The Artist's Helper

Learn to paint with the Artist's Helper

The Artist's Helper is an application that can help you learn to paint.

… paint with real paint, oils or acrylics or whatnot, not digital painting. It's a digital helper for physical art.

Laika's reference image painting
Reference image help from The Artist's Helper Final painting

Painting is simple. Just put the right colours in the right places.

Our helper will look over our shoulder and give us advice.

It can help us choose the colours we need, tell us how to mix them and show us where to put them. It will watch our progress and will steer us back on track if we go wrong.

Let me do a rough sketch to start you off. I can print it scaled to the size of your canvas over multiple pages with page alignment markings for easy tracing or transfer.
I see you have drawn her left eye a little bit too low. You should correct that before you continue any further. It'll be harder to correct once you've started painting.
Her skin tone seems a bit too cool, consider a warm glaze. The background could be a little cooler though and more desaturated to add a sense of distance.
You can mix the colour for the folds in her dress with your cadmium red and a little of your quinacridone magenta.

Well, not exactly in those words, but close enough.

  • Our helper looking over our shoulder is actually us importing photos of our work-in-progress.
  • Its advice is the interactive charts, graphs and images it creates for us.
  • If we show it our reference photo then it can use edge detection to create a sketch and print it out scaled to our physical canvas for easy transfer.
  • From the reference it will help us work out what colours we need
  • … and if we show it a photo of our available paints it can show us how to mix those colours
  • … and if we then show it our trial mixes it will advise us how close we are and what else we should add.
  • It can create images to preview how our painting would look using just those colours
  • … and provide maps to show where we should be using each colour in relation to the sketch.
  • It will compare imported photos of our work-in-progress to our reference and suggest changes.

…and more such as image filters and support for mosaics, tapestries and embroidery.

Once we are comfortable with various tasks, say we'd rather draw our own sketch or choose our own colours, then we can do those bits on our own. With each new painting we can take on more of the responsibilities ourselves until we don't need it anymore.

For if you cannot paint what you see you will find your self handicapped in trying to paint what you imagine. Harold Speed

The Artist's Helper helps artists with the craft of their painting but it doesn't help painters with their art.

In the same way violinist plays his scales, so as to acquire the capacity of producing pure tones on his instrument and training is ear to appreciate accurately the intervals between the different notes, so the painter trains his eye to perceive accurately the appearances on his retina, and trains his hand to express accurately these perceptions. Not that playing scales is music, or training the eye is art; but because without this training we have no control of the means by which artistic things are done. Harold Speed

Why is painting difficult in the first place? meh, skip this bit - come back later


There are two approaches to drawing (at least):

Constructive drawing
where the the artist builds a scene from component parts.
Replicative drawing
where a visible scene or a reference image is captured and reproduced based on how it actually looks. The component parts and mechanics of the scene can be disregarded in favour of the final view.

Constructive drawing

To draw well with the constructive approach the artist must know a lot about the objects in the scene. They need to know the relative sizes and proportions of the objects and their component parts. They need to be able to mentally manipulate the parts and imagine how they will look from a particular orientation, where the lighting is coming from, how it will interact with each part and what shadows will be cast. They may need to understand perspective and foreshortening, loss of contrast and definition with increased distance and more.

Replicative drawing

Hetch Hetchy

Forget about the drawing the concept of the thing and draw the appearance of the thing.

Using the replicative approach the artist does not need to know anything about the objects in the scene other than their relative locations and colours. Indeed it can be desirable for an artist to deliberately repress anything they know about the objects contained in the view in order not to fall into any traps of the constructive approach.

Draw what you see, not what you know to be there.
Think of colour first, subject last. Everything begins as an abstraction of colour. Sergei Bongart

The replicative approach requires the scene be visible to the artist (or at least have been visible if they have a great memory). The artist must study a the scene or reference in detail but they do not need to understand it.

Drawings can be a mix of the two approaches. Sometimes without the artist realising. This can be a good thing but it can also lead to disconnections. A modelled object, perhaps with incongruous, contradictory lighting, might be included in a scene and look like something cut out from a different picture.

Colour judgement

A and B are the same colour #787878
©1995, Edward H. Adelson

Judging the colours in a scene is extremely difficult. There are so many optical illusions which can fool us into thinking that the same colour, repeated in different situations, can look wildly different in each. The lighting plays as great a part on the perceived colour of an object as its underlying local colour. If not more so.

Even discounting optical illusions it's still hard to judge whether two colours match. Getting them a little wrong doesn't seem such a big deal individually, case by case, but can make the final image look odd for reasons that can't always be easily fathomed.

Colour mixing

Once we have determined what colour we want we still have the problem of mixing it from our available palette.

