Paste, Inpaint and Harmonize via Denoising: Subject-Driven Image Editing
  with Pre-Trained Diffusion Model
Xin Zhang Jiaxian Guo Paul Yoo Yutaka Matsuo Yusuke Iwasawa
Text-to-image generative models have attracted rising attention for flexible
image editing via user-specified descriptions. However, text descriptions alone
are not enough to elaborate the details of subjects, often compromising the
subjects' identity or requiring additional per-subject fine-tuning. We
introduce a new framework called \textit{Paste, Inpaint and Harmonize via
Denoising} (PhD), which leverages an exemplar image in addition to text
descriptions to specify user intentions. In the pasting step, an off-the-shelf
segmentation model is employed to identify a user-specified subject within an
exemplar image which is subsequently inserted into a background image to serve
as an initialization capturing both scene context and subject identity in one.
To guarantee the visual coherence of the generated or edited image, we
introduce an inpainting and harmonizing module to guide the pre-trained
diffusion model to seamlessly blend the inserted subject into the scene
naturally. As we keep the pre-trained diffusion model frozen, we preserve its
strong image synthesis ability and text-driven ability, thus achieving
high-quality results and flexible editing with diverse texts. In our
experiments, we apply PhD to both subject-driven image editing tasks and
explore text-driven scene generation given a reference subject. Both
quantitative and qualitative comparisons with baseline methods demonstrate that
our approach achieves state-of-the-art performance in both tasks. More
qualitative results can be found at
\url{https://sites.google.com/view/phd-demo-page}.