公开(公告)号：US20040213471A1

公开(公告)日：2004-10-28

申请号：US10424141

申请日：2003-04-25

Applicant: STMicroelectronics S.r.I.

Inventor： Mauro De Ponti ,  Marco Ferretti ,  Matteo Boffadossi

IPC: G06K009/36 ,  G06K009/46

CPC classification number: H04N19/93 ,  H04N19/13 ,  H04N19/14 ,  H04N19/42 ,  H04N19/90 ,  H04N19/91

Abstract: A method of compressing a stream of pixel data relative a two-dimensional object, pixels of which are scanned by rows from a source device to a receiver device, includes defining an extended context window to include a pair of pixels following a last encoded pixel on the row being scanned and the respective triplets of neighboring pixels belonging to the preceding row. The method includes defining a first distinct context array of pixels of the extended context window for the pixel of the pair immediately following the last encoded pixel, and a second context array of pixels of the extended context window for the other pixel of the pair. An extended context value relative to each pixel of the pair is calculated, and the extended context value relative to a first pixel immediately following the last encoded pixel is compared with an extended threshold. If the extended context value is less than the extended threshold, then encoding the first and second pixels of the pair, and if the extended context value relative to the first pixel of the pair exceeds the extended threshold, then carrying out simultaneously a parallel processing and encoding of both pixels according to an encoding routine.

Abstract translation: 压缩像素数据相对于二维对象（其像素从源设备被扫描的行）到接收器设备的方法，包括定义扩展上下文窗口以包括在最后编码像素之后的一对像素 正在被扫描的行以及属于前一行的相邻像素的相应三元组。 该方法包括为紧邻在最后编码像素之后的对的像素定义扩展上下文窗口的第一个不同上下文阵列的像素，以及该对的另一个像素的扩展上下文窗口的第二上下文阵列的扩展上下文窗口。 计算相对于该对中的每个像素的扩展上下文值，并将相对于紧接在最后编码像素之后的第一像素的扩展上下文值与扩展阈值进行比较。 如果扩展上下文值小于扩展阈值，则对该对的第一和第二像素进行编码，并且如果相对于该对的第一像素的扩展上下文值超过扩展阈值，则同时执行并行处理和 根据编码程序编码两个像素。