Patent ID: 9686440
Date: 2017-06-20
CPC Classifications: G06K,H04N

Claim:
1. A method for rendering a scanned image comprising: receiving a scanned input image comprising a plurality of color channels; generating a neutral edge tag signal for the scanned input image by applying edge detection to a luminance channel of the scanned input image, applying a neutral pixel detector to one or more color channels of the plurality of color channels, and indicating an asserted neutral edge tag for a pixel of the scanned input image when an edge and a neutral pixel are detected for the pixel or indicating a non-asserted neutral edge tag for the pixel when an edge or a neutral pixel are not detected for the pixel; providing a color space conversion of the scanned input image to generate a second plurality of color channels; applying error diffusion to at least a first color channel of the second plurality of color channels for a first segment of the scanned input image based on the neutral edge tag signal not being asserted to generate an error diffusion rendered segment of an output image, wherein applying the error diffusion comprises eliminating error propagation from a second pixel to a third pixel in response to a feedback signal indicating an error diffusion value for the second pixel was not selected for the second pixel in the output image; and applying a thresholding to at least the first color channel for a second segment of the scanned input image based on the neutral edge tag signal being asserted to generate a neutral edge enhanced segment of the output image, wherein applying the thresholding comprises setting a fourth pixel to a value associated with black when a maximum first color value in a window around the fourth pixel is greater than a first threshold and a first color channel value for the fourth pixel is greater than a second threshold, and setting the fourth pixel to a value associated with white when the maximum first color value is greater than the first threshold and the first color channel value for the fourth pixel is not greater than the second threshold.