resampling ndvi imagery from float to int

[Girish Kumar]

Dear all,

        There is a requirement to convert an NDVI imagery from 32bit Float to UINT8 bit. Is there any function available in rsgislib to do it? 

One more query-When an rsgislib function completes its execution, what code it returns if it is successful, and what are the standard error codes it return in the event of error.

Thanks and Regards

Girish

[Pete Bunting [pfb]]

Hi Girish,

You’d need to apply and gain and offset to the ndvi (ndvi has a range of -1 to 1), the commands below will do that.

import rsgislib
from rsgislib import imagecalc
imagecalc.imageMath(InputNDVI.kea, OutputNDVI.kea, ‘(b1*100)+100', ‘KEA', rsgislib.TYPE_8UINT)

Best wishes,

Pete

****************************************************
* Dr Pete Bunting
* Reader in Remote Sensing
* Earth Observation and Ecosystem Dynamics Group
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* Aberystwyth University
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[Nathan Thomas]

Ah, yes. I didn't account for that

[Girish Kumar]

Dear Pete,

            Thanks for the suggestion. I have tried it and I was able to run the script successfully. But the created image when open using tuiview, gives the following error.

In method Band_ComputeStatistics, argument 2 of type bool(screenshot attached). I am able to open the output image in normal picture viewer. The same error came earlier also when I tried to open some other image also. What can be the problem?

[Pete Bunting [pfb]]

Hi Girish,

I am not sure on that one - Sam Gillingham might know (cc’d)? Can I suggest you pre-calculate your image statistics.

Either:
rsgislib.imageutils.popImageStats(image, usenodataval=True, nodataval=0, calcpyramids=True)

or

rsgiscalcimgstats.py -i ./inputimg.kea -n 255

-n is the no data value for the image.

Best wishes,

Pete

****************************************************
* Dr Pete Bunting
* Reader in Remote Sensing
* Earth Observation and Ecosystem Dynamics Group
* Department of Geography and Earth Sciences
* Aberystwyth University
* Aberystwyth
* Ceredigion
* SY23 3DB
* UK
*
* Ph: +44 (0) 1970 622615
* Mob: +44 (0) 7917 842743
* Email: p...@aber.ac.uk
* ORCID: http://orcid.org/0000-0002-7435-0148
****************************************************
"Please consider the environment before printing this email or any documents attached”

> On 24 Jan 2017, at 07:08, Girish Kumar <giris...@gmail.com> wrote:
>
> Dear Pete,
>
> Thanks for the suggestion. I have tried it and I was able to run the script successfully. But the created image when open using tuiview, gives the following error.
> In method Band_ComputeStatistics, argument 2 of type bool(screenshot attached). I am able to open the output image in normal picture viewer. The same error came earlier also when I tried to open some other image also. What can be the problem?
>
>
>
>

[Girish Kumar]

Dear Pete,

             Thanks for the suggestion. I have tried it. Now it is fine. After running the command, the tuiview opens the image without error.