Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
Chas, If I have a color GEOTIFF and I want to show or save it as a grayscale GEOTIFF, I use one of these 2 solutions. Depending on the control you want on the color to grayscale conversion it might also be a solution for you. Solution 1: If the only thing you want to do is show a colour geotiff in grayscale, you can just change the properties of the layer. In the layer properties you go to the tab “Style”. Under “Color rendering” you will find the option “Grayscale”. By default the option will be set to “Off”, but you can change it to turn grayscale on. Try one of the three options to see what fits your image best. After that you can also change the values of “Brightness” or “Contrast” to get the best result. This way you won’t change anything in your source file and it won’t save a grayscale tiff, but it will just show your raster file as grayscale in QGIS. Solution 2: If you want to end up with a geotiff file that has the same information in grayscale I usually use some graphical software in the process, but for that you can’t use a GeoTiff, because you would loose the georeference information of the file. Therefore I use the following steps: 1. Save your geotiff file as TIFF-file with a TFW file: a. Right click on your source geotiff file in the layers panel. b. Select Save As… c. Select Rendered image as Output Mode d. Select Gtiff as format e. Deselect “Add saved file to map” f.Under “Create Options” click on the + button to add an option. For the newly added option you have to type TFW as “Name” and YES as “Value” (double click in the newly created Option cell to type in it). g. Click on the “Browse…” button to select a name and location for your grayscale TIFF file. h. Click on the “OK” button 2. Open the newly created TIFF file in graphical software like XnView, IrfanView or GIMP. Change the image in that software to grayscale and save the file. 3. Add the newly created TIFF file back to QGIS 4. Save your newly created TIFF file as a GeoTIFF file: a. Right click on your newly created TIFF file in the layers panel. b. Select Save As… c. Select Rendered image as Output Mode d. Select Gtiff as format e. Click on the “Browse…” button to select a name and location for your grayscale GEOTIFF file. f.Click on the “OK” button Michel Van: Qgis-user [mailto:qgis-user-boun...@lists.osgeo.org] Namens Chas Sheen Verzonden: woensdag 17 januari 2018 14:33 Aan: 'Micha Silver' <tsvi...@gmail.com>; qgis-user@lists.osgeo.org Onderwerp: Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator? Mike, So everything in the capture below of the Raster calculator should work? I cannot find any output. I’m in Perth, Australia so home now and away from the office and QGIS, but would like to get it working tomorrow. How do apply a grayscale to a raster? As I said, I’m new to QGIS Chas Sheen From: Micha Silver [mailto:tsvi...@gmail.com] Sent: Wednesday, January 17, 2018 8:39 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? Hello Chas On 01/17/2018 01:52 PM, Chas Sheen wrote: Richard, I should have made my initial query clearer. I am trying to output a black and white geotiff. It's still not clear what you are asking. AFAIK, there's no such thing as a "black and white geotiff". You can apply any color table you want to any raster. You can apply a gray scale to any of the landsat bands. If you are trying to create a new raster from the three RGB bands using some expression, that should work. You can use either of three tools: the built in QGIS raster calculator, or thru the Processing toolbox there's SAGA Raster calculus and the GRASS module r.mapcalculator. Again, none of this has anything to do with coloring. After running the raster calculator, you can color the result with a gray scale color table, a red color table, or any other color ramp you choose. 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. After you running the calculator expression, then you can save the result in many formats, including gridded XYZ, ArcINFO ASCII, or many others, using the gdal_translate tool. This is under the Raster->Conversion menu. 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><mailto:chassheen...@gmail.com>;
Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
Mike, So everything in the capture below of the Raster calculator should work? I cannot find any output. I’m in Perth, Australia so home now and away from the office and QGIS, but would like to get it working tomorrow. How do apply a grayscale to a raster? As I said, I’m new to QGIS Chas Sheen From: Micha Silver [mailto:tsvi...@gmail.com] Sent: Wednesday, January 17, 2018 8:39 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? Hello Chas On 01/17/2018 01:52 PM, Chas Sheen wrote: Richard, I should have made my initial query clearer. I am trying to output a black and white geotiff. It's still not clear what you are asking. AFAIK, there's no such thing as a "black and white geotiff". You can apply any color table you want to any raster. You can apply a gray scale to any of the landsat bands. If you are trying to create a new raster from the three RGB bands using some expression, that should work. You can use either of three tools: the built in QGIS raster calculator, or thru the Processing toolbox there's SAGA Raster calculus and the GRASS module r.mapcalculator. Again, none of this has anything to do with coloring. After running the raster calculator, you can color the result with a gray scale color table, a red color table, or any other color ramp you choose. 