Image Defocus Blur Estimation

摘要

Image defocus blur estimation techniques are described. In one or more implementations, fixed spatial frequencies that are usable to analyze an image for blur are selected. The selected spatial frequencies are input to a function used to determine frequency responses for pixels of the image. The frequency responses indicate a response of the pixels around a given pixel to the selected spatial frequencies. The spatial frequencies that are selected may be limited to spatial frequencies having a frequency magnitude from a set of discrete values. The discrete values may, for instance, range from a minimum frequency magnitude to a maximum frequency magnitude, and be spaced apart by a frequency magnitude increment. A number of frequencies that are selected at each magnitude may also be based on the frequency magnitude increment.

主权项

1. A method for implementing image processing operations that use an estimation of an amount of blur caused in images by lens defocus by one or more computing devices, the method comprising:
determining, for one or more pixels of an image, frequency responses that indicate a response of the pixels around a given pixel to spatial frequencies that are useable to analyze an image for the blur, the frequency responses determined according to a function that takes a selected spatial frequency set as input, and the spatial frequencies in the set that are selected as the input having frequency magnitudes from a set of discrete values; computing, for the pixels and based on the frequency responses, probabilities that the pixel is blurred with blur disc radii that correspond to different amount of blur caused in an image by the lens defocus; choosing, for the pixels, the blur disc radii that is determined most likely to have blurred the pixel based in part on the probabilities, the choosing effective to estimate the amount of blur caused by lens defocus for the pixels of the image; and generating estimated blur amount data for the pixels according to the blur disc radii chosen, the estimated blur amount data being used to implement one or more of the image processing operations.