“See-through” data sets for nonlinear source separation (2005)
When we scan or photograph a paper document, the image printed on the back page often shows through, due to partial transparency of the paper. The data sets given here correspond to a severe case of this problem, in which the paper that was used was “onion skin” (for readers whose native language is not English, onion skin paper is the semi-transparent paper that is often used in professional drawing). The strong transparency of the onion skin paper originates a strong mixture of the images from the front and back pages. This mixture is significantly nonlinear. Since two different mixtures can be obtained by scanning both sides of the paper, these mixtures are good candidates for nonlinear source separation. The mixtures are close to singular in the lighter parts of the images.
Sample images (1997)
This is the image data used in our ICA experiments on natural images. The images are in TIFF format for easy reading into MATLAB using the ‘imread’ command. They can also be viewed for example with the ‘xv’ program in unix. The photographs are copyrighted: © Janne Sinkkonen 1994, 1995, 1996, 1997. Copying is permitted only for noncommercial use. Thanks are due to Janne Sinkkonen for taking the images. They are originally in color and of much higher resolution. You can take a tour of his work at his homepage.