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. After you running the calculator expression, then you can save the result in many formats, including gridded XYZ, ArcINFO ASCII, or many others, using the gdal_translate tool. This is under the Raster->Conversion menu. Chas Sheen 0448017282 From: Richard McDonnell [mailto:richard.mcdonn...@opw.ie] Sent: Wednesday, January 17, 2018 7:13 PM To: Chas Sheen <mailto:chassheen...@gmail.com> <chassheen...@gmail.com>; qgis-user@lists.osgeo.org <mailto: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 QGISso have probably left out something basic. Any clues ___ Qgis-user mailing list Qgis-user@lists.osgeo.org <mailto:Qgis-user@lists.osgeo.org> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- Richard McDonnell GIS Specialist PgD GIS AssocSCSI OPW FRM Data Management 52 Stephens Green, Dublin 2. TEL: 01 6476543 <http://www.opw.ie/> Email Disclaimer: http://www.opw.ie/en/disclaimer/ ___ Qgis-user mailing list Qgis-user@lists.osgeo.org <mailto:Qgis-user@lists.osgeo.org> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- Micha Silver Ben Gurion Univ. Sde Boker, Remote Sensing Lab cell: +972-523-665918 ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
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 QGISso have probably left out something basic. Any clues Displaying image.png ___ Qgis-user mailing list Qgis-user@lists.osgeo.org <mailto:Qgis-user@lists.osgeo.org> List info:https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe:https://lists.osgeo.org/mailman/listinfo/qgis-user -- *_Richard McDonnell_* *GIS Specialist PgD GIS AssocSCSI* *OPW FRM Data Management* *52 Stephens Green, Dublin 2.* TEL: 01 6476543 <http://www.opw.ie/> 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 ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
Hello Chas
On 01/17/2018 01:52 PM, Chas Sheen
wrote:
Richard,
I should
have made my initial query clearer.
I am
trying to output a black and white geotiff.
It's still not clear what you are asking. AFAIK, there's no such
thing as a "black and white geotiff". You can apply any color
table you want to any raster. You can apply a gray scale to any of
the landsat bands.
If you are trying to create a new raster from the three RGB bands
using some _expression_, that should work. You can use either of
three tools: the built in QGIS raster calculator, or thru the
Processing toolbox there's SAGA Raster calculus and the GRASS
module r.mapcalculator.
Again, none of this has anything to do with coloring. After
running the raster calculator, you can color the result with a
gray scale color table, a red color table, or any other color ramp
you choose.
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.
After you running the calculator _expression_, then you can save
the result in many formats, including gridded XYZ, ArcINFO ASCII,
or many others, using the gdal_translate tool. This is under the
Raster->Conversion menu.
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.
Semi-Automatic Classification Plugin,
Preprocessing, Split Raster Bands
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 QGISso have probably left out something basic.
Any
clues
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
--
Richard McDonnell
GIS Specialist PgD GIS
AssocSCSI
OPW FRM Data Management
52 Stephens Green, Dublin
2.
TEL: 01 6476543
Email Disclaimer: http://www.opw.ie/en/disclaimer/
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
--
Micha Silver
Ben Gurion Univ.
Sde Boker, Remote Sensing Lab
cell: +972-523-665918
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
Re: [Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
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 QGISso have probably left out something basic. Any clues ___ Qgis-user mailing list Qgis-user@lists.osgeo.org <mailto:Qgis-user@lists.osgeo.org> List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- Richard McDonnell GIS Specialist PgD GIS AssocSCSI OPW FRM Data Management 52 Stephens Green, Dublin 2. TEL: 01 6476543 <http://www.opw.ie/> Email Disclaimer: http://www.opw.ie/en/disclaimer/ ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
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 QGISso have probably left out something basic. Any clues Displaying image.png ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user -- *_Richard McDonnell_* *GIS Specialist PgD GIS AssocSCSI* *OPW FRM Data Management* *52 Stephens Green, Dublin 2.* TEL: 01 6476543 OPW - Ag féachaint don am atá le teacht - Ag caomhnú ón am atá thart OPW - Looking to the future - Caring for the past *** Email Disclaimer: http://www.opw.ie/en/disclaimer/ ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
[Qgis-user] Generating black white from RGB landsat using Raster Map calculator?
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 QGISso have probably left out something basic. Any clues [image: Displaying image.png] ___ Qgis-user mailing list Qgis-user@lists.osgeo.org List info: https://lists.osgeo.org/mailman/listinfo/qgis-user Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user
