Dear users Co-registration plugin in QGIS,
I wanted to study the spectral signature of a lake. Indeed, I correctly imported the Prisma L2D product under enmap-box v 3.10 (he5 to tif format conversion). The values vary between 0 and 1.
However, Prisma images are always shift with reality (compared to google earth image).
Gooogle earth image :
Prisma image :
So I applied the correction via the QGIS Co-registration plugin (Automated global co-registration) and I have a good result (good correction) :
Prisma image after correction :
However, the values of the pixels before and after correction are not identical. Indeed, the values of the corrected image have multiplied by a factor of 10⁴ compared to the initial image but that is not the problem.
The real problem that the values of the same pixels have been changed too much. See below, I folllow the same pixel (blue outline pixel) and the reflectance (first band) vary from 1155 to 7509 after the correction.
Values on one pixel after correction :
Values on same pixel before correction ;
I have tested all resampling methods of co-registration plugin (cubic, bilinear, nearest neighbour,…) and the results are almost the same and the values are too far from the initial image ("Mode" method not function for me , I don't know why!)
In my opinion, I cannot work with the reflectances of the corrected image. They are too far from reality.
Have you noticed this difference? Is there a method to apply without changing the initial values?
Thank you,
Dear users Co-registration plugin in QGIS,
I wanted to study the spectral signature of a lake. Indeed, I correctly imported the Prisma L2D product under enmap-box v 3.10 (he5 to tif format conversion). The values vary between 0 and 1.
However, Prisma images are always shift with reality (compared to google earth image).
Gooogle earth image :
Prisma image :
So I applied the correction via the QGIS Co-registration plugin (Automated global co-registration) and I have a good result (good correction) :
Prisma image after correction :
However, the values of the pixels before and after correction are not identical. Indeed, the values of the corrected image have multiplied by a factor of 10⁴ compared to the initial image but that is not the problem.
The real problem that the values of the same pixels have been changed too much. See below, I folllow the same pixel (blue outline pixel) and the reflectance (first band) vary from 1155 to 7509 after the correction.
Values on one pixel after correction :
Values on same pixel before correction ;
I have tested all resampling methods of co-registration plugin (cubic, bilinear, nearest neighbour,…) and the results are almost the same and the values are too far from the initial image ("Mode" method not function for me , I don't know why!)
In my opinion, I cannot work with the reflectances of the corrected image. They are too far from reality.
Have you noticed this difference? Is there a method to apply without changing the initial values?
Thank you,