  Partitioning an image into superpixels based on the similarity of pixels with
respect to features such as colour or spatial location can significantly reduce
data complexity and improve subsequent image processing tasks. Initial
algorithms for unsupervised superpixel generation solely relied on local cues
without prioritizing significant edges over arbitrary ones. On the other hand,
more recent methods based on unsupervised deep learning either fail to properly
address the trade-off between superpixel edge adherence and compactness or lack
control over the generated number of superpixels. By using random images with
strong spatial correlation as input, \ie, blurred noise images, in a
non-convolutional image decoder we can reduce the expected number of contrasts
and enforce smooth, connected edges in the reconstructed image. We generate
edge-sparse pixel embeddings by encoding additional spatial information into
the piece-wise smooth activation maps from the decoder's last hidden layer and
use a standard clustering algorithm to extract high quality superpixels. Our
proposed method reaches state-of-the-art performance on the BSDS500,
PASCAL-Context and a microscopy dataset.
