Color processing of digital images

摘要

An embodiment relates to a method for color processing of an input image, the method including the steps of low-pass filtering of the input image to obtain a low-pass component, high-pass filtering of the input image to obtain a high-pass component, processing the input image for edge detection to obtain edginess parameters, and performing a color-space transformation of the input image based on the low-pass component, the high-pass component, and the edginess parameters.

主权项

1. An apparatus, comprising:
a low pass filter configured to generate a low pass value in response to a first color component of a pixel, the first color component of the pixel being in one of a plurality of channels in a first color space; a high pass filter configured to generate a high pass value in response to the first color component of the pixel; an edge detection circuit configured to generate an edginess parameter for the pixel indicating the likelihood the pixel is part of an edge or corner in a digital image containing the pixel; and a modifier circuit configured to transform the pixel from the first color space to a second color space including a plurality of channels, the modifier circuit configured to transform the pixel using a color transformation matrix including a plurality of coefficients, each coefficient that is utilized in generating a transformed value for the pixel in the second color space being adjusted using the low pass value of the pixel and the low pass values of corresponding pixels in the other channels and also being adjusted using the high pass value of the pixel and the high pass values of the corresponding pixels in the other channels, and wherein the edginess parameter of the pixel is utilized to adjust the high pass value of the pixel and the high pass values of the corresponding pixels but the edginess parameter is not utilized to adjust the low pass value of the pixel and the low pass values of the corresponding pixels in the other channels.