Brent,

If your image isn't proprietary, I'd recomend uploading a sample to an image host like photobucket to show us.

Without looking, a very useful tool for me has been color>color to alpha. This will require that you have the alpha channel enabled ( iirc -- posting from my phone -- can be done through layers>transparency>add alpha channel.

If you play around with this feature a little bit you'll figure its strengths and weaknesses out quickly.

Hth, -Stefan Maerz

Actually "color to alpha" adds an alpha channel if it doesn't already have one, so you don't need to do that step.

Seth

On Wed, Jan 25, 2012 at 10:14 AM, Stefan Maerz wrote:

Brent,

If your image isn't proprietary, I'd recomend uploading a sample to an image host like photobucket to show us.

Without looking, a very useful tool for me has been color>color to alpha. This will require that you have the alpha channel enabled ( iirc -- posting from my phone -- can be done through layers>transparency>add alpha channel.

If you play around with this feature a little bit you'll figure its strengths and weaknesses out quickly.

Hth, -Stefan Maerz
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On 01/25/2012 08:56 AM, Brent Shifley wrote:

Morning,

I have been using your app extensively since November. I have come up with a real need to perform in Gimp, but I do not know if Gimp can do it.

What I am trying to do is import a PDF that contains a graphic of radiation patterns from RF towers, along with all roads and other geographical data.

You might want to try extracting the images from your PDF file. If you are lucky, the image you want is stored as a layer in the PDF file and if so, you can get a pristine copy of it. Tools to look at for this might include:

http://www.foolabs.com/xpdf/ http://tinyurl.com/pdf-extract

To import pdf to the GIMP you need a package called Ghostscript: http://sourceforge.net/projects/ghostscript/ If all goes to plan, once this is installed you should be able to drag and drop PDF files into the GIMP. You should get a dialog that asks you to select a page and specify the size and resolution of the image file you are creating.

Once imported, I want to remove all of the roads and unwanted data and keep the radiation pattern. The radiation pattern is in 1 color that dominates the image, and “covers” most of the other unwanted info, almost as a 50% transparency.

Here things get "interesting." Without seeing the actual image it is difficult to prescribe a solution with confidence. It would be helpful to see the PDF file - can you provide a link to it?

I then want to export the radiation pattern, and use it in Google Earth. Additionally, where the radiation pattern is not, have it become completely transparent

I'm not sure what you mean by "use it in Google Earth."

:o)

Steve

On Wed, Jan 25, 2012 at 12:26 PM, Brent Shifley wrote:

This is actually a much simpler graphic than what I would normally be using, but you get the idea.  In as few clicks as possible, I just want the green areas, and want the rest of the graphics transparent.

Hmm - do you have a link to the PDF version? I wonder if perhaps the green areas are vector and/or possibly on their own layer?

Chris

On Wed, Jan 25, 2012 at 12:40 PM, Brent Shifley wrote:

I do not.  Photobucket will not let me upload it either.

OK - for the record: the PDF is just a container for the raster image; no layers or paths*. So the JPEG at Photobucket is pretty much all there is to work with.

I'm sure someone will chime in with a suggested method to isolate those areas...

Chris

* The PDF was generated by Word 2007, and appears to be a JPEG placed in a blank .DOC then exported.

* Brent Shifley [01-25-12 13:41]:

I do not. Photobucket will not let me upload it either.

available:
http://wahoo.no-ip.org/~paka/Test Coverage.pdf

Hi Brent,

This is pretty simple in terms of getting the selected area with this particular image:

Load the image into gimp. Choose the color selection tool.
Set Threshold to 30
Click on the darker green area.
At least for your sample map, that got everything. Note that the color on your sample map is not uniform, which is why the threshold has to be upped from the default (15) to 30. If it doesn't get everything, start over (undo the last operation or exit and start over), up the threshold some more and click on missing areas until you get them all. This works relatively pain-free because there is no similar green anywhere in the image.

Edit/Copy to copy the selected area. Select/None to deselect everything

File/New Click to expand "Advanced Options" Set "Fill with" to transparency
Edit/Paste
You should have just the green areas

Close the window containing the original image

If you don't have the layers dialog open, bring it up. You should see a "Floating Selection" Click the anchor button along the bottom (next to the trashcan) to anchor the pasted stuff into the background.

File/Save

On 1/25/2012 11:26 AM, Brent Shifley wrote:

Here is the url to the file:

http://photobucket.com/Brent_ARK

This is actually a much simpler graphic than what I would normally be using, but you get the idea. In as few clicks as possible, I just want the green areas, and want the rest of the graphics transparent.

