Agisoft Metashape

Agisoft Metashape => General => Topic started by: macki on January 09, 2015, 09:43:18 PM

Title: Measuring in a model that was built using geotagged images?
Post by: macki on January 09, 2015, 09:43:18 PM

Hello,

First time using Agisoft! I built a model using images and a corresponding XYZ coordinates I prepared as a csv file. The model built, and now I'd like to make some measurements on the model.

Reading the documentation, it seems that, even though the images are georeferenced, I still need to calibrate/scale the model using some markers. The most exact measurements I have are the distances between the georeferenced photos. Is it possible to use these distances between photos to scale the model, or do I have to provide a measurement for something in the pictures? I don't have any exact coordinates of objects seen in the photos, but I gather addtional distance information between points seen in the photos.

Thanks for any tips

Title: Re: Measuring in a model that was built using geotagged images?
Post by: stihl on January 10, 2015, 03:46:05 PM

Is it an aerial photogrammetry project or closed range photogrammetry?

If it's the first, you'll need ground control points (GCP's) to reference the relative model to giving it an absolute position. The aerial GPS is insufficient to scale or reference the model accurately. You'll need measured in GPS points on the project location that you can find in the photo's.

Title: Re: Measuring in a model that was built using geotagged images?
Post by: macki on January 12, 2015, 08:15:35 PM

Hello stihl,

It is close-range photogrammetry... how does the GCP need change in this instance?