Apple Inc.
Circuit for performing normalized cross correlation

Abstract:

Embodiments relate to a normalized cross correlation (NCC) circuit that can perform a normalized cross correlation between input patch data and kernel data. An interface circuit of an image signal processor receives input patch data from a source. Input patch data is data that represents a portion of a frame of image data from the source. The NCC circuit includes a filtering circuit and a normalization circuit. The filtering circuit receives the input patch data from the interface circuit and performs a convolution on the received input patch data or processed patch data derived from the input patch data with kernel data to produce convolution output data. The normalization circuit computes a normalized score output based on the convolution output data and the kernel data. The normalized score output includes normalization scores for each location of the convolution output data.