subset an image with vector boundary (not extent)

[Girish Kumar]

Dear all,

           Is it possible to subset an image to the boundary of a vector instead of vector extent(assume that the vector has a single polygon feature). I have tried the rsgislib.imageutils.subset function, but the output image is the subset with vector extent. Kindly give your suggestion




With Warm Regards

Girish

[Pete Bunting [pfb]]

Hi Girish,

You have a couple of options:

1. rsgislib.imageutils.subset2polys() - cuts out an image for each polygon within the shapefile (masking to the polygon shape). However, you might end up with multiple output images and you only provide the output base name so can be more tricky within a longer script where your output will be used in the next stage of processing.

2. using rsgislib.imageutils.subset subset the image to the extent of the shapefile and then mask that file. You can create a raster mask using the rsgislib.vectorutils.rasterise2Image function (the input image is the subsetted image) and apply it with rsgislib.imageutils.maskImage.

I would probably go with the second option as a valid area mask image quite often comes in useful.

Best wishes,

Pete

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[Girish Kumar]

Dear Pete,

          Thank you for your quick reply and suggestions. I have used the gdalwarp function to accomplish it.

gdalwarp -cutline path/to/boundary.shp -crop_to_cutline -dstnodata "0.0" inputraster.tif outputraster.tif

I will try your suggestions also.

Thanks and Regards

Girish