POLARIZATION IMAGE PROCESSING APPARATUS

摘要

A polarization image processing apparatus includes an illumination unit, a splitter, first and second polarization imaging devices, and a processing unit. The illumination unit illuminates a first surface of a transparent or translucent object with first illumination light polarized in a first direction and second illumination light polarized in a second direction, which crosses the first direction, alternately. Illumination axes of the first illumination light and second illumination light substantially coincide with an imaging axis of the polarization image processing apparatus. The splitter divides returning light into at least two light components. The first and second polarization imaging devices receive the light components. The processing unit detects a condition of a second surface of the object on the basis of first and second polarization images obtained by the first polarization imaging device and third and fourth polarization images obtained by the second polarization imaging device.

主权项

1. A polarization image processing apparatus comprising:
an illumination unit that illuminates a first surface of a transparent or translucent object with first illumination light and second illumination light alternately, the first illumination light being polarized in a first direction and the second illumination light being polarized in a second direction that crosses the first direction, an illumination axis of the first illumination light and an illumination axis of the second illumination light substantially coinciding with an imaging axis of the polarization image processing apparatus; a splitter that splits returning light that returns from the object into at least two returning light components; a first polarization imaging device that receives one of the at least two returning light components, the first polarization imaging device obtaining a first polarization image polarized in the first direction while the object is being illuminated with the first illumination light and obtaining a second polarization image polarized in the first direction while the object is being illuminated with the second illumination light; a second polarization imaging device that receives another one of the at least two returning light components, the second polarization imaging device obtaining a third polarization image polarized in the second direction while the object is being illuminated with the first illumination light and obtaining a fourth polarization image polarized in the second direction while the object is being illuminated with the second illumination light; and a processing unit that receives the first, second, third, and fourth polarization images from the first and second polarization imaging devices and detects a condition of a second surface of the object on the basis of a difference between a sum of the first polarization image and the fourth polarization image and a sum of the second polarization image and the third polarization image, the second surface being at a side opposite to a side of the first surface.