Help Document?

[pingyangtiaer]

I found this tool very impressive and tried to use it. However, I couldn't quite understand it very much. Is there a detail document for it? e.g. When I looked into generating the pseudo invariant feature pixels (pif.py), I don't quite understand the lines: for full_filename, cropped_filename in zip(full_candidate_filenames, candidate_filenames): subprocess.check_call(['gdal_translate', '-projwin', '545000', '4136000', '601000', '4084000', full_filename, cropped_filename])

for full_filename, cropped_filename in zip(full_reference_filenames, reference_filenames): subprocess.check_call(['gdal_translate', '-projwin', '545000', '4136000', '601000', '4084000', full_filename, cropped_filename])

What does it exactly mean? Appreciate your help. Peter

[arincos]

Hello Peter,

Thanks for using the tool!

Yes, sadly the docmentation is a bit lacking and I'll work on improving that.

With regards to that specific bit of code, it uses the gdal_translate utility to crop the full sized Landsat images to their common area (manually specified by the geographic coordinates in -projwin) so that both the candidate and reference pixels overlap.

I hope this helps.

Best regards,

Arin

[pingyangtiaer]

Thank you Arin, Why it should be manually specified?I think it will be nice to create the common area automatically. How do you pre-process the imagery before generating the pseudo invariant feature pixels, I noticed that the candidate and reference image must be align to each other, most of the case this requirement are not meet. I suggest a process which can extract the overlapping area between the two imagery and generate the pseudo invariant feature pixels based on the extracted area and then apply the PIF table to the candidate imagery. Do you have this process already, will you able to incorporate into the existing code? Looking forward to hearing from you. Thanks,

[arincos]

Hello,

Sorry for the delay in replying!

They were just manually specified for that specific example but there could be a function to automatically crop the candidate and reference imagery so that they align with each other (e.g. using gdal or something). At the moment, this kind of feature isn't on the table but if I get time I can try to scope something out. I can definitely see how that kind of function could be helpful.

Thanks,

Arin

[Neelumgithub]

Hello @arincos, I am intending to make use of this tool to normalize set of Landsat-8 OLI bands prior to perform spectral change detection. However, being novice to coding I am unable to utilise the script. I am supposed to work in GUI, specifically in QGIS. Is there any way to make this tool run over there? I don't see documentation for its use in any of GIS program. It would be great if you consider creating a plugin for QGIS for its wider application and due appreciation as well.