[Paper] Radiometric Compensation Using Color-Mixing Matrix Reformed from Light Transport Matrix

Abstract

We propose a practical method that realizes radiometric compensation based on direct and indirect light transports so that uncalibrated projector-camera systems can create desired image displays on 3D objects. By introducing compressed sensing, we efficiently construct the light transport matrix that includes direct/indirect light transports reflected from unknown 3D objects. Assuming that each camera pixel receives a linear summation of direct and indirect reflection lights via the color-mixing matrices, which are reformed by reference to the light transports, our proposed method adaptively compensates the color brightness output from the projector by controlling a feedback system. We demonstrate compensation trials that use reformed color-mixing matrices and confirm that our proposed method offers excellent projection-based displays on 3D objects.

[Paper] Compressive Inverse Light Transport for Radiometric Compensation in Projection-based Displays

“…Even if users set up the projector-camera system by separately directing the projector and the camera toward the 3D objects, we aim to realize seamless and accurate image displays on uneven surfaces. In our previous work 37) ,…”

“…4(a); various isolated elements are dotted along the vertical axis in each matrix. When a single projector pixel connects with multiple camera pixels, it is well known that the light transport matrix has matrix structures that look like vertical line segments 37) .…”

“…11. We also tested our previous method 37) for a comparison; it obtains camera responses by handling 2N -kinds of push broom-type illuminations, i.e. vertical-and horizontal-line patterns (VHLP) and then estimates the light transport matrix by employing compressed sensing.…”

“…We use Fujii's adaptive compensation method 11) and our previous method 37) as benchmarks. The adaptive compensation handles only direct light reflected from 3D structures and compensates projector brightness based on the color variation detected on 3D objects.…”

“…In our previous work 37) , we demonstrated that the reformed color-mixing matrix is an effective approach to radiometric …”