Browse Prior Art Database

Compensation of geometric distortion in projectors

IP.com Disclosure Number: IPCOM000179726D
Original Publication Date: 2009-Feb-24
Included in the Prior Art Database: 2009-Feb-24
Document File: 1 page(s) / 165K

Publishing Venue

IBM

Abstract

portable projectors connected to personal computers are commonly used for presentations etc. and very often the projection occurs in a surface that presents some "defects". Such defects for example may include bumps, dents, non-flat areas and so on. Moreover, there is distortion caused by the fact that the projector beam is not perpendicular to the target surface, but almost always comes from an angle, thus introducing another kind of distortion (trapezoid).

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Compensation of geometric distortion in projectors

Disclosed is a device to manipulate the image produced by the personal computer so that when it is distorted by the projector, the actual result is a correct image. This can be done with a software application that runs on the personal computer itself.

     In these picturee there is a simple example of what the software can do, but of course it is not limited to such a simple case.

Picture 1. PC to Projector (perspective distortion)

Picture 2. The image is pre-distorted so that when the distortion induced by perspective occurs, the resulting image is correct.

     There are several advantages to this approach: it can potentially cover all kinds of distortion, you don't have to fiddle with hardware settings of the projector, you can save and reload custom setups, it's cheap and so on.

There is also a price to pay though, as compensating for some kind of distortions will require some loss of image resolution, i.e. you set the PC to work in 1024x768 resolution and the resulting image will have lower quality, say 800x600 but that in fact depends on the kind of transformation applied.

1

[This page contains 2 pictures or other non-text objects]