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Reducing Orthomosaic Resolution and Manipulating .tfw file

I spend a considerable amount of time cleaning the 1 GSD orthomosaic.  However, I often want lower resolution copies of the cleaned orthomosaic.  Changing the resolution in Step 3 loses all the edits made on the 1 GSD ortho.

I have been successful in reducing the resolution in Photoshop, but the .tfw file does not properly place and scale the ortho properly.  Is there a way to manually change the .tfw file (or metadata) for the reduced-resolution ortho so that it comes in properly.  Below is an example of the info in the .tfw file.

0.106890000000
0
0
-0.106890000000
818424.274040000048
295436.342460000014

You save the same project with different project name and process the step 3 by changing the resolution of project saved in different name. The original project processed data will not be lost…

Steps to be followed

  1. Click project (positioned in top left)

  2. select project save as

  3. assign some other name for the project.

  4. processes step 3 for the name changed project.

Regards,

Nallusamy

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Thanks, but when you do it this way, all changes made in the Mosaic Editor, are lost. 

Hi Matt,

I noticed the article Resizing Orthomosaics (.tiff) using QGIS on 3DR’s knowledge base. Have a look if it works for you.

As a side note, the newly generated file will have the geolocation information stored in the metadata and not in the .tfw file. 

Best,

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Thank you!  This method worked perfectly, and was very easy to follow.  It is helpful in my work to have different resolutions of the same georeferenced orthomosaic.  Thanks again.

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