Natron Histogram View

Hello NatronNation,

Some of you may be aware that Natron has a histogram scope already builtin from day. I remember it from version 0.94. The histogram scopes are good in respect because it gives us a display of how the colors are spread across the SMH (Shadows, Mid-tones, and Highlights). And on top of that, it shows us the secondary and tertiary colors that are generated from the addition and subtraction of the RGB channels.

I am using the ColorLookUp node curves to demonstrate how the Histogram displays the colors from the image being process. You can tell where the color lie by the corresponding numbers in the curves editors and in the bottom of the histogram.

If you have any images that may have a certain color cast, you can load it with the ReadOIIO nodes and create the Histogram view. Any where along the Histogram’s SMH spectral grid should show this hue. One thing to remember that RGB Channels values (0 – 225, 0.0 – 1.0) are an additive in RGB color space. As each channels value gets higher, the colors gets brighter. Colors values gets darker in reverse. So it pays to have a 24bit and above monitor to be able to display these large range of colors.

I myself prefers the RGB Parade and Vectorscopes, but nonetheless the Histogram is still a very power scope to have and use.



P.S. Natron is 32bit Float processing. It would be more than helpful to read and understand float math I guessing.


Natron Color Suppress node

Hello Natron VFX Artist,

I have some more information about the new Color Suppression node. This is the feature description “ColorSuppress: Remove a color/tint, or create a mask from that color.” The create a mask from the color is what caught my eye. I have never heard of that being possible or never noticed this implementation in other compositors.

So you know I had to experiment and to my surprise it opened up ideas and possibilities. Now allow me to clear up a few things. Natron has the Despiller node and the Color Suppress node and they both allow you to generate a mask from the Despill color and Suppressed color. The color suppressed node gives you more flexiblity over generating the mask based on the adding and subtracting of hues.

In the attached images, you will see how I use the Color Suppress node as an alternative Despiller function. Another image will so you the settings to generate a mask followed by a ColorLookup node to crush the blacks and expand the whites for the mask. The last image is showing how adjusting a few sliders, I was able to generate a skin tone mask from the green screen image. Which also you can use a ColorLookup node to make any adjustments on the mask.

The node has an output option that allows you to select 3 modes like Image, Alpha, Image and Alpha. You will be familiar with this by using the HSVTool node with the Output Alpha options. Except the HSVTool output alpha are based on the Hue, Saturation, Brightness and the combination of the three in the Min(Hue, Brightness) configuration. See attached images.


Please Enjoy and Create.

Blender Channel Converter Node vs Natron’s Shuffle Nodes

Hello Natron VFX Compositor Users,

Did I mentioned that I am a node based compositing nut job. If not, then yes I am. I have a little back story for you. I was always a fan of Apple Shake. Now that it is no longer in development, it still holds a place in my heart. It was Shake that opened my eyes to node based compositing and later Nuke in its early development from Digital Domain.

In Shake there was a node that was called Reorder. This node is like Nuke’s/Natron’s Shuffle node. It allows you to reorder or break out an image’s channel for surgical processing and combine them back together again. For a while I was using Blender’s converter nodes like Separate RGB and Combine RGB to process and generate spillmaps for my own personal green screen projects. Blender made it a lot easier to separate/combine color channels from the images. When I starting using Nuke for the same effect, I never saw a combine node to pipe the channels back together again. So what I was doing was just generating masks/mattes from the shuffle node and inject them in a mask input of another node.

Today while driving from a hardware store, it popped into my head that I can do the same thing with Natron what I used to do in Blender. This time it only needed to be one node instead of two. The shuffle node can break out channels and it can combine channels. You just have to pipe them in the right order of channels. I will admit it that I had a big duh sign on my forehead.

The images attached are references own how the process would look like between Blender Converter nodes and Natron’s Shuffle node. I’d processed my Bokeh King photo in Blender and I tried to duplicate the look in Natron. I was almost there, but I couldn’t figure out how to recreate the math node from Blender. I will continue to find out how. I just wanted to show this to those who are using Blender for these reasons. Also to let them and as well as everybody else in NatronNation that the process is possible. I am not doing this to attract or pull users from Blender. I am just doing healthy comparisons.

Blender’s Converter Nodes

Blender Convertor Nodes

Natron’s Shuffle Nodes

Natron Shuffle Nodes

Natron has a node called SeExpr1 and another user create a PyPlug called Channel Math. I have no clue how these nodes work or how to use them, but I am sure that they can help process channels in a math equation like Blender’s Math node.