Patent ID: 9135681
Filing Date: 2015-09-15
Classification: G06T,H04N

Abstract:
1. An apparatus, comprising: a dynamic range calculation circuit configured to determine first and second dynamic ranges of first and second chrominance signals representing respectively first and second chrominance planes of a plurality of pixels in an image, and further configured to determine a dynamic range of a luminance signal representing luminance of the plurality of pixels; a filter circuit configured to low pass filter the first chrominance signal and generate a low pass filtered first chrominance signal; a weighting coefficient calculation circuit configured to compute a weighting coefficient on the basis of the dynamic ranges of the first chrominance signal, the second chrominance signal, and the luminance signal; and a weighted sum calculation circuit configured to generate a first output chrominance signal by computing a weighted sum of the first chrominance signal and the low pass filtered first chrominance signal using the computed weighting coefficient; wherein the filter circuit is further configured to compute a weighted average of the first chrominance signal within a neighborhood of a central pixel, each weight of the weighted average being a decreasing function of a difference between a luminance of a respective pixel within the neighborhood and a luminance of the central pixel, and being a decreasing function of a difference between a first chrominance plane of the respective pixel and a first chrominance plane of the central pixel and to set the computed weighted average, as the low-pass filtered first chrominance signal for the central pixel.