Enhance/smooth raster values caused by noise
I need to enhance or smooth a raster area (GMT grid) where noise is causing problems. The issue is that no raw data are available to do reprocessing, hence, values need to be directly modified/atenuated in the grid. Enclosed please find an image of the original grid with no histogram equalization and with equalization (red = high backscatter values, green = low backscatter values). Grid visualization thanks to the neat MIRONE software.
Any support is welcomed,
RE: Enhance/smooth raster values caused by noise - Added by Joaquim 4 months ago
OK, you are committing the 'Raster' sin typical of GIS talk. What do you have represented exactly? It looks an awfully processed multi-beam bathymetry GRID but you refer to it as "backscatter values" which would put it the IMAGE category.
Mirone has a dedicated tool to 'Iron' a grid over a ROI (smooth) https://sites.google.com/site/mironehowtos/terrain/sooth-multi-beam-grid-on-the-overlapping-swath-zone
but I doubt it would do any visible good in your case. If what you have is a grid and want to make that part 'greener' I only see surgery type operations where you cut that red part (bad SVP data?) "lower it a bit" and insert it back on the main grid. Regarding the short period undulations I can't see anything that can really be done about them, at least without a substantial amount of (programming) work.
RE: Enhance/smooth raster values caused by noise - Added by Gery 4 months ago
thanks for the tip, it didn't help though. I think a surgery type operation is the way to go.