arcgis-desktopclipextract-by-maskgeotiff-tiffraster
If I import a tiff file of a zoning map for a city and then georeference it to a shapefile of the city boundary, is it possible to clip the georeferenced tiff file to the city boundary shapefile?
I have tried to use the extract by mask tool to do this, but even after making sure the tiff and shapefiles were in exactly the same projection, the tool would not work.
It is not possible for autocad (base) to understand georeferencing information in the tiff.
If a colleague were to load the image for you with a projection and the georeferenced image into a drawing (using autocad map 3d), that drawing can be opened and used in autocad.
I ran a test to determine how the speed and quality differs between the two methods, here are the results:
Input data
Performance
Three trials were performed and benchmarked. The Clip (Data Management) method is significantly faster than the Extract by Mask (Spatial Analyst) method.
Quality
Both extents were identical as were NoData values. However, a visual assessment showed that the extract by mask method slightly altered the pixel arrangement--likely the result of some type of resampling. The pixel arrangement in the clip operation were identical to the original input image.
# Import system modules
import arcpy, time, os
from arcpy import env
from arcpy.sa import *
env.overwriteOutput = 1
# Check out the ArcGIS Spatial Analyst extension license
arcpy.CheckOutExtension("Spatial")
# Set local variables
inRaster = r'C:\temp\naip2011.img'
inMaskData = r'C:\temp\fgdb.gdb\clipper'
outws = r'C:\temp'
out1 = os.path.join(outws, 'extractbymask.img')
out2 = os.path.join(outws, 'clip.img')
#############TRIAL 1: EXTRACT BY MASK#########################################
start = time.clock()
# ExtractByMask
outExtractByMask = ExtractByMask(inRaster, inMaskData)
# Save the output
outExtractByMask.save(out1)
end = time.clock()
total = end - start
print "The extract by mask method took: %s seconds" % round(total, 3)
###############TRIAL 2: CLIP#################################################
start = time.clock()
# Clip
arcpy.Clip_management(inRaster, "#", out2, inMaskData, "", "ClippingGeometry")
end = time.clock()
total = end - start
print "The clip method took: %s seconds" % round(total, 3)
Best Answer
There are two ways to do it:
Use raster clip tool (as "output extent" use your city boundary shape) http://help.arcgis.com/EN/arcgisdesktop/10.0/help/index.html#//00170000009n000000