Brent Shifley

* Patrick Shanahan [01-25-12 14:24]:

* Brent Shifley [01-25-12 13:41]:

I do not. Photobucket will not let me upload it either.

available:
http://wahoo.no-ip.org/~paka/Test Coverage.pdf

Sorry, that should be:
http://wahoo.no-ip.org/~pat/Test%20Coverage.pdf

On 01/25/2012 03:52 PM, Patrick Shanahan wrote:

http://wahoo.no-ip.org/~pat/Test%20Coverage.pdf

Ah, now I see, sort of...

Just tinkering around, I got better results on the selection after I made a copy of the base layer (i.e. original image) and used the Colors > Hue/Saturtation tool with the Green segment turned on, to crank up the saturation and reduce the brightness of the green area to enhance contrast. (Trying to rotate the hue of the red roads to green was disappointing - they are more brown and black than red.) The Color Select tool then has an easier time sorting out those faint edges.

I took that selection, copied and pasted it as a new layer, put a new while layer under that and merged down. As for how to remove the white lines where roads, streams, scale, etc. were, the first thing that occurs to me is to turn on the Smudge tool, set its "rate" very high (why not 100%), and start smearing.

To get your transparent overlay, duplicate the modified green and white layer, and do Colors > Color to Alpha to make the white go away. This will also make the green semi-transparent - and at this point, the extra contrast introduced earlyer may accidentally prove beneficial. I'm not sure where this overlay will go, but if it's into an image, just open same, drag the last mentioned layer into it, scale to fit, and adjust its transparency, saturation, etc as required.

Or something like that. Always more than one way...

:o)

Steve

Hi Brent,

I expect that you want more than just the green selection - you want what the green selection would be if there were no roads/other data overlaid, right?

The best way I can do this in a reasonably automated fashion is:

1) Extract the roads as a selection 1-a) Colors->Components->Decompose, RGB, delete all but Green channel 1-b) Levels, adjust so that only roads are black and everything else is white (be fairly generous with what you call a road - a little slop is better than too little road)
1-c) Copy (control-C)
2) Back in original image, Create a new layer, transparent, select it as active layer.
3) Quick Mask
4) Paste (Control-V), Anchor (Control-H) 5) Quick Mask off
6) Select->Invert
6) Select->Grow (2)
7) Fill with white (drag from toolbox) 8) Select->None

At this point you should have 2 layers; the top has all the roads covered by white, and the bottom your original map image

9) Run the G'MIC plug-in (probably a separate download, google for it), select Region Inpainting, OK with defaults Wait a few seconds, and you now have a map that has just green and grey regions with no red or hints of roads. 10) Delete the top layer that's no longer useful.

At this point the problem of extracting what you really want (an in-filled green image) can begin. Its a bit messy with your image due to compression artifacts, but you can get decent results doing a Select by Color with threshold=28, then Select->Shrink(1) followed by Select->Grow(1) to get rid of the smallest objects, but there's still some garbage in the final results. Color-To-Alpha with white and then black can also produce a semi-transparent image, but its got a lot of noise (other colors existed in the image that are now really noticeable). Experimenting with Posterize or other color reduction/smoothing may be beneficial too, just to remove compression artifacts.

This isn't suitable for anything scientific - the infill process is certainly making guesses based on surrounding data which just doesn't exist in the image - but hopefully it'll get you at least part of the way to where you want to be. You could script most of this once you find values that work for you (though figuring out the G'MIC plug-in may be tough as it just takes a string input in non-interactive mode).

Happy GIMPing,

Seth Burgess

On Wed, Jan 25, 2012 at 7:56 AM, Brent Shifley wrote:

Morning,****

** **

I have been using your app extensively since November. I have come up with a real need to perform in Gimp, but I do not know if Gimp can do it.****

** **

What I am trying to do is import a PDF that contains a graphic of radiation patterns from RF towers, along with all roads and other geographical data. Once imported, I want to remove all of the roads and unwanted data and keep the radiation pattern. The radiation pattern is in 1 color that dominates the image, and “covers” most of the other unwanted info, almost as a 50% transparency. I then want to export the radiation pattern, and use it in Google Earth. Additionally, where the radiation pattern is not, have it become completely transparent****

** **

Can you tell me how to perform this feat using Gimp? ****

** **

Brent Shifley****

AWIN Support****

** **

Arkansas Wireless Information Network (AWIN)****

501-683-1798****

AWIN.Operations@arkansas.gov****

** **

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Seth, you're way ahead of me with your thoughts and methods on this, but I might offer an easier, but less precise, alternative.

