No IPs found on orthophoto using ipfind

[Aleksandra Podbielska]

Hi all,

my overall goal is to use ipfind and ipmatch on two HiRISE orthophotos to derive transformation parameters. I got stuck on the first step, as for one of them I get around 20-60k "detected raw keypoints" and zero "found points". For the other one with ~35 000 raw keypoints I get only get ~2500 points. I think I have tested all parameters (with different values) that may have mattered i.e. ip-per-image, tile-size, ip-per-tile, gain, normalize and still cannot get a single point "found" for first orthophoto. Visual inspection doesn't give any clues as both orthophotos look similar in terms of quality. Apart from SIFT, I have also tried using orb and Harris operator and this also haven't changed the result.
I cannot figure out what is causing such result. Has anyone had similar problem or can explain what may be the cause for not finding IPs?

Below is an example of one of the outputs from console:

ipfind mgr/ESP_012820_ESP_011765_v2.tif --ip-per-image 1000000 --nodata-radius 200 --debug-image 1 --output-folder mgr/run1

Finding interest points in "mgr/ESP_012820_ESP_011765_v2.tif".

Computing 80 ip per tile.

Read in nodata value: 3.4e+38

Detected 23135 raw keypoints!

Found 0 points.

Running sift descriptor generator.

Writing output file mgr/run1/ESP_012820_ESP_011765_v2.vwip

Writing debug image: mgr/run1/ESP_012820_ESP_011765_v2_debug.png with downsample: 0.0261349

Many thanks,
Aleksandra

[Oleg Alexandrov]

I am not sure why I missed this message. For the record though, I don't know why you are having this problem. You may want to see if the left and right images are similar enough. Since they are orttophotos, you can try try to crop them with gdal_translate -projwin to some shared area and try it on it. Maybe it will work better. 

Or you can share some little screenshots with your images (not the full images, those are huge). 

Lastly, I am not sure what you will do with those transformation parameters. Since these are ortophotos, so already textured onto the ground, they are likely not easy to retransform and combine.