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Stereo Analyst Image Pairs List is empty

by Technical Evangelist on ‎10-11-2019 02:19 PM (182 Views)

Question

I have imported my photogrammetric project into SAfA but no images are displayed in the Stereo Window. And the Image Pairs list is greayed out. How can I resolve this?

Answer

Stereo Analyst for ArcGIS computes image pairs based on the Image Pair Threshold Percent option on the ArcMap Display Tab. For example, if the threshold is set to 50 percent, the two images must share at least half of the same geographic area to be considered an image pair. The overlap percentage between two photographs in a strip is commonly 60 percent. This type of image pair is ideal for stereo viewing and feature collection.

 

The default minimum overlap percentage in SAfA Options is set to 50 percent. If the overlap percentage (endlap) between strips are less than 50 percent, the image pairs will not form, and the Image Pair list will be grayed out. If you are working with images that have less than 50 percent overlap, you can change the minimum threshold value to ensure that you get image pairs you can use in Stereo Analyst for ArcGIS. To do so, go to Stereo Analyst Menu->Options->ArcMap Display Tab. And reduce the Minimum Image Pair Threshold Percent, for example reduce it to 30 percent.

 

IP.JPG

 

SAfA_Options.JPG

Comments
by
‎04-22-2020 03:05 AM - edited ‎04-22-2020 09:56 AM

Good morning,

I'm facing the same problem, but also changing the image pair threshold percent the result does not change.

Checking the images proprierties I saw that the spatial reference is undefined, so the problem could be more general. 

In Erdas Imagine where I make the block layer, the images have a right coordinate system so apparently the coordinate system does not get imported correctly in arcgis. 

P.S.: In the past the images were shown correctly, so I guess I changed some configuration..

I would really appreciate some advice about this.

Best regards 

Alessandro

Image.png

by Technical Evangelist
on ‎04-22-2020 02:56 PM

Hello,

 

In order to eliminate a data issue, could you please test with the ERDAS Extensions dataset and check if the imagepairs are listed all right? If you don't have Extensions Example data, here is the link, it will work with all versions.

 

https://download.hexagongeospatial.com/downloads/erdas-extensions-for-arcgis/erdas-extensions-2014-e...

 

Also, please review your installation order. I have seen in the past incorrect installation caused problems displaying images and re-installation resolved customers problems. For example before you upgrading any version of ArcGIS, you should first uninstall any existing installation of ERDAS Extensions. 

 

In any case please submit a support ticket for this issue through our support portal and we will help you.

 

Best Regards,

Yasemin

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