As you point out, Brent probably wants to include those areas the road obscures. Since the roads are pretty narrow, one could get fairly accurate results by simply selecting the green, growing the selection by 2, and shrinking it by 2. That would force inclusion of the roads in areas they traverse. It would have the unwanted side-effect of also including small non-green areas of approximately 4 pixels in diameter. Whether that would matter or not I'll let Brent chew on, but in looking at the sample map it's pretty good.

Gary

On 1/25/2012 3:10 PM, Seth Burgess wrote:

I expect that you want more than just the green selection - you want what the green selection would be if there were no roads/other data overlaid, right?

The best way I can do this in a reasonably automated fashion is:

1) Extract the roads as a selection 1-a) Colors->Components->Decompose, RGB, delete all but Green channel 1-b) Levels, adjust so that only roads are black and everything else is white (be fairly generous with what you call a road - a little slop is better than too little road)
1-c) Copy (control-C)
2) Back in original image, Create a new layer, transparent, select it as active layer.
3) Quick Mask
4) Paste (Control-V), Anchor (Control-H) 5) Quick Mask off
6) Select->Invert
6) Select->Grow (2)
7) Fill with white (drag from toolbox) 8) Select->None

At this point you should have 2 layers; the top has all the roads covered by white, and the bottom your original map image

9) Run the G'MIC plug-in (probably a separate download, google for it), select Region Inpainting, OK with defaults Wait a few seconds, and you now have a map that has just green and grey regions with no red or hints of roads. 10) Delete the top layer that's no longer useful.

At this point the problem of extracting what you really want (an in-filled green image) can begin. Its a bit messy with your image due to compression artifacts, but you can get decent results doing a Select by Color with threshold=28, then Select->Shrink(1) followed by Select->Grow(1) to get rid of the smallest objects, but there's still some garbage in the final results. Color-To-Alpha with white and then black can also produce a semi-transparent image, but its got a lot of noise (other colors existed in the image that are now really noticeable). Experimenting with Posterize or other color reduction/smoothing may be beneficial too, just to remove compression artifacts.

This isn't suitable for anything scientific - the infill process is certainly making guesses based on surrounding data which just doesn't exist in the image - but hopefully it'll get you at least part of the way to where you want to be. You could script most of this once you find values that work for you (though figuring out the G'MIC plug-in may be tough as it just takes a string input in non-interactive mode).

Happy GIMPing,

Seth Burgess

THANK YOU!

I have been burning brain cells on this for a while. I do have one final question. Like in the case where there was green in all sorts of places, how could I go and change all the green areas to any color that I want, in only a couple of clicks?

File/Save

On 1/25/2012 11:26 AM, Brent Shifley wrote:

Here is the url to the file:

This is actually a much simpler graphic than what I would normally be using, but you get the idea. In as few clicks as possible, I just want the green areas, and want the rest of the graphics transparent.

Brent Shifley

The great thing about Gimp is there is always another way.

Have to confess, my first thoughts were with the G'mic plugin but maybe a better way for your specific case is

Convert the image to indexed with a small number of colours Edit the colour map so anything non green is (say) white Back to RGB mode and colour-to-alpha to remove the white.

Short demo - 2 mins here http://youtu.be/xVy4rwoye6o

Brent Shifley writes:

THANK YOU!

I have been burning brain cells on this for a while. I do have one final question. Like in the case where there was green in all sorts of places, how could I go and change all the green areas to any color that I want, in only a couple of clicks?

Colours → Colourise, works on the current selection or all if none is selected. http://docs.gimp.org/2.6/en/gimp-tool-colorize.html

Hi Brent,

For painting, try this:

Once you have the area selected, by whatever means:

Create a new layer containing only the selected areas, with a transparent background in other areas: Edit/Copy (ctrl-C on windows)
This will copy everything in the selection (green areas, roads, etc) Create a new layer.
Make sure "Transparent" is selected for background type when creating it.
The layer will become the currently selected layer Edit/Paste (ctrl-V on windows)
Click on the eyeball of original background in the layers dialog The background will disappear;
you will be left with only your new layer being visible. The transparent parts will be a grey checkerboard. At this point, nothing is selected.

Select everything except the transparent area. Click on the "Select by Color" tool Uncheck the "Select transparent areas" check box in the tool's options Set the threshold to 255
Click anywhere in the image not on the transparent background. The selection will be outlined with an alternating black-and-white, blinking line.

