Printing System Data Set Omission for Transmission Efficiency
Solution Overview
Problem
Existing printing systems face inefficiencies in data transmission speed due to the large size of Huffman tables required for lossy compression, especially when printing image data, which can lead to increased transmission times and interrupted printing processes.
Innovation Solution
A printing system that omits the transmission of redundant data sets during the printing process for each band of a page by comparing and reusing existing data sets, allowing for the selection of omitting either the entire or partial data set, thereby reducing data transmission and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If lossy compression is applied to image data to reduce transmission time, then the compression ratio increases and transmission speed improves, but the data set size (e.g., Huffman table) becomes significant relative to the compressed image data size
Solution Approach 1:
The printing control apparatus performs preliminary comparison of data sets (Huffman tables) before transmission, identifying commonalities between current and previous image data. This allows the system to prepare omission commands in advance, preventing the transmission of redundant data sets while maintaining the ability to reconstruct them at the printing apparatus side.
Solution Approach 2:
The invention extracts and transmits only the essential image data while separating out the data set (Huffman table) that can be reused from previous transmissions. By taking out the redundant data set from the current transmission and handling it separately through omission commands, the system reduces overall transmission data volume while preserving necessary compression functionality.
2Reliability
If the data set is transmitted with every compressed image data to ensure proper decoding, then the reliability of image reconstruction is maintained, but the total data transmission volume increases
Solution Approach 1:
The printing control apparatus provides feedback to the printing apparatus by transmitting omission commands that indicate which data sets can be reused from previous transmissions. This feedback mechanism allows the printing apparatus to reliably reconstruct the complete data set by combining received image data with previously stored Huffman tables, ensuring accurate decoding without redundant transmissions.
Solution Approach 2:
Instead of transmitting the actual data set (Huffman table) again, the system creates a reference to the previously transmitted and stored data set. The printing apparatus copies the existing Huffman table from its memory and applies it to the current image data, achieving reliable reconstruction while minimizing transmission volume.
3Manufacturing precision
If lossless compression is used to maintain image quality, then image quality is preserved, but the compression ratio is low and transmission time increases
Solution Approach 1:
The invention changes the compression parameter from lossless to lossy compression, accepting a controlled degradation in image quality in exchange for significantly higher compression ratios. This parameter change enables much faster transmission times while the data set omission mechanism ensures that the essential visual information is preserved through efficient reuse of compression algorithms.
Data Source
AI summary
The printing control apparatus compares, when printing a bit image, a data set of a transmitted compressed image data to a data set of an untransmitted compressed image data, omits transmission of the data set in the subsequent compressed image data when the data sets coincide with each other, and notifies the printing apparatus that transmission of the data set has been omitted with setting in a printing command. The printing apparatus holds the compressed image data in which the data set has been omitted, and, when it is notified that transmission of the part of the data set has been omitted, generates the bit image by reusing a part of the already existing data set and developing the held compressed image data.