Coded Aperture Photography


Ashok Veeraraghavan, Ramesh Raskar, Amit Agrawal, Ankit Mohan and Jack Tumblin

Coded Aperture Camera: By simply inserting a mask in the aperture plane of the lens, one can achieve high quality deblurring and full resolution digital refocusing from a single coded aperture image.

Figure shows an extreme example of image defocus blur. The input photo on the left was blurred using a 7 by 7 invertible amplitude mask pattern. The amount of blur is 21 pixels. Deblurring results in sharp image. Note the small text on the right which is completely washed out in the captured photo. Also notice that the blur is not circular as in a traditional out-of-focus image, but corresponds to the shape of the mask used.

This coded aperture design is one of the two mask based designs proposed in our SIGGRAPH 2007 paper. The other design puts a high frequency mask close to the sensor to capture light field. It achieves digital refocusing a low spatial resolution, but does not require PSF estimation, since the entire light field is captured.

Following examples show full resolution digital refocusing. In these examples, a single coded aperutre photo was captured using Canon Digital Rebel XT SLR camera with 100mm focal length lens. After estimating layered depths, refocusing is achieved to bring out of focus regions into focus. Again notice that the out of focus blur is shaped according to the 7 by 7 mask pattern used while capturing the photo.

Notice that the face becomes sharp in the refocused image, while the painting gets blurred.

More details on SIGGRAPH 2007 Paper

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