New filter: Colorful blobs


(G'MIC staff) #1

I’ve stumbled across an interesting work from Adobe, presented at SIGGRAPH’17, named “Playful palette”.
More info here :slight_smile:

https://research.adobe.com/project/playful-palette-an-interactive-parametric-color-mixer-for-artists/

The idea is to allow an artist to choose colors from a set of colored “blobs”. Summing all these color blobs together generate all shades between colors which are nice color to pick up when coloring a lineart for instance.

I’m currently trying to create something similar in G’MIC. Just a filter that allows the user to create its own blob-based colormap image. It’s far from being finished, but I’ve done a first try.

Filter is currently located in Testing / Ronounours / Joyful colormap, and looks like this:

It heavily uses point() parameters to allow the user to manipulate the color blobs directly over the preview window. I’m planning to allow the choice of the color space used for the color interpolation, as well as a few other improvements (optimizations…).

Do you think this could be useful in a way or another ?


(dumb) #2

This would allow for all sorts of mixing between colours between perhaps any given number of colours. I would up the blob number to 12 or something for now and many think about different interpolation algorithms between colours. Also, yes, definitely add the colour space options.

There can also be some options which depend on the direction of the lines or their x and y coordinates - for example, blending strength/sharpness (rather than just the radius) and blob ellipticity.


(Steve Jacobs) #3

Good idea!


(Boris Hajdukovic) #4

Nice filter @David_Tschumperle!

It could be very useful to create your own gradient filters :smile::

Only one thing: Canvas should match size of layer.


(dumb) #5

Found a bug when using the filter on an image with an alpha channel using the GIMP plugin:

image

Besides that, I’ve quickly made a 12-blob version: https://pastebin.com/9r9WGpTZ

Also can it be extended so that there’s an arbitrary number of blobs rather than a limit of a given number?


(G'MIC staff) #6

Worked hard tonight on this filter, and I guess I have something good enough to be pushed in the main filter tree. So, new filter Colors / Colorful blobs is now available :slight_smile: !

It supports up to 12 color blobs, and you can choose the colorspace used for the interpolation, between sRGB, Linear RGB and Lab.

**EDIT : ** And here’s a video showing the filter in action:


#7

Now, someone can make a blob animation. :wink:


(http://4232.cf) #8

Just wish do something asi like Gseg or Gpos


#9

Looks cool.

I had an idea. Would it be possible to use an input image to set the blob colours? I am imagining that you give it an input image and it finds the most common colours and gives you a nice palette.


(Boris Hajdukovic) #10

Great @David_Tschumperle!

I like transparent background and possibility to choose between different color spaces.
Only one thing: Would it be possible to adjust the canvas to the size of the layer?

Now it looks like this:


(G'MIC staff) #11

No, unfortunately. In order to get a result image that fits what we see in the preview, I have to keep a perfectly square image !


(dumb) #12

It could be an option with a caveat emptor attached to it. Would allow for a bit more wiggle room for those of us who love to experiment with gradients a bit more.