Sunplus Technology Co., Ltd.

Wen-Cheng Ho

Jyh-Kai Chang

Chun-Chi Chen

Chih-Cheng Ku

Mine-Ta Yang

Kuo-Kuang Keng

A Joint Bi-level Image Group (JBIG) coding and decoding system, which provides a series of fully serial and parallel computational combinations in arithmetic coding and decoding to thereby reduce the complexity of JBIG arithmetic encoder and decoder and increase the processing speed. The JBIG coding system receives pixels and contexts of an image datastream and performs an adaptive arithmetic coding on the pixels in accordance with a pre-stored table and a probability prediction table for further performing a non-distortion compression on the image datastream. The JBIG decoding system receives data and contexts of a compressed datastream and performs an adaptive arithmetic decoding on the data of the compressed datastream in accordance with the pre-stored table and the probability prediction table to thereby obtain an image datastream.

JBIG coding and decoding system

An image scaling system includes a window memory, a longitudinal scaler, a buffer and a latitudinal scaler. The window memory temporarily stores partial data of N image lines. The longitudinal scaler performs a longitudinal scaling operation on the partial data of the N image lines to thereby produce partial data of a longitudinal image line. The latitudinal scaler performs a latitudinal scaling operation on the partial data of the longitudinal image line to thereby produce scaling-part data of a latitudinal image line. The longitudinal scaler and the latitudinal scaler use a window average to perform an image shrinking operation and a bi-linear interpolation average to perform an image expanding operation.

Image scaling system capable of saving memory

A block decoding method and apparatus capable of decoding and outputting data in a longitudinal direction, which scans a compressed datastream and accordingly obtains a start address in the compressed datastream for each MCUR of a decompressed image, such that the apparatus can obtain blocks rotated with 90 degrees by performing a Huffman decoding in a longitudinal direction, a de-zigzag arrangement, an inverse quantization, an IDCT and a rotation. Since the decoding direction is identical to the output direction of a printer, only a desired column of data in the decompressed image is temporarily stored for output and accordingly the required memory size is relatively reduced.

Block decoding method and apparatus capable of decoding and outputting data in a longitudinal direction

A print data method includes a slicing step, a compressing step and decompressing step. The slicing step divides a swatch of data to be printed and required by each motor movement into a plurality of slices, each having m bits to represent printed pixels and further divided into n segments, where m, n are integers. The compressing step uses an inter-slice compression to represent an (i+1)-th slice of data on a basis of an i-th slice of data for generating a compressed (i+1)-th slice of data and an (i+1)-th control character. The decompressing step uses an inter-slice decompression with respect to the inter-slice compression to restore the (i+1)-th slice of data from the compressed (i+1)-th slice of data for further printing.

Print data compressing method

The present invention provides an image coding apparatus and method, which can achieve a low-cost, real time, and high-performance coding process by utilizing a line buffer and an auxiliary buffer to execute a typical prediction process in JBIG encoding, a ping-pong buffer and a window template, and an adaptive encoder/decoder. The image encoding apparatus includes a typical prediction unit for storing input image data and performing typical predication in JBIG encoding of the input image data, a ping-pong buffer unit which has a plural sets of line memories for sequentially updating and storing the image data into corresponding addresses of the plural sets of line memories, and generating a template, a encoding unit for reading out the image data stored in the ping-pong buffer, and performing adaptive arithmetic encoding, and a control unit for controlling access to the ping-pong buffer unit between the typical prediction unit and the encoding unit.

JBIG coding apparatus and method with low cost, high-performance ping-pong buffer arrangement

A block decoding method and system capable of decoding and outputting data in a longitudinal direction, which obtains a start address in an input compressed datastream for each block of a decompressed image by a pre-scanned compressed datastream such that the system can obtain 90&#xb0;-rotated blocks by performing a Huffman decoding in a longitudinal direction, a 90&#xb0;-rotated zigzag arrangement, an inverse quantization and an IDCT. Since the decoding direction is identical to the output direction of a printer, only a desired column of blocks of the decompressed image is temporarily stored for output and accordingly required memory size is relatively reduce.

Block decoding method and system capable of decoding and outputting data in a longitudinal direction

A memory use and management method and system for a multi-pass printer. The system has a band buffer, a band buffer manager and a print engine. The band buffer receives and masks an input data, and stores masked data resulting from masking the input data. The band buffer manager is connected to the band buffer in order to start to print the masked data as the band buffer stores an amount of one complete print pass for a printhead of the printer. The print engine has the printhead and is connected to the band buffer such that the print engine receives the masked data from the band buffer and prints it by the printhead. Data amount stored in the band buffer can be represented by an equation, [(1+2+3+ . . . +j+j)/(i*j)]*S, where j indicates partitioned number of one complete print, and S indicates data amount required by one complete print.

Growing community of inventors

Shigang Shiang, Taiwan

Wen-Cheng Ho