topic Re: Generate polygons that represent historic air photo footprints? in ArcGIS Pro Questions

Generate polygons that represent historic air photo footprints?

JimLacy — Thu, 25 Sep 2025 17:40:07 GMT

I'm hoping for a conceptual push in the right direction on the following! We have many hundreds of old-school air photo indexes (pre-1950s, for example) ; these have been scanned, and we have a process in mind to georeference them with a minimal number of control points. (Labor intensive, but doable) That's not the problem though.

We ultimately need polygons in a geodatabase that represent the footprint of each photo shown on the index map. Yes, we can draw a polygon, copy/paste, move copy to right spot, attribute, repeat. Brute force, but it works.

Ideally we need a solution to help automate the creation of polygons along specified flightlines.

I thought the "generate rectangles along lines" tool looked exactly like what we need. i.e., draw the flightlines, then generate polygons. But no, the polygons created with that tool are non-overlapping. Air photos overlap considerably of course.

Is there a tool or workflow out there that could create overlapping polygons like we need? I've been googling of course, no luck so far.

Jim

Re: Generate polygons that represent historic air photo footprints?

AlfredBaldenweck — Thu, 25 Sep 2025 18:01:56 GMT

Honestly the easiest way is to mosaic them together, I bet? That creates the footprints automatically.

Re: Generate polygons that represent historic air photo footprints?

DavidPike — Thu, 25 Sep 2025 22:19:19 GMT

Just for clarity, I think that would be a Mosaic Dataset.

Re: Generate polygons that represent historic air photo footprints?

JimLacy — Thu, 25 Sep 2025 23:37:44 GMT

Thanks! But I need to explain better. We are not georeferencing the air photos… we are working on the indexes used to find analog photos. These were the maps used back in the day to locate which photo(s) you need. Our goal is to ease the editing process used to create the digital index.

example of a scanned index:

https://maps.sco.wisc.edu/apcat/Index_Scans/BURNETT/jpegs/259_05.jpg

Example of a digital index where each point represents the geographic center of a single photo:

https://uw-mad.maps.arcgis.com/home/item.html?id=15aa61bed9cd48da9116d1d45d0b481b

Re: Generate polygons that represent historic air photo footprints?

DavidPike — Fri, 26 Sep 2025 22:12:17 GMT

You might be lucky and have some pixel values which only correspond to the outlines and the index numbers, but it looks unlikely. Even so, it would only probably help with somehow turning that into the individual polygons/centroids. You'd be left with some raster cells which form a picture of the ID text, which is probably only use to a manual digitiser.

It sadly looks like some application of AI/ML or laborious digitising, but I'd be interested to see what other options people might come up with.

Re: Generate polygons that represent historic air photo footprints?

AlfredBaldenweck — Tue, 30 Sep 2025 17:32:39 GMT

Agreed. You might also get some mileage out of doing that scan like above with all the pictures together and georeferencing just that one scan to manually place the center points.

Re: Generate polygons that represent historic air photo footprints?

DEAF_PROBERT_68 — Tue, 30 Sep 2025 19:09:47 GMT

Do you have Metashape ? That will take care of your issues with the circle you marked on. I don't have it anymore because my agency revoked it due to it is from Russia.

Re: Generate polygons that represent historic air photo footprints?

JimLacy — Tue, 30 Sep 2025 19:38:26 GMT

No. I imagine that is an AI/image recognition approach of some sort?

Re: Generate polygons that represent historic air photo footprints?

DEAF_PROBERT_68 — Tue, 30 Sep 2025 19:45:43 GMT

No, it is not an AI/image .... it is a photogremmety software that is well known everywhere... Now in the USA it is Pix4D

https://www.agisoft.com/

Re: Generate polygons that represent historic air photo footprints?

DEAF_PROBERT_68 — Tue, 30 Sep 2025 19:46:59 GMT

Also, I forgot to mention this that it has structure in motion too