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I have hundreds of georeferenced jpgs in ArcGIS 10 that I need to convert to geotiffs.

I'm trying to use GDAL translate to create geotiffs from them. Everything works great except that the resultant geotiff is slightly shifted/warped (see image 1 and note that the road locations are shifted on the right panel.) Can anyone suggest how to convert georeferenced jpgs to geotiffs without this shift/warp?

My GDAL command to create this geotiff was:

gdal_translate -of GTiff input_file.jpg output file.tif

Gdaltranslate indicates exactly the same coordinate system and bounding coordinates between the jpg and the geotiff (image 2). I'm not sure what is wrong.

Thank you for your help! (Images are provided as dropbox links because I don't have enough reputation points to post images here.)

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The gcs name has changed in the GeoTIFF. It's possible that ArcGIS is treating it as not-equal to other data in NAD83. When overlaying the vector data, should a transformation occur (say to NAD27)? If so, the transformation may not be applied, thus the offset. –  mkennedy Feb 25 '13 at 22:33
    
It might help if you can post a sample of the source data. –  BradHards Feb 26 '13 at 3:21
    
Thanks for the suggestions! MKennedy, do you know how to specify not to change the gcs name in the geotiff? –  Stavros Feb 26 '13 at 21:36
    
The original georeferenced jpeg is here: dl.dropbox.com/u/17669584/temp/tech/040407a_001.zip. The translated geotiff is here: dl.dropbox.com/u/17669584/temp/tech/040407a_001_2.tif. I'm also concerned that the .tif image size is 300+ megs whereas the .jpg is 15 mb. –  Stavros Feb 26 '13 at 21:49
    
@Stavros The size is that big because you didn't specify any compression algorithm, so it defaults to NONE. Try with the option -co "COMPRESS=JPEG". There are many other options to choose from. Check the docs –  nickves Jun 29 '13 at 11:35
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1 Answer 1

With Google or Openstreetmap background, the original jpg is about 300metres off the correct position. Thats far more than the shift between NAD27 and NAD83.

So you have three opportunities:

1) ask the data provider how they georeferenced the photos.

2) if the shift is constantly througout all imagery, you can create a custom CRS (in Arcgis: custom datum transformation) with the same ellipsoid and play with the +towgs84 parametres until the photos align.

2) throw away everything but the .jpg file and do the georeferencing again on your own.

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