When I started all this I had absolutely no idea what I was doing. This problem was the main driver for me when I started writing the helper program.

Paint technicalities

It turns out that it's not so difficult once we get to know which experts to trust and which to ignore.

Although it is perfectly true there is no black in the solar spectrum visual phenomena are not entirely made up of light. There is the negation of light -- darkness. There are places where the light does not fall, although there is probably no shadow so deep but some light is not reflected. These omissions on the palate Rob most of the impressionist pictures of much of the dignity associated with really fine colouring. Harold Speed

Paint application

Again, not actually all that difficult. Once we know the right colours and the right places we can just splodge them in.

Some paints dry faster than others which can put us up against the clock. We need to plan our workflows to allow us to cope. Choosing the right brush sizes makes a fair difference.

But these are all minor hurdles that are easily cleared with a liffle forethought.

Real paint, real things and a strategy origins, skip this bit too

paint brushes

I needed a break from working with computers so I decided to take up painting.

I wanted to do real paintings with real paints.

I was only interested in learning representational painting.

I soon found that creating a real representational painting requires a daunting host of skills.

Minor rant about tutorials feel free to ignore

Looking for help, I watched a lot of painting tutorials on YouTube. Some good, some not. They seemed to be made by people who either trotted out rules without much insight:

Get the shadow colour by adding its complementary colour.
You mustn't use black.
To get a good, vivid octarine1 you should always mix raw hooloovoo2 with a little burnt amaklor-kalish3.

Some of these guys are trying too hard to look good and come across as an expert. They disguise their mistakes and hide the areas with which they struggle even though those would be the most interesting and useful bits.

Or worse, people with tremendous natural talent who just knew exactly what to do but who could not see that there was magic in there that needed to be explained:

What we want here is a nice warm green, *splat*slap*daub*, just like that.
There are no rules. Paint whatever you want, however you want.
drawing of an owl
draw the rest of the owl

That's a bit: draw the rest of the owl.

I will do my best not to fall into these traps.

[1] octarine
a fluorescent greenish-yellow purple from the Discworld books
[2] hooloovoo
a hyper-intelligent shade of the colour of blue from The Hitchhiker's Guide to the Galaxy
[3] amaklor-kalish
an ultra-violet that can be seen by Klingons in Star Trek.

So, I decided to cheat. I would automate as many of the requirements as possible. I could then pick from them and focus on a single skill, one at a time.

This also meant that my initial attempts at painting produced decent outcomes which encouraged me to keep moving forward.

I needed to come up with a learning strategy because that is the kind of geek I am.

The first key to good drawing and painting is good observation.

We cannot depict a golden retriever if we have never seen one before another minor rant, please ignore me

Even if we have seen lots of them can we really remember their proportions and colours well enough? Do we know what separates them from other dogs?

Even when we have an individual in mind and we know her well but we are not currently looking at her, do we really know her distinctive characteristics by heart?

Even if we can remember her proportions, colours and characteristics, can we envisage how she would look mid leap? The enthusiasm in her eyes? Can we envisage her lit by a low early morning sun?

Does it matter?

So that lead me to the first part of the strategy:

*** Always paint from some sort of reference. ***

So, key number 2:

*** Paint from digital reference images. ***

This immediately helps to solve many difficulties in one go.

Ok, but why digital reference images?

Colour mixing

I found colour mixing difficult. So I wrote a program to help me understand colour and work out paint recipes.

We can select a target colour from the reference image. Then we need to tell the program what paint colours we have available as mixing ingredients. One way to do this is to load a photograph of samples spread out on a palette.

The program displays our target colour and our ingredient paints in an interactive colour-space-widget. This shows us what ingredients to combine to make a trial mixture. Mixing lines are drawn to show what the various ratios of ingredient paints will give. We can photograph the trial mixes and load them into the application to find how close we are and what to add next to get closer still.

We can photograph and load the trial mixes to find how close we are and what to add to get closer still.

A sketch

We need a sketch as a scaffold from which we can hang our paint.

Picking out suitable lines to trace is not easy in some photos. Scaling and printing it to the right size can be tricky too.


Lenna sketch

If we enter the size of our canvas our helper will scale it and print it over multiple sheets. Each sheet will have overlaps at the edges and markers to help line them up accurately.

Colour breakdown

Seeing the colours in a scene is more difficult than it sounds (see colour judgement above). Judging the relative values of different colours, that is their lightness or darkness can be even harder.

We can decide which colours we want to use by manually picking them from the subject, having the helper automatically choose some for us or loading them from a photo of the paints or colours that we have available (useful when we can't so easily modify our available colours such as for mosaics, embroidery etc.).

