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Topic: Discard/Replace NaN values (missing values)

Dear Sebastian,

I am having Landsat 8 Images to estimate surface velocity of a glacier.

I am facing problem in using the Discard/Replace Image Values Tool.

1) Replace filtered values by (empty for NaN) : How to find out this value?

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Re: Discard/Replace NaN values (missing values)

Dear Mitkari,

The "Discard/Replace Value" tools allows you to replace the value of all pixel that are outside a range that you specify with a value of your choice. For instance, assume you have an image with positive and negative values, and you would like to set all the negative values to "0". This is typically the tool that you would use. If you want to replace all the negative values with a NaN, just leave the field "Replace filtered values by (empty for NaN)" empty.
Now if you want to replace the pixels with a value that is dependend on some criteria (neighboring, etc...) then the "Discard/Replace Value" tool is not appropriate. You need a filter tool (e.g.,Non-Local Mean Filter) - see also ENVI filter tools.

Francois

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Re: Discard/Replace NaN values (missing values)

Thank so much Francois