Chas,
The only thing I can see wrong with your equation is the lack of Brackets
Try:
(R*0.2989)+(G*0.587)+(B*0.144)
See Does that help. you should also try the QGIS Raster Calculator, see
if its an issue with the GRASS Plugin/Instillation.
Regards,
Richard
On 17/01/2018 11:52, Chas Sheen wrote:
Richard,
I should have made my initial query clearer.
I am trying to output a black and white geotiff.
Have split the original (landsat) image into RGB images.
When I apply the expression in the capture below, and hit run, nothing
is saved to the results directory.
I’m assuming that my expression or something else in the raster
calculator is wrong?
The final product that I’m after is a xyz grid where z is the
black-white amplitude…which I think should be relatively easy (?) once
I have the black-white image.
Chas Sheen
0448017282
*From:*Richard McDonnell [mailto:richard.mcdonn...@opw.ie]
*Sent:* Wednesday, January 17, 2018 7:13 PM
*To:* Chas Sheen <chassheen...@gmail.com>; qgis-user@lists.osgeo.org
*Subject:* Re: [Qgis-user] Generating black white from RGB landsat
using Raster Map calculator?
Chas,
Two options for splitting RGB into separate images in QGIS.
1. Semi-Automatic Classification Plugin, Preprocessing, Split Raster
Bands
2. Grass r-rgb (Processing Toolbox)
Any one of these tools will split the Raster for you easy enough
Regards,
Richard
On 17/01/2018 00:48, Chas Sheen wrote:
I split the image into R, G, B
Worked out in QGIS wher the Raster map calculator is.
Run...several times
No result foud in Results Directory. It runs quickly then
refreshes inputs and logs to blanks.
I'm new to QGIS....so have probably left out something basic.
Any clues
Displaying image.png
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*_Richard McDonnell_*
*GIS Specialist PgD GIS AssocSCSI*
*OPW FRM Data Management*
*52 Stephens Green, Dublin 2.*
TEL: 01 6476543
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Email Disclaimer: http://www.opw.ie/en/disclaimer/
--
*_Richard McDonnell_*
*GIS Specialist PgD GIS AssocSCSI*
*OPW FRM Data Management*
*52 Stephens Green, Dublin 2.*
TEL: 01 6476543
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