Cross-domain Microscopy Cell Counting by Disentangled Transfer Learning

Microscopy cell images of biological experiments on different tissues/organs/imaging conditions usually contain cells with various shapes and appearances on different image backgrounds, making a cell counting model trained in a source domain hard to be transferred to a new target domain. Thus, costly manual annotation is required to train deep learning-based cell counting models across different domains. Instead, we propose a cross-domain cell counting approach with only a little human annotation effort. First, we design a cell counting network that can disentangle domain-specific knowledge and domain-agnostic knowledge in cell images, which are related to the generation of domain style images and cell density maps, respectively. Secondly, we propose an image synthesis method capable of synthesizing a large number of images based on a few annotated ones. Finally, we use a public dataset of synthetic cells, which has no annotation cost at all as the source domain to train our cell counting network; then, only the domain-agnostic knowledge in the trained model is transferred to a new target domain of real cell images, by progressively fine-tuning the trained model using synthesized target-domain images and a few annotated ones. Evaluated on two public target datasets of real cell images, our cross-domain cell counting approach that only needs annotation on a few images in a new target domain achieves good performance, compared to state-of-the-art methods that rely on fully annotated training images in the target domain.