painty

Library containing several algorithms for:

• Image processing.
• Non photorealistic rendering: painterly rendering, image abstraction and stylization.
• Paint rendering and realistic mixing.
• Color conversions.
• ... and more to come.

Paint Renderer

• Implementation of the Kubelka-Munk equations.
• 2d imprint brush (3d on the roadmap).
• 2d texture brush.
• Realistic paint mixing.

Simple paint program

Image Stylization and Non Photorealistic Rendering

• Image convolution wrapper for OpenCV.
• Flow fields of images.
• Edge detectors.
• Superpixel segmentation.

Implementation of the image abstraction filter proposed by Kyprianidis, et al.

Input image	Filtered

Color Palette Extraction from RGB Images

Extract color palettes from images based on base pigments. The solver esimates absoprtion and scattering coefficients of each paint as a mixture from the base pigments.

Primary Magenta	Carmine Red	Cadmium Red Medium	Raw Umber	Cadmium Orange Hue	Cadmium Yellow Hue	Primary Yellow	Leaf Green	Phthalo Green	Cobalt Blue Tone Deep	Ultramarine Blue	Lilac	Lamp Black	Titanium White
0	0	0	0	0	0	0	0.0947	0.262	0.0903	0.215	0	0.337	0
0	0	0	0	0	0	0	0	0	0	0	0.019	0	0.981
0	0	0	0	0	0.00757	0	0.192	0.59	0.139	0.0424	0	0	0.0292
0	0	0.0854	0	0.171	0.0692	0.674	0	0	0	0	0	0	0
0.146	0.211	0.437	0	0.206	0	0	0	0	0	0	0	0	0
0	0	0	0.0063	0	0	0	0.0369	0.212	0.216	0.259	0.0625	0.206	0

more details

References

Implementation based on the following papers:

• Bill Baxter, Vincent Scheib, Ming C. Lin, and Dinesh Manocha. 2001. DAB: interactive haptic painting with 3D virtual brushes. In Proceedings of the 28th annual conference on Computer graphics and interactive techniques (SIGGRAPH ’01). Association for Computing Machinery, New York, NY, USA, 461–468. DOI:https://doi.org/10.1145/383259.383313
• Nelson Chu, William Baxter, Li-Yi Wei, and Naga Govindaraju. 2010. Detail-preserving paint modeling for 3D brushes. In Proceedings of the 8th International Symposium on Non-Photorealistic Animation and Rendering (NPAR ’10). Association for Computing Machinery, New York, NY, USA, 27–34. DOI:https://doi.org/10.1145/1809939.1809943
• Lindemeier, T., Gülzow, J. M., and Deussen, O. Painterly rendering using limited paint color palettes. InVision, Modeling & Visualization(2018), F. Beck, C. Dachsbacher, andF. Sadlo, Eds., The Eurographics Association.
• Lindemeier, T., Metzner, J., Pollak, L., and Deussen, O. Hardware-based non-photorealistic rendering using a painting robot. Computer Graphics Forum 34, 2 (2015),311–323
• Lindemeier, T., Spicker, M., and Deussen, O. Artistic composition for painterly rendering. InVision, Modeling & Visualization(2016), M. Hullin, M. Stamminger, andT. Weinkauf, Eds., The Eurographics Association
• Kyprianidis, J. E., and Kang, H. Image and video abstraction by coherence-enhancing filtering. Computer Graphics Forum 30, 2 (Apr. 2011), 593–602