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9
votes
5answers
368 views

Raster diff: how to check if images have identical values?

Is there a means to check to see if any 2 given raster layers have identical content? We have a problem on our corporate shared storage volume: it's now so big that it takes over 3 days to conduct a ...
1
vote
1answer
18 views

Compressing multiple static layers to single layer to make web map loading faster?

In our web application there are many layers to be loaded, this cause the loading of map very slow. I am seeking a way to compress multiple static layers to a single layer to make the loading ...
2
votes
1answer
138 views

What methods exist for geohash of polygon?

GeoHash is an excellent method to code the latitude and longitude of a point into a string. It's concise, due to the use of numbers + letters, and the precision can be tuned adding characters at the ...
0
votes
0answers
71 views

ERDAS Imagine ecw compression settings

We have some jp2 or img satellite images that we compress to .ecw using ERDAS Imagine. We have realized that with some images we are losing too much information while doing that. What i wanted to ask ...
0
votes
0answers
54 views

Raster format similar to ECW

I need an alternative to the ECW format that we currently have for a new series of Ordnance Survey maps. The ECW format looks clearer and less pixelated than the new maps in Tif format (in QGIS). ...
2
votes
0answers
311 views

Why does compressed & zipped/unzipped file geodatabase give Open Failed Error opening feature class Cannot access secured data?

In Arc 10.2, a colleague compressed a file geodatabase and then zipped it and sent it to my via email. I unzipped it and was unable to add any of the feature classes into my map document. I received ...
1
vote
1answer
217 views

When trying to convert an .e00 file into a shapefile with ogr2ogr, getting “ERROR 4: This looks like a compressed E00 file”

When I ran this command: ogr2ogr topo.shp flowe86hyp.e00 I got this error: ERROR 4: This looks like a compressed E00 file and cannot be processed directly. You may need to uncompress it first ...
2
votes
1answer
62 views

What does the predictor switch do while compressing geoTIFFs in GDAL

I am merging several geoTIFFs into one and am using the -co COMPRESS=DEFLATE create option for geoTIFFs. An additional switch is the predictor switch. What does it do? The GDAL website is not clear ...
1
vote
2answers
755 views

How to compress raster image for publishing?

I have a (8-bit) satellite image that is e 6 gb. Is there a way I can compress the image smaller size without losing the quality? Format: .tif Reason: After publish the image, I notice a higher usage ...
6
votes
2answers
565 views

How can I reduce the size of my file geodatadase?

We're using file geodatabase for tax mapping. we save building photos and there are 6000 buildings. The size of this data 2GB. So loading the data takes a lot of time we are not unable to do work ...
6
votes
2answers
269 views

Wavelet vs Discrete compression for imagery

What is the main reasons to choose wavelet (jp2, sid, ecw) instead of discrete (JPEG) compression methods for raster data? Lets limit this question to aerial imagery and lossy compression. Why ...
4
votes
1answer
587 views

Using PNG/JPEG Compression in GeoServer

Is there any use in setting the PNG and JPEG compression in GeoServer (Services - WMS - PNG Options/JPEG Options)? The default is 25, but we heard rumours that having compression resulted in a time ...
2
votes
0answers
84 views

Classify trajectory compression algorithm

I'm tryng to classify each compression algorithm based upon their features, i've thinked: Compression algorithm Lossless algorithm Batched algorithm Rinex Lossy algorithm Batched algorithm ...
1
vote
2answers
447 views

Open MapGuide MrSID rasters with FDO GDAL. invalid extent. Not drawing

When I try and save the resource I get: Spatial context extent appears to be invalid (or Default). The XML: <?xml version="1.0"?> OSGeo.Gdal.3.4 Default This coordinate system ...
0
votes
1answer
371 views

Create moving map application from topographic maps

I'm trying to create a moving map application for an embedded ATOM device. Data source is a 400MB tif file (500dpi) plus projection and worldfile. My naive approach was to load that tiff into Global ...
18
votes
6answers
6k views

Should GDAL be set to produce GeoTIFF files with compression? Which algorithm should be used?

I have a folder of GIS data that consists mainly of GeoTIFF files. The whole set weighs in at about 1.2 GB. I noticed that if I pack the contents into a tarball, it smashes down to about 82 MB. I ...