[mapserver-users] raster tiling of non rectangular images

[victor valencia]

Hi:

I need  to create a tileindex of several non-rectangular raster images. I tried GdaltIndex, but produces rectangular polygons including the non-data (Null) pixels. 
These images i have are Landsat 7 saved as *.img, *.tiff, *.Sid. 
These images are rhomboidal. Since the file is rectangular there is an area with no valid pixels (non-data or Null). I need a boundary polygon that exclude this pixels. 

I found an arcview 3x extension named Grid to Valid-pixel Polygon Catalog w Stats, that creates a boundary polygons of the valid pixels, but works just with Grid images. I could change the format of my images but this is very very time consuming. 

 Is there any script to create irregular bounding polygons (non-rectangular) from the valid pixels for several images?

Best regards

Victor



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