DAFNE (Digital Anastylosis of Frescoes challeNgE) dataset

This dataset was originally created for DAFNE, an international challenge concerned with collecting outstanding contributions to the field of Anastylosis, whose submissions closed in July 2019. The goal was to develop tools enabling digital reconstruction of heavily damaged frescoes, supporting their restoration through the solution of the ‘puzzles’ formed by the remaining fragments, often mixed with spurious elements.
The winners of the challenge presented their results and have been awarded during the 20^th International Conference on Image Analysis and Processing (ICIAP 2019) held in Trento, Italy, from 9th to 13th September 2019. The proposed algorithms have been published, after a peer review, in a dedicated Virtual Special Issue of Pattern Recognition Letters on Digital Anastylosis of Frescoes challeNgE (DAFNE) (Elsevier journal).

The dataset is now publicly available, but its use is restricted to research, education and non-commercial purposes.

Dataset characteristics

The dataset has been built applying simulated fragmentation to famous frescoes' images. For each fresco you will find: an image of the original fresco and 18 folders, each one containing:

• a set of fragments — randomly generated — to be reassembled, eventually mixed with spurious elements (PNG files in the folder frag_eroded — each file is a fragment);
• a list of the co-ordinates of the exact location and orientation of the fragments correctly placed in the reconstructed image (fragments.txt);
• a list of the spurious fragments (fragments_s.txt);
• the parameters used for the simulated fresco fragmentation (parameters.txt);
• the solution consisting in the image of the original fresco with a grey background, with overlapping coloured fragments (rebuilt_image.png).

Example of plane tessellation and ground truth (original image in grey background, with overlapping coloured fragments) for "Cesare Nebbia - The Plague of Milan, 1604"

 

The dataset was designed to be realistic, natural and challenging for cultural heritage domains, in terms of image resolution, diversity in scenes, and pictorial assets. The fragments were obtained, from each fresco, through a random plane tessellation with suitable statistics (uniform or with a few clusters as shown in the DAFNE Annex), with an erosion process applied to each fragment.
The data distinguishing characteristics are quantized by the following five basic parameters:

• A: number of fragments
• B: type of random distribution
• C: percentage of missing fragments
• D: percentage of spurious fragments
• E: average ratio between the fragment area after the erosion and the original area in the fresco plane tessellation.

The dataset was originally divided in two parts: DB1, provided with all the solutions, to be used as training set for the development phase; and DB2, with no solutions, to be used for the testing challenge phase. Now, the solutions for DB2 (i.e., the exact coordinates and orientation of each fragments, the list of spurious ones, and the reconstructed image) are also provided.

Dataset download

For download, please visit the DAFNE dataset download page. For additional information, send an email to daf-challenge-group@unipv.it. You will receive a reply as soon as possible.

Javastylosis

Javastylosis is a computer-assisted tool developed to support restorers for reassembling 2D images of damaged frescoes. The user can manually move the virtual fragments, group, rotate, match, and eventually discard spurious elements, to reassemble a digital solution of the ‘puzzles’ made by the images of the fractured fragments. The output of the application is a digital solution that provides a table of coordinates (a CSV file) useful to correctly reposition the real fragments.
> download <
A complete description of the tool is in "Javastylosis: a tool for computer-assisted chromatic and semantics based anastylosis of frescoes"

Copyright

The images are provided for non-profit purposes and their use is restricted to research, education and non-commercial objectives. Despite every effort to contact copyright-holders, the organizers should be contacted as regards any omissions or errors.