New G'MIC filter 'Rendering / Gradient [from line]'

GnuTux · **Posted:** Thu Oct 10, 2013 6:24 pm **(#21)**

molly wrote:

Here is my first try.

Looks cool, Molly.

The problem I'm having with this filter is what I'm trying to show in my previous post. As you can see, I have only one section of the blind selected and the preview looks right, but when the gradient is generated, it duplicates that section several times across the gradient, as shown at the bottom. I would have expected G'MC to generate only the segment I selected, and extend that across the entire gradient, but instead, it duplicated it about six times across the gradient.

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

Well maybe it will be fixed soon, it has come a long way since the beginning so we are getting there. To me the less steps the better, to acquire a nice smooth gradient. Can it not be done by using the elastic tool like the gradient tool to select the part of the image we want to use? It would be so much easier and with less fiddling with numbers.
Wouldn't you be able to fix that with tweaking the Sampling and Intra-shades

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

PhotoComix wrote:

This is too cool !

:ninja

by Ronounours (and even before Gnu Tux, Molly ...everybody had ninja me while i was correcting typos before submit

for the first time a enhancement request was fulfilled even before be posted:
new "Intra shades" control sound as exactly what i was asking here below

It would be possible add a control for colors transition softness ?

As from hard ( i.e if black follow white would be a clear jump with no intermediate grays )
from very soft (white will gradually merge with several intermediate grays )

not sure if there is a limit to numbers of colors supported by gimp gradients ,( i mean a limit lower then the RGB colours ),
but whatever is the limit, a similar option may use the max supported number of colours when requested gradient with soft transitions
----------------------------------------------------------

EDIT

Already solved ! :yes

Awe, So sorry PC... I have that happen all the time too. I try to make a quck tute for someone that asks a question and by the time I get it finished ready to post, I get ninja'd several times.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

GnuTux : that's weird. I've done a quick test on my side, with the same kind of images as yours. Everything is working as expected.
May I ask which version of G'MIC you are using ?

Attachment:

gmic_nobug.png [ 113.24 KiB | Viewed 4743 times ]

GnuTux · **Posted:** Fri Oct 11, 2013 3:37 am **(#25)**

Thanks for testing this out, Ronounours.

I see what is happening now. When I zoom the preview. I get the correct gradient in the "gradient preview" box (see below). However, when I click OK and the gradient is actually generated, it doesn't use the gradient I see in the preview. It reverts back to the non-zoomed version of the image and samples from there. That is not what I expected from the gradient preview but now that I know what is happening, I can work around it.

You can see that what appears in the gradient preview is not what gets generated. One just needs to be aware that the "gradient preview" is only reliable when not zoomed.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Haaa yes, that explains it indeed !
You should *never* push the preview zoom buttons

Each G'MIC filter is trying to set the correct zoom factor by itself, and modify it will modify the preview accuracy. I'd even like to disable those zooming buttons one day.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

In fact, I've also pushed a new version of the filter, with even more options for sorting the final color gradient :

Attachment:

gmic_gradient_from_line.png [ 254.07 KiB | Viewed 4730 times ]

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

Very nice work David.
About the Zoom, Isn't it just as easy to use the zoom at the bottom on your gimp page to get a better look at what you are working on? I use that a lot for these things.

GnuTux · **Posted:** Fri Oct 11, 2013 5:44 am **(#29)**

Thanks for the additional settings, Ronounours.

@Molly - In this case, you must use the G'MIC preview to see which section of the image you are actually sampling for a gradient. If you are using a large image and want to sample a gradient from a small section, you will have to crop the image down (and possibly resize the cropped section up to fill the preview window) before you'll be able to accurately sample that section.

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

Thank you Tux, I didn't know that.

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

GnuTux, another possibility is to first select a sub-region (no need to explicitely crop), then run the G'MIC filter on it.

GnuTux · **Posted:** Fri Oct 11, 2013 12:43 pm **(#32)**

Yes! That works, unless I need to size up the selection, which is not a problem. With all of your enhancements, this has became a very useful filter.

:tyspin

for your efforts!

GnuTux · **Posted:** Fri Oct 11, 2013 1:03 pm **(#33)**

Just updated and got the new version.

What happened to Intra shades? That was one of the most useful features. :hoh

What does length do?

molly · **Joined:** Apr 07, 2010 **Posts:** 14182

I am glad you asked that. I had the same problem, I couldn't figure it out how to select just a short little stroke of the beak, head and neck I couldn't shorten the dotted selection. Nothing happens when I play with the length slider. It worked okay for me yesterday on the old setup. I thought this time I would wait for some one else to ask so I will know if it is just me...OR NOT. I ended up with the long gradient with only part of it filled and the rest transparent.

Erisian · **Posted:** Fri Oct 11, 2013 1:24 pm **(#35)**

length is intra shades tux.

GnuTux · **Posted:** Fri Oct 11, 2013 1:34 pm **(#36)**

Thanks, Erisian, I see now that it is actually an enhanced intra-shade function. :yes

Calling it "length", along with the new comment, was kinda confusing.

Graechan · **Posted:** Fri Oct 11, 2013 11:17 pm **(#37)**

Both these new Gradient filters can be combined for Unique Text Logos

Ronounours · **Joined:** Jan 03, 2011 **Posts:** 1656

Very cool !
I'm really happy to see that these filters can be used for practical applications.
Thanks.

Graechan · **Posted:** Sat Oct 12, 2013 8:18 pm **(#39)**

David the uses of these new filters is easy to explain as I have below↓ for 'custom shape'
My only problem is the outer edge of the gradient is a bit rough can that be fixed within GMIC

Settings for a 10px outer border are simple

Pat625 · **Joined:** May 12, 2015 **Posts:** 4693

How do you save a gradient from line made with the G'MIC filter. The Save gradient prompt will not take anything I write there. Refreshing the gradients in GIMP does nothing.