Patent ID: 9699468
Date: 2017-07-04
CPC Classifications: G06K,G06T,H04N

Claim:
1. A method comprising: under control of a processing unit configured with executable instructions: partitioning an image into a plurality of image blocks including at least a first image block; determining a particular coding scheme used by a majority of image blocks in a neighborhood of the first image block in the image and determining whether a number or percentage of the majority of image blocks reaches a predetermined number or percentage, wherein the particular coding scheme is selected if the number or percentage of the majority of image blocks reaches the predetermined number or percentage; computing one or more of respective accuracies or coding efficiencies of a plurality of coding schemes for the first image block in response to determining that the number or percentage of the majority of image blocks does not reach the predetermined number or percentage; determining that a screen coding scheme is to be used for the first image block from among the plurality of coding schemes based at least in part on the one or more of the respective accuracies or coding efficiencies of the plurality of coding schemes for the first image block; selecting one or more pixel values from a distribution of pixel values as one or more major colors, the one or more major colors corresponding to one or more representative pixel values for a plurality of pixels included in the first image block; assigning one or more first index values to the one or more major colors; assigning one or more second index values to one or more escape pixels included in the first image block, the one or more escape pixels not belonging to the one or more major colors; classifying each pixel of the plurality of pixels into a major color of the one or more major colors or an escape pixel of the one or more escape pixels based on a pixel value of each pixel; converting the pixel value of each pixel into an index value based on which major color or escape pixel the pixel value is classified as; determining correlations among the plurality of pixels of the first image block based on a prediction algorithm and the index value of each pixel; and encoding the first image block into a code according to the prediction algorithm.