Hitachi Ltd developed a technology of clearly showing video projected by a projector even in bright light coming from outside.
The technology processes full HD-equivalent video at a rate of 60fps in real time. It was realized as a 17 x 17mm chip. And Hitachi Maxell Ltd will release a projector equipped with the chip in April 2014.
A projector projects video on a screen, which becomes bright in a place where light comes from outside, blurring the entire video. There are some conventional methods to improve the visibility of projected video such as contrast correction and color management. However, those methods apply the same correction to the entire screen, causing some side effects such as blurring clear part of the video and making it difficult to realize a significant correction effect.
This time, Hitachi developed a video correction algorithm using the "Retinex" theory, which was established based on the visual properties of humans. The algorithm analyzes the brightness, fineness, etc of each area of video projected on a screen. Then, it separates multiple optic elements, strengthens them in accordance with their brightness, fineness, color tone, etc and synthesizes an emphasized portion of video. As a result, it becomes possible to drastically improve visibility while preventing side effects, the company said.
For example, processed video has improved gloss and shading, and the outlines of objects in the video become more vivid. Also, the new technology improves the visibility of dark areas without affecting bright areas and enables to vividly reproduce color information contained in original video without losing it.