[Qgis-user] Problem with raster calculator

[Ricardo Filipe Soares Garcia da]

Hi Jesus

Perhaps your input layer has no values that match the >= 73 condition?

I can reproduce this behaviour if I use a layer in which pixel values go up
to 50 and I ask for pixels >= 60.

Otherwise, if the input layer has values above the threshold, it seems
strange and I cannot seem to reproduce it here (QGIS 2.8.1)




On Wed, Apr 15, 2015 at 8:58 AM, Jesus Munoz <jesusmunozserrano at gmail.com>
wrote:

> Good morning list!!
>
> I am trying to do a cloud mask for a Landsat image based on the values of
> the pixels where the clouds are found. I am using the raster calculator for
> this purpose by introducing the expression:
>
>                 (“Band 1 layer name" >= 73) * "Band 1 layer name”
>
> So basically, I am trying to obtain a layer in which all pixels with a
> value lower than 73 are removed.
>
> However, after calculating this expression I only get an empty raster
> layer, only visible in the layers panel and populated only by “nan” values.
> Does anybody know what am I doing wrong???
>
> Jesus
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>



-- 
___________________________ ___ __
Ricardo Garcia Silva
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