  Training supervised deep neural networks that perform defect detection and
segmentation requires large-scale fully-annotated datasets, which can be hard
or even impossible to obtain in industrial environments. Generative AI offers
opportunities to enlarge small industrial datasets artificially, thus enabling
the usage of state-of-the-art supervised approaches in the industry.
Unfortunately, also good generative models need a lot of data to train, while
industrial datasets are often tiny. Here, we propose a new approach for reusing
general-purpose pre-trained generative models on industrial data, ultimately
allowing the generation of self-labelled defective images. First, we let the
model learn the new concept, entailing the novel data distribution. Then, we
force it to learn to condition the generative process, producing industrial
images that satisfy well-defined topological characteristics and show defects
with a given geometry and location. To highlight the advantage of our approach,
we use the synthetic dataset to optimise a crack segmentor for a real
industrial use case. When the available data is small, we observe considerable
performance increase under several metrics, showing the method's potential in
production environments.
