Free DroneMapper 2D Ground Control Point (GCP) Tool

We have released a test / alpha version of the 2D GCP generation tool for Windows. You may experience a bug or two but overall it should be functional. Let us know if you have problems working with the 2D GCP utility or have additional feature requests. 

Essentially, you want to create a list of images that the GCP appear in and load them into the tool. The images must be geo-tagged. Once, you've loaded all the images you can navigate between the imagery to add the 2D GCP locations. The GCPs appear in a small text box on the lower left side. When you've completed all the GCP you can save this list as the 2D GCP text file. The 2D GCP file is one half of the required GCP data needed for our processing chain.

Download Link

Let us know if you have any questions. 

Instructions for use:

ZOOM IN - Control Up Arrow or Mouse Scroll Wheel
ZOOM OUT - Control Down Arrow or Mouse Scroll Wheel
ADD GCP - Hold Shift Key and Click GCP Target
PAN - Right Click on Mouse and Drag (or use scroll bars)
NEXT IMAGE - Next Button
PREV IMAGE - Previous Button
SAVE 2D GCP - Save GCP Button or File -> Save
CLEAR 2D GCP - Clear GCP Button or File -> New

We will add additional features and fixes as needed. Best regards,

Views: 1866

Comment by Chuck on April 23, 2013 at 4:41pm

JP I actually downloaded this shortly after the post from Daniel Portillo regarding their work. 

I loaded some images into the program and the only "issue" I ran into is that if I added a number of images and some had no geotagging it gave me a .NET error. I will reproduce later, do you have an issue tracker on git or bitbucket?

Also, great work, I can't wait to make use of it.

Comment by JP on April 23, 2013 at 4:44pm

Thanks! Right now the tool only works with images with geo-tags. I don't have much error checking written yet.. but if people are interested I will just release the source code for future improvements. The EXIF tags required are:

GPS Latitude

GPS LatitudeRef

GPS Longitude

GPS LongitudeRef

GPS Altitude

EXIF DateTimeOriginal

I will try and send the code up to my github page soon.

Comment by LanMark on April 23, 2013 at 8:41pm

I am confused.. what is the need this is fulfilling?   what is a 2D GCP and why would I need to be generating these?   Looks pretty cool.. just not sure on the purpose / need. 

Comment by Gary Mortimer on April 23, 2013 at 10:59pm

Well if you need to ask ;-)

Comment by Christiaan van Vollenstee on April 24, 2013 at 2:15am

Ground Control Points, which are commonly referred to as "GCPs", allow images to be georeferenced to a higher degree of accuracy. Ground control points are locations on the earth which have been accurately surveyed for both their elevation and GPS location. Without these control points an images georeferencing is based solely off of the data from positioning hardware aboard the imager and a sensor model. In addition to the increased accuracy obtained by using GCPs, a Digital Elevation Model (DEM) should be used so that you correct for elevation errors.

Comment by Rigel on April 24, 2013 at 4:51am

Hi JP, great progress as always.  One of the features you may want to include in the future is a way of calibrating camera lenses.

Comment by JP on April 24, 2013 at 5:17am

@Rigel: Good idea! 

@LanMark: More information on GCP:

Comment by Andreas on May 15, 2013 at 2:27pm

JP, a question!

Well i am kind of a newbie to the mapping and surveying world.

With this software i can input the ground control points directly from the software. Or do i still need to place some GCP´s in the field as well?

Comment by JP on May 15, 2013 at 2:34pm


Yes, you still need to have GCP targets on the ground, this tool helps you quickly generate a file with the GCP pixel locations and image names for processing. Thanks! 

Comment by Andreas on May 15, 2013 at 2:37pm

Comment by andreas.ddelnogal just nowDelete Comment

Ok, so out in the field i will:

1.- Make one visual marker to be used as GCP

2.- Input that visual marker on the software?

This visual mark (my GCP´s) is suppose to be measured with a GPS like the one from trimbles?

Excuse me for questions that might appear dumbs.


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