Egocentric visual augmentation by wearable wide projector

HeadLight has a fish-eye conversion lens on the projector which enables much wider projection image. However, the conversion lens produces strong distortion in the projected image with pincushion shape. The Headlight system compensates this distortion based on a fisheye model distortion. Therefore, Headlight enables wide angle visual projection from the point of view of user up to 131 degree in diagonal angle, minimum approx. 105 deg. horizontal and 55 deg. vertical, which covers a large field of view of human.

In Headlight system, the three-dimensional virtual space that is consistent with the physical environment is rendered with a virtual camera based on tracking information of the device. By processing inverse correction of the lens distortion and projecting the rendered image from the projector, Headlight performs consistent visual augmentation in the real world.


​​​In addition, since the Headlight system can generate image synchronously with one’s head movement, motion parallax can be generated by the change of the projected image
Due to the perception of depth caused by this moving parallax, the user feels that a virtual object exists in front of or behind the surface regardless of the physical arrangement of the actual projection plane.


I envision that physical phenomena that human could not perceive will be perceived through visual augmentation. Our lives and the environment are designed based on human perceptual abilities. However, at the same time, in this real world there are a wide variety of species with different sensory abilities. If human beings were able to have their perceptual abilities using technology, I believe that we human will perceive the real world from a new perspective.​

実世界視覚拡張のための装着型Mixed Reality装置。広角変換レンズ、小型レーザープロジェクタ、ヘッドフォン、ヘッドトラッキング装置等で構成される。リアルタイム映像補正により、ユーザの視点から対角線上で最大131度の広角視覚投影を実現し、目を覆うことなく、人間の大部分の視野をカバーする映像投影を可能にする。さらに、ヘッドトラッキングと3次元空間情報によるプロジェクションマッピングによって、装着者が向いている方向へ投影された映像はその物理環境に存在しているように見える。


Collaboration with Visual System – 比嘉 了 (Satoru Higa) /
Sound Design – Shotaro Hirata /
Hardware design – 小西 哲哉 (Tetsuya Konishi)

Shunichi Kasahara. 2018. Headlight: egocentric visual augmentation by wearable wide projector. In ACM SIGGRAPH 2018 Emerging Technologies(SIGGRAPH ’18). ACM, New York, NY, USA, Article 10, 2 pages. DOI:


Posted by:shunichikasahara

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