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I want to convert a raster .tif file into a raster .asc file in QGIS. For this, I am selecting Raster -> Conversion -> Translate option. I am getting the output .asc file.

But, both the minimum and maximum pixel values of this raster file is displayed as 1.79769e+308 and I am not able to see any data in this output file.

It is true that there is no data available in this raster file. But, even in that case, the minimum and maximum pixel values will not be like this.

Unfortuantely, I am getting very crazy pixel values : Min = 1.79769e+308 and Max = 1.79769e+308.

Whenever I do any type of geoprocessing in QGIS with a raster which has no data / feature, I am getting the pixel values as Min = 1.79769e+308 and Max = 1.79769e+308.

What is the exact reason for this issue and how can I solve this ?

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  • Maybe you tell QGIS to export raster from an area that is outside of your data and all that you get is NoData.
    – user30184
    Feb 12, 2018 at 17:09
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    @user30184 It is true that the output raster is a NODATA which means it has no data or features present in it. But, even in that case, the Min and Max pixel values will not be like Min = 1.79769e+308 and Max = 1.79769e+308. Why, if some raster is having NoData, the Min and Max pixel values are Min = 1.79769e+308 and Max = 1.79769e+308. ? What is the exact reason behind this ?
    – Sreeraj
    Feb 15, 2018 at 11:06
  • I do not even try to guess without having some test data and detailed instructions for reproducing the issue.
    – user30184
    Feb 15, 2018 at 14:36
  • This seems to have been marked as fixed, but I still have the problem in QGIS 3.4 issues.qgis.org/issues/18764
    – Shawn
    Dec 18, 2018 at 3:30

1 Answer 1

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Another possibility is that you are working on renamed layers. When I did raster calculations I often got faulty layers (1.79769e+308 values) generated in QGIS 3x, without any error. I tested on QGIS 3.2 and 3.4.3.

There is a raster calculator bug caused by renaming of layers that only was completely fixed on 2019-01-02. See issue 20601, it is fixed, but has yet to make it to a stable build. As a workaround, in 3.4.3, the Gdal raster calculator in the Processing Toolbox seems to work, as is the one in the main menu "Raster - Raster Calculator"

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  • Welcome to GIS SE! As a new user, please take the short tour to learn about this site's focused Q&A format. Then please consider building on your answer by including software version numbers and/or bug numbers and links to further information.
    – Andy
    Jan 11, 2019 at 14:39

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