Specular and diffuse image generator using polarized light field camera and control method thereof
View Patent ↗An image generator is provided which obtains a specular image and a diffuse image from an image acquired by a polarized light field camera by separating two reflection components of a subject, and a control method thereof. The image generator may include a main lens, a polarizing filter part, a photosensor, a microlens array, and a controller that generates a single image in response to the electrical image signal and extracts, from the generated image, a specular image and a diffuse image that exhibit different reflection characteristics of the subject.
1. An image generator comprising:
a light source part that projects first polarized light that vibrates in one direction on a subject
a main lens configured to form an optical image of the subject on a focal plane;
a polarizing filter part configured to be placed on the focal plane and filters the optical image by using first and second polarizing filters that are at right angles to each other, wherein the first polarizing filter allows the first polarized light to pass therethrough, and the second polarizing filter allows second polarized light that vibrates in a direction vertical to the former direction to a therethrough;
a photosensor configured to convert the optical image into an electrical image signal;
a microlens array configured to be placed between the polarizing filter part and the photosensor, and comprise a plurality of microlenses that focus light on the focal plane; and
a controller configured to generate a single image in response to the electrical image signal, and extract, from the generated image, a specular image and a diffuse image that exhibit different reflection characteristics of the subject,
wherein:
an entire area of the polarizing filter part is divided into a first area consisting of the first polarizing filter and a second area consisting of the second polarizing filter;
the polarizing filter part is further configured such that light reflected from one point of the subject reaches the microlens array through the first and second polarizing filters; and
an image of the one point of the subject, which is captured by one of the plurality of microlenses, is divided into a first area formed by the first polarizing filter and a second area formed by the second polarizing filter.
2. The image generator of claim 1 , wherein the controller extracts the diffuse image by sampling regions that have passed through the second polarizing filter from the entire region of the generated image.
3. The image generator of claim 2 , wherein, the controller generates a sample image by sampling the regions that have passed through the first polarizing filter, and extracts the specular image by using the difference between the sample image and the diffuse image.
4. The image generator of claim 3 , wherein each of the microlenses projects part of the optical image on a predetermined region of the photosensor.
5. The image generator of claim 4 , wherein, the single image comprises a plurality of images that are generated by the microlens array.
6. The image generator of claim 1 , wherein the first and second polarizing filters are placed on the same focal plane.