop/latest/analyze/modelbuilder/a-quick-tour-of-using-precondition.htm

Related Solutions

[GIS] Converting multiple rasters to new raster (mosaic) in ModelBuilder

You need two models, a main model and a sub model. The main model iterates through your folders, calls the sub model - which collects all the rasters within the current folder and passes the results back to the main model and into the mosaic to new raster tool.

Main Model - selects a folder and passes it to the sub model. Mosaics rasters from sub model.

enter image description here

Sub Model - collects rasters within folder and pass them back up.

[GIS] Clipping Rasters from Mosaic Dataset in Original Coordinate System

Set the Output Coordinate System environment setting when clipping the raster using Extract by Mask with an input shape file. If you are implementing this in python you should be able to grab the coordinate system from the shape file using the describe method.

Projecting/converting WGS84 World Mercator to WGS84 UTM zone 14N does not require a parameter transformation as they are based on the same geographic coordinate system, if they were dissimilar then this would not work.

Here is a script that will clip a raster mosaic to a shapefile and match the output coordinate system to the shapefile:

import arcpy, sys

InRasterMosaic = sys.argv[1]
InShapeFile = sys.argv[2]
OutRaster = sys.argv[3]

if arcpy.CheckExtension("Spatial") == "Available":
    arcpy.AddMessage("Checking out Spatial")
    arcpy.CheckOutExtension("Spatial")
else:
    arcpy.AddMessage("Unable to get spatial analyst extension")
    sys.exit(0)


desc = arcpy.Describe(InShapeFile)
SR = desc.spatialReference
arcpy.env.outputCoordinateSystem = SR

ExRas = arcpy.sa.ExtractByMask(InRasterMosaic,InShapeFile)
ExRas.save(OutRaster)
arcpy.CheckInExtension("Spatial")

I have tested this and it works! Have a read of Adding a Script Tool, follow those instructions and you can put this into a model.

If the input is in WGS (DD) as stated:

import arcpy, sys, os

InRasterMosaic = sys.argv[1]
InShapeFile = sys.argv[2]
OutRaster = sys.argv[3]

if arcpy.CheckExtension("Spatial") == "Available":
    arcpy.AddMessage("Checking out Spatial")
    arcpy.CheckOutExtension("Spatial")
else:
    arcpy.AddMessage("Unable to get spatial analyst extension")
    sys.exit(0)

# from the geographic extent, get the centre
# of the extent, only the X is required
desc = arcpy.Describe(InShapeFile)
Ext = desc.Extent
CentX = ( Ext.XMin + Ext.XMax ) / 2

# I'm not familiar with North American projections
# so you'll have to put the numbers in for each zone
if CentX < Zone14max:
    ProjSR = arcpy.SpatialReference(32614)
elif CentX < Zone15max:
    ProjSR = arcpy.SpatialReference(32615)
# continue for the required spatial references
else:
    arcpy.AddMessage("Unable to establish coordinate system")
    arcpy.CheckInExtension("Spatial")
    sys.exit(-1)

arcpy.env.outputCoordinateSystem = ProjSR

ExRas = arcpy.sa.ExtractByMask(InRasterMosaic,InShapeFile)
ExRas.save(OutRaster)

arcpy.CheckInExtension("Spatial")

This will need you to make some edits, but will basically do what you're after. Using the centroid of the extent work out which zone it's likely to be in and then use that for the output coordinate system. The numbers are the SRID of the output coordinate system like this one http://spatialreference.org/ref/epsg/32614/

Related Question

[GIS] Mosaic To New Raster – Raster Cells Shift