Stanford University researchers, led by electrical engineering Professor Abbas El Gamal, are developing a camera built around a multi-aperture image sensor whose pixels measure 0.7 microns, several times smaller than pixels in standard digital cameras. The pixels are arranged in arrays of 256 pixels each, with a tiny lens atop each array.
"It's like having a lot of cameras on a single chip," said Keith Fife, a graduate student working with El Gamal and another electrical engineering professor, Philip Wong. The main (objective) lens of an ordinary digital camera focuses its image directly on the camera's image sensor, which records the photo. The objective lens of the multi-aperture camera, on the other hand, focuses its image about 40 microns above the image sensor arrays. As a result, any point in the photo is captured by at least four of the chip's mini-cameras, producing overlapping views, each from a slightly different perspective.
The multi-aperture image sensor enables the camera to generate an accurate 3-D perspective of, for example, a person's eyes, nose, ears, and chin, suiting it to facial recognition for security purposes. Other uses include biological imaging, 3-D printing, and 3-D modeling of buildings. The researchers hope to fabricate the micro-optics on a camera chip. They believe the finished product may cost less than existing digital cameras because the quality of a camera's main lens is no longer paramount.
