HP Innovation Journal Issue 03: Summer 2016 | Page 23

UNIVERSITY OUTREACH A colorful collaboration Purdue University and HP: Decades of imaging innovation In our previous issue we touched on the long-standing research collaboration HP has with Purdue University. This 25-year collaboration has paved the way for amazing innovation in imaging, and is now setting the stage for advancements in ambient computing technology for home and office applications. T he collaboration between Purdue and HP started in 1992. While Qian Lin was an intern at HP Labs during her PhD program at Stanford University, she invited Professor Jan Allebach and his colleague Professor Charles Bouman to give a presenta- tion at HP Labs. Professor Allebach was Qian’s former advisor at Purdue University when she was working on her Master’s degree in HP Color LaserJet Pro Electrical Engineering. Professors Allebach and Bouman were well-known researchers in the area of electronic imaging and Qian thought they would provide valuable insights to the HP team. This was the start of a collab- oration between Purdue University and HP that included HP Labs, and printer divisions in Boise, ID, Vancouver, WA, Israel (Indigo and Scitex), and Barcelona, Spain, that has continued through present day. Professor Allebach himself spent six summers as a Visiting Researcher at HP Labs, and later did a sabbatical there. One result of this strong engagement with HP was Professor Allebach’s contribution to the development of HP’s Color Smooth Dither technology. Dithering means creating the illusion of colors and shades by The image on the left uses the same dither matrix for all colors. The image on the right uses Color Smooth Dither which distributes cyan, magenta, and yellow dots varying the dots in an stochastically. This results in a less grainy appearance. image. In printing, dith- ering is usually called halftoning, and shades this work. Sixteen faculty members and over of gray are called halftones. Halftoning is 60 graduate students from four different a key component in the printing pipeline departments at Purdue have participated in that directly affects the print this research. image quality. While work- Acknowledging the contributions from ing on a research project in Purdue professors and researchers, HP en- digital holography, Professor dowed the Hewlett-Packard Professorship in Allebach developed an al- 2006, which is presently held by Professor gorithm called Direct Binary Jan Allebach. The Purdue and HP collabora- Search to design holograms. tion continues to grow in the quest to solve During one of his summers at some of the complex problems involving HP Labs, he collaborated with multi-disciplinary research. As an example, Qian, a renowned researcher a new research project explores using deep in halftone algorithms for HP learning to recognize objects in images in real printers. Applying Jan’s direct time for ambient computing applications.   binary search ideas to those algorithms led them to the design of halftone dither matrices called “Color Smooth Dither” that were shipped in HP Inkjet and large format printers. Many other technologies developed in the collab- oration between HP and Purdue can be found in a wide range HP’s printer products. Over two dozen patent applications have been filed by HP to protect HP PageWide web press Issue 3 · Summer 2016 · Innovation Journal 23