Community

How Does One Clip, Copy Or Export An Image And Preserve The Original Quality?

1971
10
03-05-2019 06:24 AM
Mark_Hotz
by
Occasional Contributor II
‎03-05-2019 06:24 AM

I have been trying to clip an image using ArcGIS Pro (2.3). I need to send this image to a 3rd party, so it's not going to be used in my system.  I am simply trying to convert an ESRI GRID format image into a smaller ESRI GRID format image.  I have tried various geoprocessing tools:

  • Extract by Mask
  • Clip (using a polygon)
  • Copy Raster (after using clip in Raster Functions)

And have used various compression settings:

  • LZ77
  • JPEG
  • LZW

I also always let the software build pyramids using the -1 option, and have tried setting "no data" to both "0" and "256".  I have not changed the projection.

None of my methods seem to work and in every case the resulting image appears coarse and no like the original at all.  All I want to be able to do is capture a piece of our high-res orthophoto and preserve the original image quality in the resulting image, which sounds fairly straight forward.

Because each iteration of my workflow takes about 15 minutes this project is starting to cost me hours...even days.  Surely there's a smart way to deal with this, right?

Original Image

Resulting Image

Suggestions?

Thank you

0 Kudos
10 Replies
Mark_Hotz
by
Occasional Contributor II
‎07-29-2020 09:20 AM

Hey Luke:

I don't process imagery that often in our organization (and we don't have ESRI's Image Server because we cannot justify it yet), so the time-lag in between our orthophoto acquisition is usually the reason I'm usually having issues processing orthophotos (i.e. I usually only process them once every 3 or so years and have to relearn it LOL).

However, we got new imagery a couple of weeks ago and I followed your suggestions above and it did work, and it worked well.  I resampled the image using the cubic convolution method (instead of allowing the default of Nearest Neighbor) and I have to think that this was the big difference.  The image output turned out perfectly.

We usually get TIFF imagery from a consultant and the only way I have been able to find to bring that into ArcGIS (and Pro) is using one of the ESRI Mosaic tool sets.  However, I also need to publish this image to our Portal for staff to review and it is my understanding that unless one has Image Server one cannot publish a Mosaic, so it has to first be exported into a single (flat) image first, and this is where I was having all of my issues.

Once a single image is created I can then easily publish that to Portal, and then cache the image (which usually takes 2 or so hours), and from there it usually works perfectly for staff.

So thanks again for your advice...it is very appreciated most useful, and a major time-saver.

0 Kudos