Once we have a trial set of colours it would be nice to see what a picture would look like using only these. We can add more colours to refine the picture further or disable some to simplify it.


As we now have a pop-art style block-in of colours it might be handy to have a outline map/cartoon of them.

The outlines get very complex but pre-filtering the subject image can remove a lot of noise.

The little blue rectangles show where I have sampled colours from the subject image.


Whilst I was writing filters for smoothing and simplifying I added some others for brightness, saturation, contrast, sharpness, hallucinogens etc.

Although it it possible to over-do these things…


Once the painting is in progress it is hard to see where we may be going wrong. What needs more work and what we should leave well alone? So I wrote something to compare photos of our work-in-progress to the reference image.

Several metrics are available and can be displayed in different ways.

Original photo: Oakley

The painting in progress
comparison DeltaE
the colour shown indicates the colour distance between the subject image and a photo of the canvas.
comparison Baseline-85
show areas whose colour difference is over a value specified with a slider control
comparison Luma
highlight the differences in colour values.
comparison Saturation
highlight the differences in saturation
comparison Hue
it looks bad but large differences don't matter at low saturations.
Not a very useful measure but it is included for completeness. Somebody might need it one day.
comparison Hue and Saturation
hue differences scaled by the saturation
Much more useful. We are looking pretty good here.
comparison Difference
the same as the difference blending mode in GIMP.
May not be very useful?
comparison Glaze
the colour of the glaze that would get the canvas closer to the subject.
Colour difference extended and exaggerated by a slider value. Pay particular attention to colours that aren't simply an exaggerated version of the subject, eg. the blue behind the nose.

Who is the Artist's Helper aimed at?

It's aimed mostly at me, …but it has value for:

The absolute beginner who wants to paint but doesn't know where to start

Learn how to paint with the assurance of a satisfactory outcome for your endeavours.

With this software there is no need for dozens of time wasting, trial and error attempts which will probably be immediately discarded before you create your first worthwhile painting.

Those first embarrassing efforts, floundering in the dark, can dent confidence and derail enthusiasm.

Practice versus guidance

We are often told that the only way to learn to paint is to practice, practice, practice. But practice does not make perfect. Practice makes permanent. If we practice at doing it wrong we will get very good at doing it wrong. Habituated. We need guidance.

Guidance from the Artist's Helper can save us years of grinding. It cannot make us into artists but it can help us become good painters.

However, it will only help us learn to create works from reference images.

We will soon be able to paint a decent picture without needing any of that old natural born talent rubbish.

The more experienced painter who wishes to understand the nature of colour

The colour visualisation tool can help achieve an understanding of the dimensions of colour. It can answer questions like why can a mix of blue and yellow look green? or why do mixtures of complementary colours produce greys?.

colour-space: blue plus yellow
The scholar who wishes to study the palettes of existing paintings

Drag an image of a painting into the colour chart to see the colours used in a three dimensional space which we can rotate, tilt and zoom.

Some paintings have fluorescent colours which just cannot be achieved with standard paints.

colour-space Johannes Vermeer Johannes Vermeer - Girl with a Pearl Earring - 1665 colour-space Francoise Nielly Francoise Nielly - UNTILTED 594 - 2011

The tutorial The very quiet call to action

So, now you know what it is, you should read the tutorial.

The Artist's Helper's helpers

I'd like to develop this into a proper product, maybe via a kickstarter campaign. The prototype is up-and-running but I need some help with testing it and especially help to sanitise and flesh out the tutorial.

I am looking for two or three pioneer guinea pigs who want to learn how to paint and who are amenable to help me test the software.

I also want pictures of *your* paintings to be included in the tutorials and galleries.

If you're interested email me: Bob.

This sounds interesting. It's like a way to play without having pressure to necessarily create something complete from nothing, which, when learning a new medium, is sometimes the hardest part. u/CinderQuill22 via r/learnart
(about tracing but applicable to the whole thing)

Application changes

If anyone has anything they'd like added just let me know.

Here are some changes I'm contemplating that I'd like some opinions on

Layer name changes. Some are confusing. It's difficult to write about paints in the tutorial when it might mean a layer, some physical paints, some palette entries. Also some layers have the same initial so the hotkeys are odd.

  • paints -> preview or rendering
  • subject -> filtered
  • original -> unfiltered or reference (or possibly subject -> reference)
  • canvas -> work or work-in-progress

Remove the Load named colours and Load cube palette… sub-menus and supply some palette properties files for them instead.

more to be added...

Website changes

I'm clearly neither a copywriter nor a graphic designer so if anyone has specific changes to the website they'd like to see then I'm all ears.


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