CAVstudio: a visual tool for training AIs
on subjective concepts

Using Concept Activation Vectors to power
more nuanced, visual search.

Google AI (Mural x PAIR x Brain): 10 weeks

Material exploration with Concept Activation Vectors, interaction
design-led R&D, advanced prototyping, on-device ML.
AI so far: One size fits all
AI so far: One size fits all

Machine Learning models are expensive to train in data, time and cost. As such, they’re mostly produced in small quantities by big tech companies, which creates homogenised models with a unified view of the world.

They’re great for objective tasks like recognition, but fail to tackle subjectivity, where visual interpretation is shaped by culture and community, and is personal to the individual.

1000s of images
100s of human hrs
$$$ cost
AI tomorrow: Grass-roots personalisation
AI tomorrow: Grass-roots personalisation

For AI to play a deeper role in our lives, we will require new, shared forms of Human:AI expression.

With only a handful of images, we can use a new technology called CAVs (Concept Activation Vectors) to quickly skew a model’s focus in a particular direction - allowing anyone to personalise an AI model to see things in a particular, nuanced way.

10-30 images
in seconds
virtually zero cost

To test this idea of visually subjective AI, we went as far
from objectivity as we could - the visual arts.

CAV-powered AI models have the ability to detect visually subjective qualities present within a sequence of images. We call these concepts - for instance ‘atmospheric’.

But what does it mean for an artist to train an AI on an particular way of seeing?

And what happens when others take their concept and use it to surface new curations and compositions as a source of inspiration, serendipity or simply to ‘try on’?
CAVstudio enables anyone to express visually subjective concepts to an AI, through a shared medium: moodboards.

CAVstudio - train an AI to find nuance in imagery

• Drag and drop moodboard interface
• Powered by CAVs with only 10-30 images
• Makes training subjective AI’s accessible to anyone
• Inspires new discoveries and alternate perspectives

CAVstudio - train an AI to find nuance in imagery

• Drag and drop moodboard interface
• Powered by CAVs with only 10-30 images
• Makes training subjective AI’s accessible to anyone
• Inspires new discoveries and alternate perspectives
1/6
Learn visual concept

Express a way of seeing as a visually coherent moodboard, then see how the AI model interprets your concept.

CAVstudio lets you choose from different model layers, depending on the concept you’re trying to express. Some layers are more sensitive to colour and texture, others are better for shapes and compositions.

2/6
Focussing

Refine your concept by upweighting images that best express your way of seeing. Downvote results where the AI isn’t quite getting it. Iterate.

Upweighted images appear larger in the moodboard, reflecting their ‘weight’ of bias being applied in the CAV.

3/6
Composition

Search results are surfaced in seconds. Preview shows the images that best match the concept, curated by the model. AI Crop goes a step further letting the model point to the optimum composition in the chosen image.

Image curation is based on CAVscore. By cropping each image in multiple ways, and then scoring each crop against the CAV, we can pull in to focus where the concept is most salient.

4/6
Inspectability

See the results through the eyes of the AI with Inspect mode’s heatmap and focus tools. This helps you understand what visual qualities the AI is drawn to, to help you get on the same wavelength

Heatmap uses the perceptually uniform 'magma' to represent CAVscore per pixel. Focus represents the most optimum crop based on CAVscore.

5/6
Search different image sets

CAVstudio was built with some rudamentary search sets of images that we assembled for testing. But you’re not restricted by this. Anyone can upload their own search set, be it from their own image bank or public access repositories.

Everyday examples by Nord Projects was produced using ambiently captured imagery from London and the UK. It includes urban, rural, environments, objects and graphics, but excludes other contexts or cultures.

6/6
Name your concept

Last but not least, decide how best to name your concept. Each concept is saved to your library and can be shared with others using the URL, or by downloading the .CAV file itself.

Because concepts are subjective, we avoid the explictness of a #. Instead we use the tilde ~ to reflect their inherent approximation and interpretability.

These concepts form the beginnings of an indexable cultural ecosystem.


And by using moodboards instead of labels, CAVstudio lets anyone working with visual imagery train and collaborate with ML systems, irrespective of language or technical expertise.

In practice

To help test the limits of visual expression in AI, we collaborated with three local artists, each using CAVstudio to produce a distinct concept.

Alex Etchells

Street photographer

Tom Hatton

Fine artist

Rachel Maggart

Artist and Curator

Their outcomes worked surprisingly well. Unlike a typical Google or Pinterest search, the images returned by the CAV are diverse in subject matter and composition, but all speak to the same visually subjective qualities common across the mood board training images.

To test the impact of searching with CAVs, artists used each others concepts to explore their own existing photo libraries.

“The ~SightUnseen AI crop has shown me a view of my own photography that I wouldn’t normally be able to see!
Alex
“Using Alex’s concept on my own photos really let me see the world through a different lens. It let’s you escape the ordinary, initiating more creativity.”
Rachel

The CAV system

CAVstudio is a browser-based tool that uses a Python backend to generate a CAV from your training images. It then sorts a set of images to play back what it saw. The CAV can be downloaded to be used in other projects with CAVlib.

How do CAVs work?

• Give the ML model a handful of images and it analyses them at a pixel level, spotting patterns and relationships.

• CAVs learn to find an underlying visual thread, present across a set of images

• This is described by the ML model in the form of a mathematical ‘vector’ or direction in high dimensional space (ML speak for a machine’s imagination). We call this concept a CAV.

• ML models can then use this new found understanding of subjective concepts like ~Graphic to search image sets in order to surface meaningfully different results.

Give the ML model a handful of images and it analyses them at a pixel level, spotting patterns and relationships. CAVs learn to find an underlying visual thread, present across a set of images

This is described by the ML model in the form of a mathematical ‘vector’ or direction in high dimensional space (ML speak for a machine’s imagination). We call this concept a CAV.

ML models can then use this new found understanding of subjective concepts like ~Graphic to search image sets in order to surface meaningfully different results.

How do CAVs see?

‘Concept collages’ is a technique we developed as a way for the CAV to visually express what it thinks is the essence of a concept.

Here, moodboard training images are segmented based on the saliency of the CAV/concept in that image. The highest scoring segments are then overlaid on top of each other, creating a collage effect.

Concept collages are an incredibly rich form of visual vocabulary, providing a flavour of a concept. We imagine these being useful when creating a concept, or deciding which concept to use.

CAVstudio is an open source project. In time we hope to release a public-facing version, but for now you’ll need to download the code from GitHub and run the tool locally.


More on that here

CAVlib

CAVlib is a Python Library that exposes the underlying tech powering CAVstudio. It lets anyone take .cav files and use them in their own websites, apps and prototypes.

In only a few lines of code, CAVlib unlocks the power of meaningful visual interpretation and search for a host of potential new applications. Visit the GitHub to learn more and try it yourself.

What next?

Try CAV Camera yourself

CAV Camera is on the Play Store. It’s designed for Pixel 4, 5 and 6, but works on other Android devices too.

Check out CAVstudio

CAVstudio is where you can make your own visually subjective concepts, that can be imported into CAV Camera.

Build with CAVlib

CAVlib makes it easy for people to utilise the expressive power of CAVs in their own projects and products.

And finally thanks to:

Been Kim and Emily Reif from Google AI who developed the TCAV technology and worked with us to humanise it.

Alex Etchells, Rachel Maggart and Tom Hatton for their artistic experimentation with CAVs.

Eva Kozanecka, Alison Lentz and Alice Moloney from Mural who commissioned the project and guided it creatively.


Not to mention Matt Jones, Martin Wattenberg and Fernanda Vegas who helped us uncover the value of CAVs.