Fill the selection with the color you want: Select the color you want to use: Double-click on the foreground color (upper square, usually black, in lower left corner of the toolbox) A dialog for choosing colors should appear. Note the box which shows "current" and "old" color Tweak the sliders or the color choice tool (object in left square) to get the color you want shown as the "current" color Click ok.
Note the upper square showing the foreground color in the toolbox should now have the color you want to paint with. Click on the bucket-fill tool
Make sure "FG color fill" is selected in the tool's options Make sure "Fill whole selection" is selected in the tool's options Click anywhere in the selection. It should all change to a solid color with the new color; transparent areas, outside the current selection, should still show a gray checkerboard.
If you want the colored part to be partially transparent, Use the "Opacity" slider for the layer.

Save the result.

If you find the final area covers more than you thought it would, it is probably because the original selection contained stuff you weren't aware of.
This will happen if you leave any of "Anti-aliasing" or "Feather edges" or "Select transparent areas" or "Sample merged" checked when making your original selection.

Gary

On 1/26/2012 1:57 PM, Brent Shifley wrote:

Again I want to say thanks to all of you that helped me. I have another 77 images to process, and what you have sent me helped a lot.

I was not able to follow the trick for "painting" 100+ different areas the same color, at the same time. As I stated before I am an absolute newbie to Gimp, and sometimes have need little "extra" help in understanding how to do a step/process/procedure, and why. Any other help would be appreciated.

Hi,

one final answer: If you have to process a lot of files I would recommend you to wirte a script, especially if the same tasks have to be performed very often.
GIMP-standard-scripts are written in scheme. I prefer perl-GIMP. If I can help you with this, let me know.

Bernd

Gary Aitken schrieb:

Hi Brent,

For painting, try this:

Once you have the area selected, by whatever means:

Create a new layer containing only the selected areas, with a transparent background in other areas: Edit/Copy (ctrl-C on windows)
This will copy everything in the selection (green areas, roads, etc) Create a new layer.
Make sure "Transparent" is selected for background type when creating it.
The layer will become the currently selected layer Edit/Paste (ctrl-V on windows)
Click on the eyeball of original background in the layers dialog The background will disappear;
you will be left with only your new layer being visible. The transparent parts will be a grey checkerboard. At this point, nothing is selected.

Select everything except the transparent area. Click on the "Select by Color" tool Uncheck the "Select transparent areas" check box in the tool's options Set the threshold to 255
Click anywhere in the image not on the transparent background. The selection will be outlined with an alternating black-and-white, blinking line.

Fill the selection with the color you want: Select the color you want to use:
Double-click on the foreground color (upper square, usually black, in lower left corner of the toolbox) A dialog for choosing colors should appear. Note the box which shows "current" and "old" color Tweak the sliders or the color choice tool (object in left square) to get the color you want shown as the "current" color Click ok.
Note the upper square showing the foreground color in the toolbox should now have the color you want to paint with. Click on the bucket-fill tool
Make sure "FG color fill" is selected in the tool's options Make sure "Fill whole selection" is selected in the tool's options Click anywhere in the selection. It should all change to a solid color with the new color; transparent areas, outside the current selection, should still show a gray checkerboard.
If you want the colored part to be partially transparent, Use the "Opacity" slider for the layer.

Save the result.

If you find the final area covers more than you thought it would, it is probably because the original selection contained stuff you weren't aware of.
This will happen if you leave any of "Anti-aliasing" or "Feather edges" or "Select transparent areas" or "Sample merged" checked when making your original selection.

Gary

On 1/26/2012 1:57 PM, Brent Shifley wrote:

Again I want to say thanks to all of you that helped me. I have another 77 images to process, and what you have sent me helped a lot.

I was not able to follow the trick for "painting" 100+ different areas the same color, at the same time. As I stated before I am an absolute newbie to Gimp, and sometimes have need little "extra" help in understanding how to do a step/process/procedure, and why. Any other help would be appreciated.

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Colours → Colourise, works on the current selection or all if none is selected. http://docs.gimp.org/2.6/en/gimp-tool-colorize.html

Or use colors -> levels. I find colorize to be counter intuitive when adjusting colors. However, with levels it's easy to adjust the red/green/blue levels till the color comes out right. Then the next time you use the levels dialog, just use the first dropdown to use your last settings. Pretty easy to use the same color over and over. Also preserves variations in colors better than colorize (which reduces all colors to grayscale first, essentially).

-James